Home-Based Transcranial Direct Current Stimulation for Depression: From Feasibility to Clinical Implementation

Abstract

Home-based transcranial direct current stimulation (tDCS) for major depressive disorder (MDD) has progressed from early feasibility studies to an approved clinical treatment, highlighted by the US Food and Drug Administration’s 2025 premarket approval of the Flow FL-100 device. This milestone shifts the field from asking whether home-based tDCS can be delivered safely and effectively to defining how it should be implemented in routine clinical practice. This review synthesizes the current evidence on treatment outcomes, adherence, and safety, with an emphasis on factors that determine successful real-world implementation. Randomized controlled trials support the efficacy of home-based tDCS when delivered using adequate cumulative dosing, structured treatment protocols, and appropriate supervision or adherence monitoring. In contrast, shorter-duration and fully unsupervised protocols have generally shown less favorable outcomes, although the independent contributions of dose, treatment duration, and supervision remain difficult to disentangle. High adherence has been reported with user-centered device design, standardized training, remote monitoring, and scalable supervision models that maintain treatment fidelity while supporting broad clinical deployment. Home-based tDCS has demonstrated an excellent safety profile when delivered using standardized equipment, structured protocols, and active monitoring, exemplified by more than 30,000 supervised home-based sessions delivered through a large academic clinical program without reported skin lesions or serious adverse events attributable to tDCS. Remaining priorities include optimizing acute and maintenance dosing strategies, identifying predictors and biomarkers of response, defining the role of paired behavioral interventions, personalizing treatment for special populations - including perinatal patients, older adults, and adolescents - and integrating home-based tDCS within interventional psychiatry care pathways. The evidence supports a transition from proof-of-concept to clinical implementation, with future research focused on optimizing delivery, personalizing treatment, and expanding access to evidence-based neuromodulation for depression.

Plain Language Summary

Transcranial direct current stimulation (tDCS) uses a low electrical current applied through sponge electrodes on the scalp. Because tDCS devices are portable, treatment can be delivered at home rather than requiring repeated visits to a specialist clinic. This review examines the evidence for home-based tDCS for depression, including how well it works, its safety, treatment adherence, and how treatment should be delivered.

Recent clinical trials indicate that home-based tDCS can reduce depressive symptoms when delivered using appropriate treatment protocols, training, monitoring, and safety procedures. Home-based delivery can also make repeated treatment sessions easier to complete and may expand access to neuromodulation for people who cannot readily attend clinic-based treatment.

Important questions remain about the best treatment schedule, whether maintenance treatment can help sustain improvement, how much supervision is needed, and which patients are most likely to benefit. Future research should also determine whether accelerated treatment schedules and biomarkers can improve treatment and personalization, and how home-based tDCS can be safely adapted for populations such as older adults, adolescents, and people with depression during pregnancy or after childbirth.

Introduction

Major depressive disorder (MDD) is among the most prevalent and disabling conditions worldwide, affecting an estimated 280 million people and representing a leading cause of years lived with disability.¹ First-line treatments, including antidepressant medications and psychotherapy, are effective for many patients yet more than one-third do not achieve full remission despite adequate treatment trials.^2,3 This treatment gap is compounded by significant barriers to access, including geographic constraints, cost, stigma, and the burden of repeated required clinic visits, especially for existing neuromodulation therapies such as transcranial magnetic stimulation (TMS) and electroconvulsive therapy (ECT).⁴ The emerging evidence base for home-based tDCS includes patients earlier in the treatment pathway and is not limited to treatment-resistant depression, distinguishing its potential clinical positioning from neuromodulation approaches typically reserved for more treatment-resistant populations.

Transcranial direct current stimulation (tDCS) is a noninvasive brain stimulation technique that delivers low-intensity electrical current (typically 1 to 2 mA) through scalp electrodes to modulate cortical excitability. Anodal stimulation over the left dorsolateral prefrontal cortex (DLPFC), a region consistently implicated in MDD neurocircuitry,⁵ shifts membrane potentials toward depolarization, increasing cortical excitability to induce long-term potentiation-like changes in synaptic transmission.^6,7 Beyond local changes in cortical excitability, prefrontal tDCS may influence distributed networks involved in cognitive control, emotion regulation, and autonomic regulation, including frontolimbic and frontal-vagal circuitry.^8–10 These neurophysiological effects persist beyond the stimulation period and, with repeated sessions, are thought to underlie the antidepressant effects observed in clinical trials.⁷ tDCS is safe, portable, and sufficiently simple to operate, enabling treatment to be delivered outside conventional clinical settings. These practical advantages distinguish tDCS from other established neuromodulation treatments for depression, such as TMS and ECT, which generally require specialized equipment, trained personnel, and administration in dedicated clinical settings.

The transition from clinic-based to home-based delivery has been the defining development in tDCS for depression over the past decade. This shift was driven by accumulating evidence for the safety, tolerability, and efficacy of tDCS, accelerated by the need for remote treatment models during the COVID-19 pandemic,¹¹ and enabled by the development of portable, programmable, lower-cost devices. Early feasibility work established that remote delivery could be achieved safely with supervision via videoconferencing, maintaining the standardization and oversight of a clinical trial while eliminating the need for in-person visits.^12,13 This model enabled larger trials, longer treatment durations, better session adherence, and enrollment of patients who could not access traditional research settings.^14,15 Beyond improving convenience, home-based delivery has the potential to expand access to interventional psychiatry. Remote delivery may allow treatment of patients living in rural or geographically underserved areas, individuals without access to specialized neuromodulation centers, and those whose mobility limitations, disability, work obligations, or caregiving responsibilities make repeated clinic visits impractical.^4,16–18 In addition, the relatively low cost, portability, and scalability of tDCS compared with other neuromodulation modalities may lower barriers to implementation in resource-limited healthcare settings, thereby increasing access to evidence-based brain stimulation for underserved populations.¹⁹ Home-based tDCS should therefore be understood as a spectrum of delivery models, ranging from fully self-administered treatment to asynchronous monitoring and real-time remote supervision.

Regulatory approvals for tDCS devices for MDD are summarized in Table 1. Prior to the US approval, regulatory agencies in Europe (2014), South Korea (2021), Australia (2016), Canada (2016), and several other jurisdictions had already authorized tDCS devices for depression, supporting clinic-based, home-based, or hybrid delivery depending on the device and region. Although approved treatment protocols vary in session number and implementation, these authorizations have generally focused on repeated-course treatment in patients without treatment-resistant depression.

Table 1.

Global Regulatory Approvals of tDCS Devices for MDD, Including Home-Based Use. Summary of Worldwide Regulatory Approvals for tDCS Devices Used to Treat MDD, Including Clinic-Based, Home-Based, and Hybrid Delivery. Indications and Treatment Protocols Vary by Device and Jurisdiction. In December 2025, the Flow Neuroscience FL-100 Became the First FDA-Approved tDCS Device for MDD and the First Approved at-Home Noninvasive Brain Stimulation Device for This Indication

Country/Region	Regulatory Date/Status	Authority/Route	Device	Setting	Sessions/Protocol	Use Relative to Other Treatment	Indication/Population	Key Supporting Evidence	TRD Restriction in Public Record
European Union/EEA	CE 2014; MDR 2023	Class IIa; SGS Fimko (CE 0598)	Sooma tDCS	Clinic or supervised home use	Typical: 15 sessions/3 weeks; 30 min; maintenance individualized	Stand-alone or adjunctive	MDD; severity not specified	Lõokene et al, 2022;20 real-world study; n=410	Not stated
European Union/EEA	December 2025	CE Mark	Soterix Medical Depression tDCS-LTE	In-office treatment	Typical: 3–5 sessions/week; ~20 min; maintenance individualized	Non-drug treatment; supporting studies included monotherapy and adjunctive use	MDD; severity not specified	Brunoni et al, 2013; Brunoni et al, 2017	No; supporting evidence included a broad range of antidepressant treatment resistance
Canada	2016; licence 98137	Health Canada Class II	Sooma tDCS	Clinic or supervised home use	Typical: 15 sessions/3 weeks; 30 min; maintenance individualized	Manufacturer: Monotherapy or stand-alone	MDD; severity not specified	Lõokene et al, 2022;20 real-world study; n=410	Not stated
European Union and United Kingdom	Marketed since 2019	CE-marked Class IIa; UK via CE route	Flow FL-100	Home use; access varies by jurisdiction	Key trial: 36 sessions/10 weeks; 30 min	Monotherapy or adjunctive in trial	MDD; local severity wording not verified	Woodham et al, 2025;21 sham-controlled RCT; n=174	Not stated
Brazil	Marketed since 2020	ANVISA; registration details not verified	Flow FL-100	Home use; local access not verified	Key trial: 36 sessions/10 weeks; 30 min	Not verified	MDD; local severity wording not verified	Woodham et al, 2025;21 sham-controlled RCT; n=174	Not stated
South Korea	Apr 2021	MFDS marketing approval	Ybrain MINDD STIM+	Prescription home use; clinician oversight	Supporting study: 30–42 sessions/6 weeks; 30 min	Monotherapy in supporting study	Mild-to-moderate MDD in supporting study	Oh et al, 202322 (NCT04720040); multicenter single-arm study; n=61	Not stated; study excluded antidepressant use
Australia	ARTG 491325: Jun 10, 2025; prior ARTG 278349 (2016) canceled May 18, 2026	TGA Class IIa	Sooma tDCS	Clinic or clinician-managed home use	Typical: 15 sessions/3 weeks; 30 min; ARTG does not specify count	Not specified	MDD and specified chronic-pain conditions; severity not specified	Lõokene et al, 2022;20 real-world study; n=410	Not stated
Australia	ARTG 509725: Aug 21, 2025	TGA Class IIa	Flow FL-100	Home use under qualified practitioner supervision	Key trial: 36 sessions/10 weeks; 30 min; ARTG does not specify count	Not specified	Adults age 18+ with MDD; severity not specified	Woodham et al, 2025;21 sham-controlled RCT; n=174	Not stated
United States	FDA PMA: Dec 8, 2025 (P230024)	FDA premarket approval	Flow FL-100	Prescription home use; self-administered or clinician present	5/week x 3 weeks, then up to 3/week; 30 min; pivotal study: 36/10 weeks	Monotherapy or adjunctive	Adults age 18+ with moderate-to-severe current-episode MDD	Woodham et al, 2025;21 sham-controlled RCT; n=174	Yes; patients not considered medication-treatment-refractory

Notes: Oh et al 2023 reported the South Korean open-label multicenter study. Lõokene et al 2022 provides uncontrolled real-world evidence for Sooma tDCS. Woodham et al 2025 reports the pivotal randomized trial supporting Flow FL-100. Session counts reflect regulatory labeling where available or published trial protocols otherwise.

Abbreviations: ANVISA, Brazilian Health Regulatory Agency; ARTG, Australian Register of Therapeutic Goods; CE, Conformité Européenne; EEA, European Economic Area; EU MDR, European Union Medical Device Regulation; FDA, US Food and Drug Administration; MDD, major depressive disorder; MFDS, Ministry of Food and Drug Safety (South Korea); PMA, premarket approval; RCT, randomized controlled trial; tDCS, transcranial direct current stimulation; TGA, Therapeutic Goods Administration (Australia); TRD, treatment-resistant depression.

Within this broader regulatory landscape, approval of the Flow Neuroscience FL-100 for at-home treatment of MDD represents an important regulatory milestone in the evolution of home-based tDCS. The device received CE marking in Europe in 2019 and subsequent regulatory authorization in several additional markets, supporting its clinical use in Europe and other jurisdictions before US approval. On December 8, 2025, the US Food and Drug Administration granted premarket approval to the FL-100 for the treatment of moderate-to-severe MDD in adults who are not considered treatment-refractory to medication, either as monotherapy or as an adjunctive treatment. This decision represented the first US approval of a tDCS device for depression and the first FDA approval of an at-home noninvasive brain stimulation device for depression, marking an important regulatory milestone for home-based neuromodulation.²³

This regulatory transition reflects a broader maturation of the field. Early studies and reviews were necessarily focused on whether home-based tDCS could be delivered safely, feasibly, and with adequate oversight. More recent randomized controlled trials (RCTs), meta-analyses, and clinical implementation experience suggest that these foundational questions have been addressed under appropriately structured protocols.^15,24 The next challenge is to define how home-based tDCS should be optimized for real-world clinical use, including cumulative dose, treatment duration, supervision and monitoring, adherence support, maintenance therapy, patient selection, and integration with other evidence-based interventions. This review examines outcomes, adherence, and safety, with a focus on the transition from establishing the feasibility of home-based tDCS to optimizing its implementation in clinical practice.

Outcomes

Evidence from Randomized Controlled Trials

The randomized controlled trial evidence base for home-based tDCS in depression has grown substantially in recent years, although results have varied across study populations and implementation protocols (Table 2). Rather than supporting a simple positive-or-negative conclusion, the pattern of findings suggests that treatment outcomes depend on cumulative dose, treatment duration, supervision, adherence support, implementation characteristics, procedural safeguards, and individual patient characteristics.

Table 2.

Characteristics of Randomized Controlled Trials Evaluating Home-Based Transcranial Direct Current Stimulation (tDCS) for Major Depressive Disorder. Overview of Randomized Controlled Trials of Home-Based tDCS in MDD, Highlighting Differences in Study Design, Supervision Strategy, Treatment Dose, and Stimulation Parameters. Variations in Cumulative Dose, Treatment Duration, and Remote Supervision May Contribute to Differences in Clinical Outcomes Across Studies

Study	Sample	Population	Design	Home-Based Delivery Model	# Sessions	Current Intensity	Electrode Montage	Session Duration
Oh et al, 202225	58	MDD without psychotic features	Randomized, single-blind, sham controlled	Self-administered home tDCS using a mobile application; no supervision	Daily over 6 weeks	2 mA	Anode: not specified; cathode: right DLPFC	30 min
Kumpf et al, 202326,27	11	MDD	Double-blind, sham-controlled, parallel-group	Self-administered home tDCS; no supervision	Planned 30 sessions over 6 weeks; 5/week	2 mA	Anode: F3; cathode: F4	30 min
Kim et al, 202428	37	MDD and MCI	Randomized, double-blind, sham-controlled	Self-administered home tDCS; supervised	30 sessions over 6 weeks; 5/week	2 mA	Anode left DLPFC (F3); cathode: right DLPFC (F4)	30 min
Borrione et al, 202429	210	MDD	Three-arm, double-blind, sham-controlled	Self-administered home tDCS using a mobile application; no supervision	21 sessions over 6 weeks	2 mA	Anode: left prefrontal; cathode: right prefrontal	30 min
Woodham et al, 202521	174	Moderate/severe MDD	Fully remote, multisite, double-blind, sham-controlled	Self-administered home tDCS; live supervision at first session and app-based compliance monitoring thereafter	36 sessions over 10 weeks; 5/week for 3 weeks, then 3/week for 7 weeks	2 mA	Anode: left DLPFC; cathode: right DLPFC	30 min
Lee et al, 202530	141	MDD	Multisite, double-blind, sham-controlled	Self-administered home tDCS; no supervision	42 sessions over 6 weeks; once daily	1 mA, or 2 mA	Anode: F3; cathode: F4	30 min
Aktürk et al, 202531	20	MDD	Randomized, single-blind, sham-controlled	Self-administered home tDCS; asynchronously supervised	15 sessions over 3 weeks; 5/week	2 mA	Anode: F3; cathode: F4	30 min

The largest and most rigorously conducted trial to date is the pivotal registration trial by Woodham et al, published in Nature Medicine in 2025.²¹ This fully remote, multisite, double-blind, sham-controlled superiority trial enrolled 174 adults with moderate to severe non-treatment-resistant MDD across the UK and USA. Participants received active or sham tDCS using a 2 mA, 30-minute, left anodal DLPFC montage for 36 sessions over 10 weeks: five sessions per week for the first three weeks, followed by three sessions per week for seven weeks. The protocol combined a relatively high cumulative dose with structured implementation features, including live supervision at the first session and app-based adherence monitoring thereafter. In the sham condition, the same device and treatment schedule were used, but current was limited to a brief ramp from 0 to 1 mA over 30 seconds followed by a 15-second ramp down to 0 mA, repeated at the end of the session, to mimic the sensory effects of active stimulation.²¹

Active treatment produced significantly greater improvement compared to sham on the Hamilton Depression Rating Scale (HDRS) (decrease of 9.41 vs 7.14 points, 95% CI 0.51 to 4.01, P=0.012), corresponding to an absolute between-group difference in change of 2.27 points. Although the difference in mean HDRS change was modest, its clinical interpretation is strengthened by the substantially higher categorical response and remission rates with active treatment: response rates were 58.3% vs 37.8% and remission rates were 44.9% vs 21.8%, respectively.²¹ Discontinuation rates did not differ between arms.

Interpretation of these findings should consider the methodological challenge of maintaining blinding over an extended course of tDCS. Skin sensations associated with active stimulation may differ from those produced by sham, particularly across repeated sessions. In the Woodham et al trial, participants assigned to active treatment were more likely to believe that they had received active tDCS than those assigned to sham treatment.²¹ Although this does not negate the observed between-group differences, it underscores the importance of systematically assessing blinding integrity, treatment expectancy, and the potential influence of sensory cues in future home-based trials.

The 7.14-point HDRS improvement in the sham group also indicates substantial symptom improvement in the absence of active stimulation. The trial cannot determine the relative contributions of expectancy, natural symptom fluctuation, engagement associated with study participation and remote clinical contact, or concurrent stable treatment. Importantly, the protocol did not include a paired mindfulness intervention, and not all participants were receiving antidepressant medication: 62.6% were taking antidepressants at baseline, while 32.8% were treatment-free.²¹ Accordingly, the sham improvement should not be attributed to a single mechanism. The potential independent therapeutic contribution of supervision and structured treatment contact is discussed further in The Therapeutic Role of Supervision.

A subsequent follow-up analysis examined participants who contributed data during the post-randomization open-label active-treatment extension and longer-term follow-up.³² After the 10-week randomized phase, 111 (63.8%) participants opted to complete an open-label active treatment extension. Clinical gains were largely maintained, with continued tolerability and no new safety concerns, and optional continued device use suggested sustained participant interest beyond the controlled trial period.³² However, because follow-up data came from a subset of the original trial population and included open-label treatment with optional continued use, these results are best interpreted as supporting durability, feasibility, longer-term safety, and acceptability, rather than as additional randomized evidence of efficacy.

In contrast to the Woodham trial, several studies using shorter, less supervised, or more heterogeneous protocols have produced null or less definitive findings. Borrione et al conducted a three-arm, double-blind, sham-controlled RCT in 210 adults with MDD in Brazil, testing fully unsupervised home-use tDCS over 21 30-minute sessions across six weeks, with or without a concurrent digital behavioral therapy.²⁹ No significant differences were found between any of the three arms on HDRS scores at six weeks. Three features distinguish this protocol from the pivotal Woodham et al trial: it enrolled participants with antidepressant treatment-refractory depression, a population in which prior meta-analysis and systematic reviews have suggested lower response and remission rates,^33–36 used a shorter intervention than the 10-week Flow protocol, and included no study-staff contact during treatment. Because treatment duration, cumulative dose, supervision, and treatment resistance differed simultaneously from the Woodham trial, the relative contribution of each factor cannot be determined. A subsequent maintenance phase analysis of this cohort reported that participants who continued device use showed sustained symptom improvement over follow-up, though given the null primary result this should be interpreted as naturalistic observation rather than evidence of durable treatment benefit.³⁷

Earlier randomized evidence was more limited and less definitive. Oh et al conducted a randomized, single-blind trial in 58 adults with MDD without psychotic features, testing app-supported, self-administered home tDCS delivered 30 minutes daily for six weeks using a portable device.²⁵ Participants were trained to use the device and completed sessions at home, with mobile application–based management rather than session-by-session supervision. Over six weeks, depressive symptoms improved significantly on the Beck Depression Inventory, with greater improvement in the active than sham group, but between-group differences were not significant on clinician-rated measures, including the HDRS.²⁵ The study also highlighted practical implementation challenges: 13 participants discontinued treatment, including seven because of poor compliance and two because of mild forehead burns. These findings illustrate that feasibility alone is insufficient;²⁵ home-based protocols must also ensure adherence, safe electrode preparation, and reliable treatment execution.

Lee et al subsequently provided additional evidence on the feasibility and safety of self-administered home tDCS delivery in MDD.³⁰ This multicenter RCT enrolled 141 adults with MDD and compared adjunctive home-based tDCS delivered through a portable device across sham, low-intensity (1 mA), and high-intensity (2 mA) arms. Treatment consisted of 42 once-daily 30-minute sessions over six weeks. No significant between-group differences were observed for cognitive or depressive outcomes at week six, although treatment was generally safe and well tolerated.

Kim et al further expanded the evidence base by evaluating supervised home-based tDCS in a randomized, double-blind, sham-controlled trial involving 37 participants with MDD and comorbid mild cognitive impairment (MCI).²⁸ Participants self-administered 2 mA tDCS targeting the bilateral DLPFC (anode F3, cathode F4) for 30-minute sessions over six weeks under remote supervision. Active tDCS did not differ significantly from sham for depressive symptoms or cognitive outcomes, although home-based treatment was feasible and well tolerated.²⁸

More recent work has begun to refine the supervision question by testing implementation models that fall between fully supervised and fully unsupervised treatment. Aktürk et al reported a randomized, single-blind, placebo-controlled trial of home-use tDCS in depression that used asynchronous supervision.³¹ Participants could complete stimulation at home without live session-by-session monitoring, while the protocol retained structured oversight, adherence tracking, and safety follow-up. This model is clinically relevant because it may provide a scalable alternative to real-time tele-supervision while retaining structured oversight and safety monitoring. In this respect, the study helps sharpen the central implementation question for home-based tDCS: not simply whether stimulation can be delivered at home, but what level of supervision is sufficient to preserve adherence, safety, blinding, and treatment fidelity over repeated sessions.

Additional home-based studies further reinforce the importance of implementation quality. Kumpf et al reported a prematurely terminated pilot RCT in which burn-like cutaneous lesions led to early discontinuation after enrollment of only 11 participants, precluding efficacy conclusions and underscoring the importance of device design, electrode preparation, and procedural safeguards.²⁶ Park et al compared three-week and six-week home-based tDCS protocols and found significant reductions in depressive symptoms and improvement in cognitive performance in both MDD groups, without a significant difference between treatment durations.³⁸ However, the absence of a sham control arm limits interpretation, as improvements could reflect nonspecific effects, regression to the mean, or concurrent care rather than stimulation-specific benefit.

Overall, the randomized evidence supports the efficacy of home-based tDCS for MDD when delivered under optimized conditions, including adequate cumulative dose, sufficient treatment duration, adherence support, and appropriate procedural safeguards. Importantly, this evidence should be interpreted in relation to the target population: Flow was approved for adults with moderate-to-severe MDD who are not considered treatment-refractory to medication, either as monotherapy or adjunctive treatment. By contrast, several trials reporting null or less robust findings enrolled more treatment-resistant samples, in which antidepressant effects may be attenuated and harder to demonstrate. Thus, differences in treatment resistance, together with dose, duration, supervision, and adherence support, likely represent key determinants of observed treatment effects across home-based tDCS studies.

A recent meta-analysis by Moshfeghinia et al focused specifically on randomized home-based tDCS trials strengthens the overall evidence base.³⁹ Across five randomized trials including 415 participants, active home-based tDCS produced significantly greater improvement in clinician-rated depressive symptoms than sham stimulation, with excellent safety and high adherence.³⁹ These pooled findings are important because they indicate that the overall treatment effect is not driven solely by the pivotal registration trial, while still allowing for meaningful heterogeneity across protocols. Together with the individual trial evidence, this meta-analysis supports home-based tDCS as an effective treatment approach for depression under appropriately structured conditions and shifts the field from proof-of-concept toward optimization of treatment delivery.

Direct comparative evidence between tDCS and repetitive transcranial magnetic stimulation (rTMS) is limited. Earlier meta-analytic evidence found antidepressant effect sizes for tDCS comparable with those reported for rTMS, while broader network meta-analysis supports efficacy for several forms of noninvasive brain stimulation.^33,34,36 However, their implementation differs substantially because rTMS generally requires repeated clinic-based treatment, whereas tDCS can be delivered at home.

Evidence from Real-World Use and Clinical Program

Although randomized controlled trials establish efficacy under controlled conditions, they do not fully capture treatment delivery in routine clinical practice.

Lõokene et al reported a retrospective real-world study of 462 patients treated with tDCS in routine clinical practice across seven countries; 410 completed treatment and had complete outcome data. Treatment was delivered either in outpatient clinics or self-administered at home after clinic-based training, with a mean of 16 sessions. Clinical response and remission were reported in 54.9% and 19.5% of patients, respectively, with no serious adverse effects. However, the absence of a control group, completer analysis, and lack of separate outcomes for clinic- and home-treated patients limit conclusions regarding treatment efficacy and home-based delivery specifically.²⁰

In 2022, Charvet et al collected outcomes from an initial clinical cohort of 16 adults with treatment-resistant MDD treated through the first US clinical program delivering home-based tDCS by telehealth.⁴⁰ Established at NYU Langone Health in 2019, the program translated a remotely supervised research protocol developed beginning in 2014 into routine clinical care. The tDCS clinical program has since delivered more than 30,000 supervised home-based treatment sessions to patients across all 50 US states.⁴¹

Participants completed a 32-session, 10-week home-based tDCS protocol, with 30 minutes of stimulation per session paired with guided mindfulness meditation and live video supervision at every session. Significant improvement in depressive symptoms was observed as early as week two (MADRS 28.00 at baseline vs 17.12 at week two, p<0.001).⁴⁰ Acute response and remission rates were 75% and 63%, respectively, rising to 88% and 81% following the taper period. The small sample size and open-label design preclude conclusions regarding efficacy or comparison with sham-controlled trials. Nevertheless, these findings demonstrate the feasibility of implementing an intensive home-based treatment protocol within routine clinical care and provide preliminary support for the effectiveness of this delivery model. The observed outcomes likely reflect the combined effects of cumulative treatment dose, structured supervision, procedural fidelity, and paired behavioral activity, which cannot be disentangled in this uncontrolled cohort. These findings complement the randomized evidence by illustrating that intensive, supervised home-based tDCS can be implemented successfully within routine clinical practice.

Acute Dosing

Defining the optimal tDCS dosing regimen remains one of the most important unresolved challenges in home-based treatment of depression. A recent dose-response framework emphasizes that the therapeutic dosing regimen should not be reduced to a single parameter such as session number, current intensity, or session duration.⁴² Rather, the dosing regimen is multidimensional, encompassing stimulation magnitude, spatial configuration, temporal patterning, cumulative exposure, inter-session interval, and the biological state of the targeted circuit at the time of stimulation.⁴²

Existing trials suggest that no single component of the dosing regimen adequately predicts treatment response; null findings have occurred in protocols ranging from approximately 21 to 42 sessions, particularly when treatment duration was limited to six weeks or delivery was largely unsupervised.^29,30 Meta-analytic evidence of individual participant data suggests that antidepressant effects may continue to increase over time and that longer treatment courses, lasting at least six weeks and potentially extending toward 10 weeks, may be required to capture the full clinical effect.⁴³ The FDA-approved protocol for Flow FL-100 consists of 36 sessions over 10 weeks. Meta-analytic data from Nikolin et al indicate that effect sizes continue to increase up to 10 weeks and that treatment duration is among the strongest moderators of outcome.⁴³

Ren et al’s 2025 JAMA Network Open meta-analysis evaluated transcranial electrical stimulation modalities including tDCS. In the MDD subgroup, tDCS was not associated with a significant improvement in depressive symptoms relative to comparators, and substantial heterogeneity was observed across studies.⁴⁴ This heterogeneity limits conclusions regarding optimal protocols and likely contributes to variability in reported treatment effects. By comparison, successful home-based tDCS trials have generally employed relatively standardized protocols, most commonly left DLPFC stimulation at 2 mA for 20 to 30 minutes delivered over repeated daily sessions with remote supervision, app-based monitoring, or other adherence-support procedures.

Although 2 mA is the predominant current intensity in depression trials, available safety data extend to higher intensities under appropriately controlled conditions. However, antidepressant efficacy has not been shown to increase monotonically with current intensity, and adequately powered dose-ranging trials directly comparing 2 mA with higher intensities in MDD are lacking. Current intensity should therefore be considered one component of a multidimensional dosing regimen rather than assumed to have a simple linear dose-response relationship.

Current evidence supports relatively intensive dosing regimens, typically comprising 28 to 42 sessions delivered over approximately 6 to 10 weeks, although the optimal combination of session number, treatment duration, stimulation parameters, inter-session spacing, and supervision has not been established in comparative trials.

Home-Based Treatment Enables Adequate Cumulative Dosing

One of the principal advantages of home-based tDCS is that it enables intensive dosing regimens that would be difficult to deliver in conventional clinic-based care. Antidepressant response appears to depend not only on individual stimulation parameters, but also on the ability to deliver repeated sessions over sufficient time. Clinic-based protocols requiring 20, 30, or more sessions can become difficult to complete because of travel burden, scheduling constraints, cost, disability, or depressive symptom burden itself. Home-based delivery substantially reduces these logistical barriers, making more intensive and flexible dosing regimens feasible, including extended acute treatment, multiple-session-per-day protocols, and continuation or booster therapy.⁴⁵ These expanded dosing paradigms include the 36-session protocol evaluated in the pivotal registration trial, accelerated regimens delivering 50 sessions over two weeks, and continuation or booster schedules designed to maintain longer-term clinical benefit.^21,37,46,47

Maintenance Dosing

Maintenance treatment is a major clinical objective for many patients receiving home-based tDCS, yet the evidence base remains substantially less developed than for acute treatment. Direct evidence for structured booster treatment impact in active MDD remains limited, but several studies are informative. The strongest randomized evidence for a booster-style approach comes from Rajji et al, albeit in a prevention-focused population with remitted MDD and/or mild cognitive impairment rather than active depressive episodes.⁴⁷ In this large RCT of older adults, cognitive remediation combined with prefrontal tDCS was evaluated over long-term follow-up. Repeated booster blocks, five tDCS sessions twice yearly, were provided to sustain the effects of the initial eight-week intervention. The primary signal was not acute symptom improvement, but slowing of cognitive decline over time, making the study conceptually important for maintenance-oriented tDCS while limiting direct applicability to acute MDD treatment.⁴⁷

Available continuation and maintenance studies support further investigation of maintenance dosing, although controlled evidence remains limited. Aparicio et al reported 6-month continuation data from prior depression tDCS trials in which responders received ongoing twice-weekly tDCS; mean relapse-free survival was 17.5 weeks, and 73.5% remained relapse free at the end of the 6-month follow-up period.⁴⁸ Similarly, the PSYLECT maintenance-phase study followed 71 participants in a 6-month open-label continuation protocol in which responders received twice-weekly home-based tDCS, with or without digital behavioral therapy; relapse-free survival at 6 months was 75%.³⁷ This study further supports the feasibility and tolerability of maintenance tDCS in depression, while also underscoring that open-label continuation designs cannot establish controlled relapse-prevention efficacy.³⁷ In home-administered depression treatment specifically, Le et al described an acute, taper, and optional maintenance model in treatment-resistant depression, but this evidence came from a case series rather than a randomized trial.⁴⁹ Similarly, the Woodham follow-up provides useful longer-term safety and acceptability data after a randomized home-based MDD trial, but the post-randomization phase was open-label and optional rather than a controlled booster schedule.³²

Taken together, these studies support the feasibility and clinical rationale for maintenance and booster tDCS, but the optimal booster frequency, treatment duration, scheduling strategy, and supervision model for active MDD remain to be established.

Predictors of Response

Reliable clinical and demographic predictors of response to tDCS in MDD have not been established. Most evidence to date derives from clinic-based tDCS trials and individual-patient-data meta-analyses, in which variables such as baseline symptom severity, age, sex, and concurrent antidepressant use have been examined. However, none has shown sufficiently consistent or externally validated predictive value to guide clinical selection.^33,43,50 Whether these findings generalize to home-based tDCS is uncertain, particularly because treatment adherence, self-administration capacity, digital engagement, and the level of remote support may introduce additional determinants of outcome. This limits the ability to identify in advance which patients are most likely to benefit from home-based treatment.

Brunoni et al examined patient-level moderators of response in randomized, sham-controlled trials of tDCS for acute depressive episodes.³³ These analyses identified several factors associated with treatment outcome, including greater treatment resistance and concomitant benzodiazepine use, both of which were associated with a lower likelihood of clinical improvement.³³ Although these findings have not translated into clinically useful prediction models, the available evidence suggests that treatment resistance and certain concomitant medications may meaningfully influence treatment response.

The relationship between treatment resistance and tDCS response remains uncertain. Earlier individual-patient-data analyses identified greater treatment resistance as a predictor of poorer response, whereas a more recent individualized patient data (IPD) meta-analysis of 1246 participants did not identify treatment resistance as a significant moderator of clinical improvement.^{33,34,43,50,51} This issue is relevant when interpreting the Woodham trial, which excluded participants with two or more failed antidepressant treatments during the current depressive episode.²¹ These eligibility criteria limit generalizability to more treatment-resistant populations and preclude determining whether comparable efficacy would be observed in patients with greater levels of treatment resistance.

Concomitant benzodiazepine use may also warrant consideration. Prior patient-level analyses found that benzodiazepine use was associated with poorer tDCS outcomes, potentially reflecting a pharmacologic interaction with stimulation-induced plasticity or greater underlying clinical complexity.³³

Other predictor-focused studies have likewise yielded preliminary rather than clinically actionable findings. In a pooled analysis of three open-label studies involving patients with treatment-resistant depression, D’Urso et al found that demographic variables, including age, sex, and diagnosis (unipolar versus bipolar depression), were not associated with treatment response.⁵² Instead, greater baseline cognitive disturbance and psychomotor retardation, with a weaker association for anxiety/somatization, were associated with larger reductions in depressive symptoms following anodal prefrontal tDCS.⁵² However, because these findings were derived from retrospective analyses of open-label studies without external validation, they remain exploratory and cannot yet support individualized treatment selection. Recent meta-analytic evidence further suggests that treatment effects vary according to study-level characteristics, including diagnosis (unipolar versus bipolar depression), treatment context (monotherapy versus adjunctive therapy), and stimulation montage, highlighting the substantial heterogeneity of response across studies.⁵³ However, these study-level moderators should not be interpreted as validated predictors of individual patient benefit.

More recent predictor-focused studies have reinforced this uncertainty. A pooled analysis of two independent trials in unmedicated patients with MDD examined clinical and demographic predictors of response to anodal prefrontal tDCS.⁵⁴ Demographic variables were not predictive of treatment response; instead, greater baseline cognitive-affective symptoms, loss of pleasure, loss of interest, and sleep disturbance were associated with a higher likelihood of antidepressant response.⁵⁴ Machine-learning approaches have also been applied to antidepressant tDCS datasets, including an analysis of the ELECT-TDCS study showing that baseline clinical patterns may differentially predict response to tDCS and escitalopram.⁵⁵ However, more recent cross-trial prediction work using DepressionDC and ELECT-TDCS data found that model performance remains modest and that external generalizability is limited.⁵⁶

The existing literature suggests that patient-level heterogeneity is likely to influence tDCS outcomes, but current clinical and demographic predictors are not sufficiently robust for routine decision-making. Future studies should prospectively evaluate clinical, behavioral, and neurophysiologic predictors of response, including treatment-resistance status, baseline symptom profiles, concurrent pharmacotherapy, adherence patterns, and measures of cortical engagement. Emerging work on neurophysiologic and other biomarkers of acute response is discussed in the Optimization section.

Why Adherence Matters in Home-Based tDCS

Adherence should be understood not only as a feasibility metric, but as a fundamental determinant of effective treatment delivery. In repeated-session neuromodulation protocols, high adherence ensures that patients receive the intended cumulative therapeutic dose, whereas missed, shortened, or incorrectly completed sessions reduce the effective treatment exposure. A patient who completes 15 of 32 sessions has not necessarily failed to respond to treatment; they may not have received an adequate course of treatment.

Beyond Session Counts: Adherence as Treatment Fidelity

Adherence in home-based tDCS should be defined more broadly than session completion alone. It is more appropriately viewed as a treatment-fidelity construct that includes correct electrode placement, adequate electrode preparation, appropriate device use, tolerability, engagement with session procedures, and timely adverse-event reporting.^{12,15,16,24,27} This broader framework is especially important outside the clinic, where safe and effective delivery depends on coordination among the patient, device, and monitoring system. Consistent with this, a systematic review of in-home tDCS studies found substantial variability in monitoring approaches, including direct in-person monitoring, real-time videoconferencing, remote-controlled stimulation delivery, daily self-report diaries, phone or email contact, and digital tracking, with reported compliance ranging from 76% to 100% across studies.⁵⁷ This variability highlights that “home-based” tDCS is not a single implementation model, but a family of approaches that differ substantially in structure, oversight, and ability to ensure treatment fidelity.

Implementation Determinants of Adherence

The factors that drive adherence in home-based neuromodulation are not fully characterized, but the available evidence points consistently to three domains: the supervision model, the structure and usability of the delivery system, and the role of paired activity during stimulation. A fourth domain is also important: how adherence is measured and reported across studies. Each domain is addressed in turn below.

Adherence in Clinical Trials and Real-World Programs

Across clinical trial experience using the remotely supervised tDCS (RS-tDCS) protocol,^12,13,41 adherence has been consistently high.¹⁵ The largest implementation dataset supporting this model comes from Pilloni et al, who reported tolerability and feasibility across 6779 remotely supervised tDCS sessions in 308 participants across six clinical trials.¹⁵ High treatment fidelity was maintained across the two Class I randomized controlled trials reported. While this dataset was not specific to depression, it provides important implementation evidence that extended at-home tDCS protocols can be delivered safely and consistently at scale, including across protocols requiring up to 60 sessions, when standardized equipment, structured training, live remote supervision, and adverse-event monitoring are embedded in the intervention. This dataset is particularly informative because it moves beyond simple “attendance” and captures multiple dimensions of adherence. In remotely supervised protocols, a completed session is not merely a self-reported event; it reflects successful device setup, electrode preparation, real-time interaction with study staff, stimulation delivery, and tolerability monitoring. Therefore, high adherence in this context is better interpreted as evidence of treatment fidelity, not only participant persistence. In the depression-specific observational cohort described in Charvet et al, the 16 participants who completed the 32-session protocol did so with high fidelity across a six-week acute treatment phase and subsequent taper.⁴⁰ The combination of live video supervision, standardized equipment, and structured paired activity supported high treatment fidelity throughout the protocol, although the contribution of each implementation component cannot be determined.

Depression-specific trials further illustrate that adherence and implementation structure are separable from home delivery itself. In the Woodham et al RCT, participants completed the first session under live videoconference supervision, followed by app-based real-time adherence monitoring for all subsequent sessions; no live supervision was provided at any later session.²¹ This is distinct from the RS-tDCS model in which a clinician is present at every session. Discontinuation rates in the Woodham trial did not differ between active and sham arms (14.3% overall), demonstrating that supervised initiation with ongoing digital monitoring was sufficient to support completion across 36 sessions over ten weeks. By contrast, the Borrione et al trial operated with fully unsupervised home use and no researcher contact during sessions.²⁹ While adherence and completion rates were also reasonably high in that trial (>90%), with few dropouts, the absence of efficacy in the context of fewer sessions and no supervision makes it difficult to disentangle dose from structure as contributors to the null result.

Together, these trials suggest that completion alone may not capture treatment fidelity, engagement, or adequacy of delivered dose. These findings support the view that adherence is not simply a feasibility endpoint, but a determinant of treatment fidelity that enables delivery of the intended cumulative dosing regimen across extended treatment courses.

The Supervision Spectrum in Home-Based tDCS

The degree of supervision is an important implementation variable in home-based tDCS. Supervision should be understood as a spectrum rather than a binary distinction between “supervised” and “unsupervised” treatment. At one end are highly structured RS-tDCS models, in which a trained clinician is present by live videoconference for the full duration of every session, providing real-time electrode placement verification, immediate troubleshooting, continuous adverse-event monitoring, and structured therapeutic contact that may contribute to adherence independently of the stimulation itself.^12,13,15,16 At NYU Langone Health, this model transitions patients to reduced supervision only after they demonstrate independent competence against a standardized checklist, although this stepped approach has not itself been evaluated in comparative outcome studies.^58,59

Across published trials, supervision level does not vary independently of dose and duration, which limits what can be attributed to supervision alone. The Woodham trial occupied an intermediate position, with a single supervised session at the outset followed by app-based monitoring without ongoing live supervision.²¹ It achieved high adherence and significant antidepressant effects while also delivering a substantially higher cumulative dose (36 sessions over 10 weeks) than the trials discussed below. The independent contribution of supervision therefore cannot be determined.

Aktürk et al evaluated an intermediate asynchronous supervision model that replaced live session-by-session monitoring with structured oversight and safety follow-up, potentially offering a more scalable implementation approach.³¹ Whether this approach provides treatment fidelity, safety, and clinical outcomes comparable to live supervision remains unknown.

The Borrione trial represented a fully self-administered model, with no supervised initiation and no researcher contact during treatment sessions.²⁹ The protocol also differed from the Woodham trial in treatment duration and cumulative dose (21 sessions over 6 weeks versus 36 sessions over 10 weeks). The trial showed neither significant antidepressant efficacy nor important safety concerns. Because these implementation features varied simultaneously, the relative contributions of supervision, cumulative dose, and treatment duration to the differing outcomes cannot be determined.

Whether supervision contributes through therapeutic engagement, accountability, procedural safeguards, or a combination of these mechanisms, and to what extent its effects are independent of dose and duration, remains unknown. Trials that systematically vary supervision while holding treatment dose and duration constant are needed to define its independent contribution.

The Therapeutic Role of Supervision

The therapeutic role of supervision itself also warrants consideration. In addition to supporting procedural accuracy and safety, supervision may influence adherence through several overlapping mechanisms, including increasing accountability, reinforcing treatment routines, facilitating early troubleshooting, improving adverse-event detection, and providing reassurance during treatment. Even brief remote contact may contribute to the overall treatment experience for some patients.

Qualitative evidence also suggests that remote support may shape patients’ experience of home-based tDCS. Rimmer et al found that participants valued videoconference interactions as a source of support during treatment.⁶⁰ Similarly, a thematic analysis of home-based tDCS in bipolar depression found the intervention to be broadly acceptable, with participants describing themes related to perceived helpfulness, treatment burden, side effects, and gratitude within a protocol that incorporated real-time videoconference supervision for device setup and administration.⁶¹ Together, these findings suggest that remote contact may contribute to reassurance, treatment engagement, and acceptability. However, whether supervision independently improves adherence, treatment fidelity, or clinical outcomes remains uncertain because qualitative studies have not compared otherwise equivalent supervised and unsupervised protocols. Future studies should evaluate supervision as an independent implementation variable while controlling for dosing regimen, treatment duration, device design, and other implementation factors.

Equipment Design and Usability

Usability is not simply a convenience feature; it is a fundamental determinant of whether patients can consistently and correctly self-administer treatment over weeks or months. Equipment that is difficult to set up, uncomfortable to wear, or prone to technical failures will generate non-adherence regardless of how well the clinical protocol is designed. In home-based tDCS, usability therefore functions as a treatment-fidelity variable, influencing whether the prescribed dose is delivered as intended.

The evolution of tDCS hardware for home use has addressed several early barriers to reliable self-administration. Cap-based and headset designs with pre-positioned electrodes reduce the need for patients to identify electrode locations or assemble montages independently. Snap-in sponge electrodes, app-guided instructions, connectivity features, and placement-verification tools can further reduce setup errors and troubleshooting burden. The Flow FL-100 device that received FDA approval reflects this shift toward user-centered design, with fixed prefrontal electrode positioning and app-guided training at session initiation. These design features support treatment fidelity by increasing the likelihood of consistent electrode placement, appropriate electrode preparation, and correct session completion across repeated treatments.

Paired Activity and Session Structure

What patients do during stimulation is an important implementation variable that may influence both adherence and treatment response, the latter discussed further in the Optimization section. From an adherence standpoint, structured activity during the 30-minute session gives patients a defined task that anchors the treatment to a specific time and context, reducing the likelihood of sessions being skipped or abbreviated. In the RS-tDCS depression protocol described above, stimulation was paired with guided mindfulness meditation at every session to standardize the behavioral context and increase the likelihood that stimulation occurred during engagement of relevant regulatory circuits.⁴⁰ Whether structured paired activity improves adherence compared with passive stimulation remains uncertain, and this aspect of home-based treatment has received little systematic investigation.

Safety

The General Safety Profile of tDCS

The safety profile of tDCS has been well established across clinical and research applications. The 2026 updated international guidelines on low-intensity tES, endorsed by the European Society for Brain Stimulation and the International Federation for Clinical Neurophysiology, synthesized safety data from more than 300,000 sessions across healthy participants, patients with neuropsychiatric and other clinical conditions, and vulnerable populations including children, older adults, and pregnant individuals.²⁴ No serious adverse events attributable to tDCS were identified. Moderate adverse events were rare and limited to specific applications, while mild adverse events were common and typically consisted of transient sensations at the electrode site, including tingling, itching, and warmth, as well as headache or fatigue. Importantly, many of these sensations occur at comparable rates during sham stimulation, suggesting that they are attributable, at least in part, to electrode contact and procedural factors rather than active stimulation alone.¹⁵ Skin redness or erythema, however, is generally reported more frequently following active stimulation than sham. Although typically mild and transient, this difference may have implications for participant blinding, particularly in protocols involving repeated or closely spaced treatment sessions.⁶² Overall, safety is well supported for bipolar and multichannel configurations at intensities up to 4 mA and stimulation durations up to 60 minutes per day, parameters that encompass and exceed those commonly used in depression protocols.⁶³

Home-Based Specific Safety Considerations

The home-based context introduces safety considerations that are largely absent from clinic-based delivery. In supervised clinical settings, trained staff verify electrode placement, inspect skin condition, ensure adequate electrode preparation, and respond immediately to adverse events.⁶⁴ When treatment moves into the home, these safeguards must be incorporated into the treatment protocol rather than assumed from the clinical environment.

The most clinically significant adverse event in home-based tDCS is skin injury at the electrode site, ranging from transient erythema to, rarely, burns or lesions.²⁶ At standard stimulation parameters, clinically significant skin injury is not typically attributable to stimulation alone, but is more often associated with deviations from standardized procedures, including inadequate electrode moistening or uneven conductive gel preparation, use of dried-out sponges, repeated stimulation over compromised skin, or devices without sufficient fault-condition safeguards.^64,65 In the Woodham et al trial, two participants reported burns at the anode site, both attributed to insufficient sponge moistening; neither developed residual skin lesions or scarring, and both resumed treatment after a brief interruption.²¹ A more serious outcome occurred in the Kumpf et al pilot trial,^26,27 which was terminated early after five of eleven participants in the active arm developed skin lesions, again linked to procedural factors including use of tap water rather than saline to moisten sponges. Together, these cases indicate that skin-injury risk in home-based tDCS is largely procedural and preventable, but they also show that insufficiently structured home delivery can allow preventable events to occur and escalate. Consistent with this, recent technical analyses comparing at-home and in-clinic tDCS in depression emphasize that home-based safety depends on the specific delivery model, including electrode preparation, device safeguards, impedance monitoring, and supervision procedures.

Not All Home-Based tDCS Is Equivalent

A central message for clinicians, researchers, and regulators is that “home-based tDCS” encompasses a wide range of practices that differ substantially in equipment, electrode preparation, supervision, and monitoring, and that safety outcomes vary accordingly. Vogelmann et al conducted a comparative analysis of technical data from 229 at-home and 835 in-clinic tDCS sessions in depression and identified differences in safety-relevant parameters between settings.^66,67 Simani et al’s response to that analysis emphasized that the RS-tDCS experience, with its structured protocols, optimized equipment, and real-time oversight, demonstrates a safety profile comparable to in-clinic delivery when appropriate safeguards are in place.⁶⁴ This distinction has direct implications for the design of remote-administration trials and for the interpretation of their safety data. Adverse events associated with inadequately supervised or poorly designed protocols should therefore not be generalized to home-based tDCS as a whole.

The RS-tDCS Safety Record

The RS-tDCS model represents one structured approach developed to address these risks while preserving the accessibility advantages of home-based treatment. Its safety features include structured end-user training for participants and caregivers, pre-saturated single-use sponge electrodes that eliminate preparation variability, adaptive current control with voltage limits, real-time impedance monitoring, and live video supervision for session initiation with daily adverse event reporting. The 2026 updated international tES safety guidelines recognize remotely supervised tES as an established framework for home-based stimulation and note that it has been implemented in more than 60 human studies across adult and pediatric populations.²⁴ Rather than treating home use as inherently safe or unsafe, the guidelines emphasize that safety depends on structured training, standardized equipment, appropriate electrode preparation, impedance monitoring, adverse-event surveillance, and supervision procedures.²⁰

The safety record of the RS-tDCS model has been documented across a growing body of clinical and research experience. Pilloni et al reported no serious adverse events across 6779 remotely supervised tDCS sessions in clinical trials, with only isolated mild cutaneous events that resolved without intervention.¹⁵ Across cumulative clinical and research experience, encompassing more than 30,000 sessions in 777 participants, no skin lesions or burns have been observed.^64,65 This favorable safety profile has been consistent across protocols involving consecutive daily sessions, participants with neurological and psychiatric comorbidities, and delivery through a contactless telehealth platform. Together, these findings indicate that safety in home-based tDCS depends primarily on protocol design, equipment, training, and monitoring rather than on the home setting itself.

Adverse Events in the Depression-Specific Context

Adverse events reported in home-based tDCS depression trials are generally consistent with the broader tDCS safety literature. In the Woodham trial, skin redness was more common in the active than sham group at week 10 (63.5% vs 18.5%), as were skin irritation (6.9% vs 0%) and difficulty concentrating (14.1% vs 3.7%).²¹ No between-group differences were observed for headache, neck pain, scalp pain, itching, burning sensation, sleepiness, or acute mood changes.²¹ No device-related serious adverse events were reported, and no participants developed mania or hypomania. Across the broader evidence base summarized by Antal et al, adverse-event frequency, severity, and type in clinical populations are comparable to those observed in healthy participants, and combined interventions pairing tDCS with other modalities have not been associated with increased safety risk.^24,68

A depression-specific safety consideration is the potential for psychiatric symptom destabilization, including hypomania, mania, or, less commonly, emergent psychotic symptoms, particularly in individuals with undetected bipolar disorder or other vulnerability to mood or psychotic disorders. Available evidence does not suggest that tDCS at standard parameters is a significant trigger for manic symptoms, and the Woodham trial reported no cases of hypomania or mania across 173 participants treated over 10 weeks.²¹ Nevertheless, screening for bipolar history and monitoring for emergent hypomanic symptoms remain appropriate clinical safeguards, particularly as home-based tDCS expands beyond controlled trial settings.

Monitoring Recommendations

Based on the cumulative evidence and our program’s experience, several safety practices are recommended for home-based tDCS in depression. Electrode preparation should use either pre-saturated single-use sponge electrodes or standardized saline preparation materials validated for the specific device, together with explicit patient training regarding both inadequate and excessive moistening: insufficient moistening can increase impedance and contribute to skin irritation, whereas excessive saline can lead to dripping or bridging across the scalp, reducing controlled current delivery. Skin inspection should be incorporated into supervised sessions, particularly at the anode site over the left DLPFC where current density is highest. In less supervised or unsupervised protocols, participants should be trained to inspect the skin before and after stimulation, recognize early signs of irritation or injury, and pause treatment and report concerns promptly rather than continuing stimulation over compromised skin. A structured adverse-event reporting mechanism should be available and actively used, with dedicated contact available to patients between sessions. Devices should incorporate adaptive current control and impedance monitoring with automatic shutdown on fault detection. Patients with active skin conditions at electrode sites should not proceed with stimulation until the skin has healed. These practices are not onerous and are already embedded in well-designed protocols; the challenge for the field as home-based tDCS scales is ensuring that they are maintained consistently outside research settings, including in models with reduced or no live supervision.

Optimization and Future Directions

Accelerated (Spaced) Protocols

Most established depression protocols have relied on once-daily weekday sessions delivered over several weeks, and these schedules remain the most clinically mature approach. Accelerated or spaced dosing regimens represent an important emerging direction. By compressing treatment into multiple daily sessions, accelerated protocols, often implemented as spaced protocols, may increase cumulative exposure while reducing the overall time to clinical response, a feature that could be particularly relevant for patients with severe symptoms, or time-sensitive treatment needs.⁴⁵

Early evidence indicates that intensified tDCS schedules can be feasible, although the evidence base remains preliminary. For example, a randomized pilot study tested ten 30-minute tDCS sessions over five days and reported encouraging remission outcomes in depression.⁶⁹ Couture et al also reported significant remission in treatment-resistant MDD after a substantially more intensive regimen of 50 sessions over two weeks, delivered as five 20-minute sessions per day at 2 mA.⁴⁶ Importantly, however, tolerability and skin safety require particular attention under accelerated conditions. In the Couture study, 62% of participants developed mild contact dermatitis under the anode, underscoring that repeated daily electrode application may introduce risks that are less prominent in conventional once-daily protocols.^46,62 These findings emphasize that accelerated protocols require explicit procedures for skin inspection, standardized electrode preparation, adequate hydration of sponge electrodes, careful monitoring of contact sites, and predefined criteria for treatment interruption or modification if irritation develops.

If accelerated (spaced) protocols are validated in larger randomized trials and independently replicated, home-based delivery can become especially well-suited to this application. The practical burden of attending multiple clinic visits per day would be prohibitive for many patients, whereas supervised home administration could make high-frequency dosing more scalable and patient-centered. At present, however, spaced home-based tDCS should be viewed as a promising research direction rather than an established clinical recommendation. Future studies should determine whether accelerated dosing improves speed or magnitude of antidepressant response, whether benefits persist after treatment, and how safety, adherence, and skin tolerability compare with conventional schedules.

Paired Activity and State-Dependent Effects

One of the most practically important and underexplored variables in home-based tDCS is what patients are doing during stimulation. tDCS does not act on the brain in isolation; rather, it changes the excitability and plasticity of neural systems that are already active at the time stimulation is delivered.^70–72 This state-dependence means that the cognitive, emotional, and behavioral context of stimulation is not incidental. It may help determine whether stimulation engages the intended circuit, produces nonspecific effects, or fails to meaningfully modulate the target network.

The theoretical rationale for pairing tDCS with targeted activity is therefore strong. If stimulation is applied while a relevant circuit is actively engaged, the induced change may be more functionally specific than stimulation delivered during passive rest or unstructured activity. In depression, the left dorsolateral prefrontal cortex is implicated in cognitive control, emotion regulation, attentional bias, and top-down modulation of limbic circuitry.⁵ Pairing prefrontal tDCS with tasks that activate these functions, such as working memory training, cognitive control exercises, attentional bias modification, positive affective processing, or structured mindfulness practice, could in principle enhance engagement of the antidepressant target.^73,74

Clinic-based studies provide partial support for this premise, although findings are not yet definitive. Brunoni et al reported that concurrent cognitive control training combined with tDCS was associated with antidepressant benefit in a randomized pilot study, supporting the idea that task engagement may shape clinical response.⁷⁵ By contrast, Aust et al found that adding tDCS to a structured cognitive behavioral therapy program did not significantly improve depression outcomes in a larger randomized clinical trial.⁷⁶ These mixed findings suggest that the question is not simply whether tDCS should be paired with “activity”, but which activity, at what time, at what intensity, and in which patients.

This issue may be particularly important for home-based delivery. In clinic-based trials, patients are usually observed during stimulation, and behavior during sessions is often constrained by the protocol. At home, patients may meditate, complete cognitive training, watch television, use their phone, talk with family members, or rest quietly, unless the session structure explicitly limits these behaviors. Such variability represents a largely uncontrolled source of heterogeneity that may influence treatment response. Whether specific paired activities produce superior outcomes compared with structured rest remains unknown, but home-based platforms are well positioned to test this directly because digital tasks can be standardized, time-locked to stimulation, and monitored remotely.

Biomarkers of Response

The limited ability to identify, before or early in treatment, which patients are most likely to benefit from tDCS remains a barrier to efficient clinical implementation. Biomarkers may help, but their role should be defined precisely. As outlined by Bikson,⁷⁷ biomarkers in neuromodulation are measurements used to guide, adjust, or withhold stimulation dose within a treatment strategy, rather than simply biological correlates of outcome. This framework distinguishes predictive biomarkers, baseline measures that inform treatment decisions without necessarily changing in response to stimulation, from responsive biomarkers, which are measured during or after treatment and used to guide it based on their change. In depression, a baseline measure identifying likely responders would be predictive; an acute change during or after stimulation is better understood as a responsive biomarker or target-engagement marker, indicating target engagement but not necessarily later clinical improvement unless that relationship has been prospectively validated.

Current biomarker evidence should be interpreted cautiously. Several candidate markers are promising for mechanistic understanding and treatment monitoring, but none has been sufficiently validated to guide routine patient selection, dosing, or clinical decision-making in depression. A mature depression-specific biomarker literature does not yet exist, although reviews and theoretical work have addressed biomarkers and inter-individual variability in noninvasive neuromodulation more broadly. Existing work has examined EEG, TMS-derived cortical excitability, functional connectivity, autonomic measures such as heart rate variability (HRV), behavioral markers of emotional processing, and computational electric-field modeling.^8,78–82 These approaches serve different purposes: some may identify responders likely before treatment, whereas others may indicate whether the intended circuit is being engaged during treatment. Future studies should define the intended biomarker role explicitly, test whether it adds value beyond clinical measures alone, and determine whether biomarker-guided adaptation of dose, montage, paired activity, or supervision improves outcomes.

In the longer term, these approaches may support closed-loop or adaptive tDCS, in which stimulation parameters are adjusted based on ongoing physiological or behavioral feedback. Baseline biomarkers could inform patient selection or starting dose, whereas responsive biomarkers could guide adaptation of current intensity, session number, treatment duration, paired activity, supervision, or maintenance dosing. Home-based tDCS is well suited to this approach because digital platforms and wearable sensors can facilitate repeated physiological and behavioral assessments across sessions without additional clinic visits. Closed-loop tDCS for depression remains an aspirational goal rather than an established clinical approach, and prospective studies are needed to determine whether biomarker-guided adaptation improves outcomes beyond fixed-dose protocols.

Patient Selection and Personalization

Reliable individual-level predictors of antidepressant response to tDCS have not yet been established.⁵¹ Across studies, variables such as baseline severity, age, sex, antidepressant use, episode duration, and treatment history have been examined, but no single clinical characteristic has consistently identified responders. Individual-patient-data meta-analyses support the antidepressant efficacy and acceptability of tDCS at the group level, but they also highlight substantial interindividual variability in clinical response.^33,50 Earlier analyses associated greater treatment resistance with poorer response, but this has not been consistently replicated in subsequent individual-patient-data meta-analysis.^{33–35,50,51}

This interindividual variability likely reflects both biological and technical factors. At a fixed nominal current intensity, the electric field reaching the cortex varies across individuals because of differences in skull thickness, scalp-to-cortex distance, cortical folding, cerebrospinal fluid distribution, and tissue conductivity. As a result, two patients receiving the same 2 mA stimulation protocol may receive meaningfully different electric-field magnitudes in the intended DLPFC target. This may be particularly relevant in depression, where clinical protocols often use scalp-based electrode placement rather than individualized anatomical targeting. Evidence that individual neurophysiological measures can correlate with tDCS electric-field strength further supports the importance of individualized dose considerations.⁸³

Computational modeling offers one route toward personalization. MRI-informed models can estimate current flow and help determine whether a given montage adequately engages the intended cortical region. In the future, such models may support individualized electrode placement, current intensity selection, or montage optimization.⁸⁴ However, computational modeling alone is unlikely to be sufficient unless integrated with clinical outcomes and measures of target engagement. A more mature personalization framework may require combining clinical predictors, anatomical modeling, baseline neurophysiology, and early within-treatment biomarkers. For example, Martin et al showed that pretreatment attentional processing speed may predict antidepressant response to tDCS, illustrating how baseline behavioral markers could contribute to future personalization strategies.⁸⁵

Integration into the Interventional Psychiatry Pathway

Home-based tDCS has been shown to be feasible and safe in major depressive disorder, supporting its integration as a remotely delivered component of broader interventional psychiatry care pathways. This framing is consistent with recent calls to advance brain stimulation toward more accessible, scalable, and potentially earlier-line psychiatric care models, including wearable or disposable electrotherapy approaches.¹⁷ Its advantages are primarily practical and safety-related: it is portable, repeatable, well-tolerated, associated with a favorable safety profile, has relatively few contraindications, and is compatible with supervised home-based delivery. These characteristics make it potentially useful at several points in care.

First, tDCS may function as a bridging intervention. Many patients experience delays before starting psychotherapy, medication management, TMS, esketamine, ECT, or specialty interventional psychiatry evaluation. A home-based intervention that can be initiated through telehealth could provide an active treatment option during these waiting periods, particularly for patients with moderate symptoms or limited access to clinic-based care. Second, tDCS may serve as an augmentation strategy. Because it can be combined with antidepressant medication, psychotherapy, mindfulness practice, or cognitive training, it may fit naturally into multimodal treatment plans rather than requiring patients to choose between biological and behavioral approaches. Recent randomized sham-controlled studies have also evaluated combined rTMS and tDCS approaches in major depressive disorder, including protocols targeting depressive and anxiety symptoms as well as cognitive outcomes, further supporting the rationale for multimodal neuromodulation strategies.^86–88 Sequential neuromodulation strategies have also been proposed, including protocols in which tDCS is used to prime intermittent theta burst stimulation (iTBS) before ECT in treatment-resistant depression.⁸⁹ Although outcome data from such approaches remain limited, these designs further illustrate how tDCS may be positioned within multi-step interventional psychiatry pathways rather than as an isolated intervention. Third, home-based tDCS may have a role in relapse prevention or maintenance. Depression is recurrent, and patients who respond to an acute intervention often require ongoing strategies to preserve benefit. Booster or taper schedules are particularly feasible at home because they avoid repeated clinic visits. The Rajji et al trial in older adults with remitted depression and mild cognitive impairment suggests that repeated tDCS paired with cognitive remediation may have value beyond acute symptom reduction, including possible preservation of cognitive function in the long term.⁴⁷ Maintenance-oriented home-based protocols have similarly incorporated taper schedules, reflecting the hypothesis that tDCS may be most clinically useful when integrated longitudinally rather than delivered only as a short acute course.

Special Populations: Perinatal

The home-based delivery model may be particularly valuable for populations whose access to clinic-based treatment is limited. Perinatal women represent one such group, because depression and anxiety during pregnancy and the postpartum period are common, clinically consequential, and often complicated by concerns about medication exposure, breastfeeding, fetal or neonatal safety, stigma, fatigue, childcare responsibilities, and difficulty attending frequent clinic visits. These barriers make a portable, non-pharmacological intervention such as tDCS conceptually attractive in this population.

Early evidence suggests that tDCS may be feasible during pregnancy, although the evidence base remains limited. A three-week pilot randomized controlled trial enrolled women with antenatal depression between 14 and 32 weeks’ gestation who had declined antidepressant medication and found that active tDCS was feasible, acceptable, and not associated with serious adverse events. Although post-treatment depression scores did not differ significantly from sham, remission at four weeks postpartum was higher in the active group, supporting further evaluation in a definitive randomized trial.⁹⁰ In a subsequent open-label pilot study, Kurzeck et al enrolled women with major depressive disorder after 10 weeks’ gestation showing the feasibility and acceptability of tDCS for depression during pregnancy under clinical supervision.⁹¹ A systematic review of transcranial electric stimulation during the perinatal period similarly concluded that these approaches are promising with no serious effects, but emphasized that available evidence is still sparse and that larger controlled studies are needed to establish efficacy and safety.⁹² Thus, while the non-pharmacological nature and portability of tDCS make home-based delivery especially appealing for perinatal depression, fetal and neonatal safety data remain limited.^93,94

Future perinatal protocols should include obstetric oversight, systematic adverse-event monitoring, careful documentation of pregnancy, delivery, breastfeeding, and neonatal outcomes, and conservative stopping rules. Home-based delivery has the potential to reduce travel burden and improve access.

Special Populations: Older Adults and Adolescents

Home-based tDCS may be particularly relevant for older adults, who often face barriers to repeated clinic-based treatment, including reduced mobility, medical comorbidity, transportation limitations, caregiver dependence, and polypharmacy. In this population, remote delivery may reduce treatment burden while allowing stimulation to be integrated with cognitive remediation, behavioral activation, or other structured activities. For example, Rajji et al reported that repeated tDCS paired with cognitive remediation in older adults with remitted major depression and mild cognitive impairment may have value beyond acute symptom reduction, including possible preservation of cognitive function over time.⁴⁷ These findings support the broader rationale for home-based protocols that can be delivered longitudinally and with lower travel burden.

However, home-based use in older adults requires specific safeguards. Protocols should account for cognitive impairment, sensory deficits, reduced manual dexterity, fall risk, medical complexity, and the possibility that patients may need caregiver support to correctly prepare electrodes, position the device, and report adverse events. Remote supervision should include clear procedures for skin inspection, device placement verification, adherence monitoring, and assessment of confusion, fatigue, headache, dizziness, mood worsening, or changes in cognition. Medication changes, unstable medical illness, and implanted or electronic medical devices should also be carefully reviewed before treatment.

Adolescents are another population in which home-based tDCS could improve access, particularly when frequent clinic visits are difficult because of school schedules, family logistics, or limited availability of specialty care.⁹⁵ However, adolescent protocols require a higher threshold for caution because of ongoing neurodevelopment, consent and assent requirements, caregiver involvement, and the need for close monitoring of clinical risk.⁹⁶

Emerging evidence suggests that tDCS is feasible and well tolerated in youth depression, with recent work combining a systematic review and a pilot randomized controlled trial demonstrating high treatment adherence, acceptable tolerability, successful blinding, and no serious adverse events. Nevertheless, the review identified only a small number of heterogeneous studies with substantial risk of bias, underscoring that the evidence base remains preliminary and insufficient to support routine clinical implementation.⁹⁷ Other studies have begun to evaluate neuromodulation approaches involving tDCS in adolescent depression, including combined rTMS and tDCS protocols, but these data remain preliminary and do not establish home-based tDCS as a treatment for adolescent depression.⁸⁸ Evidence from other pediatric populations suggests that remotely instructed home-based tDCS can be feasible with appropriate supervision,^98,99 but these findings should be extrapolated cautiously to adolescent mood disorders. Home-based adolescent protocols should therefore include parent or guardian training, age-appropriate instructions, supervised electrode placement, structured adverse-event reporting, and frequent assessment of suicidality, irritability, sleep disruption, treatment-emergent activation, and clinical deterioration. At present, home-based tDCS for adolescent depression should be regarded as investigational and limited to carefully supervised research protocols.

Conclusion

Over the past decade, home-based tDCS for depression has progressed from a promising experimental approach to an approved clinical treatment. The FDA PMA of the Flow FL-100 device in December 2025 marks an important regulatory milestone, but it also raises the stakes for answering the questions that controlled trials have left unresolved. Approval establishes that home-based tDCS demonstrated efficacy under specific, well-defined conditions; it does not resolve how to optimize delivery, who is most likely to benefit, or how to maintain outcomes over time in the heterogeneous patients who will seek treatment outside of research settings.

The evidence reviewed here supports several preliminary conclusions. Outcomes are generally favorable when treatment is delivered using relatively intensive dosing regimens over sufficient time, with current evidence supporting protocols comprising approximately 28 to 42 sessions delivered over 6 to 10 weeks. The distinction between supervised and unsupervised delivery is clinically meaningful, and the comparison between the Woodham and Borrione trials illustrates how dose and supervision co-vary in ways that make attributing failure to any single factor difficult.^21,29 Safety is favorable when standardized protocols, appropriate equipment, and structured monitoring are in place.^15,16,24 Adherence is supported by supervision, device usability, and structured session content, and should be viewed as a determinant of treatment fidelity rather than simply a feasibility outcome.

Important limitations remain in the current evidence base. The number of large sham-controlled home-based trials remains small, and protocols vary substantially across studies in supervision, session count, duration, and electrode preparation. Many real-world datasets are observational or open-label, limiting causal inference. Blinding integrity remains a broader challenge in tDCS research, particularly in longer-duration studies where skin sensations may differ between active and sham conditions. Evidence is limited in highly treatment-resistant populations, and optimal maintenance strategies remain undefined. These gaps should temper the confidence with which recommendations are made as home-based tDCS scales into routine clinical practice.

Several important questions remain open. Reliable clinical, demographic, or biological predictors of treatment response have not yet been established. The role of paired activity during stimulation is theoretically compelling but remains incompletely tested. Candidate biomarkers, including EEG, TMS-derived measures of cortical excitability, functional connectivity, autonomic measures such as heart rate variability, behavioral measures of emotional processing, and computational electric-field modeling, may eventually support patient selection, assessment of target engagement, and adaptive treatment strategies. However, none has yet been sufficiently validated to guide routine treatment selection, dosing, montage optimization, or other clinical decisions.

The home-based model offers advantages that extend beyond convenience. It enables the sustained, repeated dosing that appears necessary for durable antidepressant effects while expanding access to evidence-based neuromodulation for patients who live far from specialized treatment centers or face transportation, disability, work, caregiving, or other barriers to repeated clinic attendance. As portable, scalable technologies mature, home-based tDCS also has the potential to reduce disparities in access to interventional psychiatry by making neuromodulation more widely available across geographically and socioeconomically diverse populations. It also positions tDCS as a complementary component of the interventional psychiatry pathway, serving as a bridge, augmentation strategy, or maintenance intervention depending on a patient’s stage of care.

Pending further comparative evidence, clinical implementation should remain anchored to evidence-supported and device-authorized treatment protocols, with appropriate patient selection, standardized electrode preparation and device training, and structured monitoring for adherence and adverse events. Realizing this potential requires that the field move beyond asking whether home-based tDCS produces a measurable antidepressant effect and toward the harder questions of for whom, at what dose, with what structure, and within what care pathway it delivers durable improvement. The available evidence supports that transition. Future research should focus on defining optimal implementation strategies, identifying patients most likely to benefit, and determining how home-based tDCS can be integrated most effectively into routine clinical care.

Disclosure

Dr Giuseppina Pilloni reports grants or contracts from National Multiple Sclerosis Society (NMSS), NIH NIBIB, NIH NIDA; consulting fees from Ceragem; honoraria from Soterix Medical, outside the submitted work. Dr Andre Brunoni has nothing to disclose. Dr Leigh Charvet reports grants or contracts from Duke University, National MS Society, NIH NIBIB, NIH/NIDA; consulting fees from Syntropic Medical, Soterix Medical; honoraria from Soterix Medical, Yonsei University College of Medicine; meeting/travel support from International Neuromodulation Society (INS); stock or stock options from Johnson & Johnson, outside the submitted work.