Addressing self-criticism in depression using CBT-based emotion-focused chairwork: study protocol of a randomised controlled trial

Abstract

Introduction

Self-criticism is a key feature in people diagnosed with depression, resulting in significant psychological distress. Despite the fact that cognitive–behavioural treatments are readily available, a significant number of patients report experiencing cognitive, but not emotional, change following therapy, resulting in the maintenance of psychological symptoms. Additionally, interventions targeting emotional experiencing, such as chairwork, are generally implemented within large-scale therapeutic treatments. Therefore, within the present study, we aim to evaluate the efficacy and safety of a short intervention using emotion-focused chairwork to target self-criticism in patients diagnosed with depression.

Methods and analysis

The study is designed as a randomised controlled trial with two parallel arms. 62 patients diagnosed with depression will be randomised to the intervention group or the waiting-list control group receiving treatment as usual. The intervention comprises of three treatment sessions using the chairwork technique over the course of 3 weeks. Outcome assessments will take place 1 week before the first treatment session, as well as 1 week and 3 months after the last treatment session. The primary outcomes are self-criticism and self-compassion. Secondary outcomes assess depressive symptoms, emotion regulation and overall self-esteem. Statistical analysis will be performed using intention-to-treat analysis, as well as per-protocol analysis implementing linear-mixed models.

Ethics and dissemination

The study was approved by the Ethics Committee of the State Chamber of Physicians in Baden-Wuerttemberg, Germany (approval number: F-2023-12). Scientific findings shall be published in peer-reviewed journals to inform prospective clinical studies focusing on the implementation of chairwork within clinical practice.

Trial registration number

German Clinical Trials Register (DRKS00031307; https://drks.de/search/de/trial/DRKS00031307).

STRENGTHS AND LIMITATIONS OF THIS STUDY.

• Semistructured short-intervention using chairwork to target self-criticism.

• Follow-up assessment 3 months after treatment termination.

• Randomised controlled trial allowing for generalisability of results.

• Results may not transfer to inpatient treatment settings.

• Study does not include an active control group.

Introduction

Emotion-focused chairwork originates within psychodrama, where it has been invented by Moreno.¹ Later on, it has been extended and elaborated by Pearls, the founder of gestalt therapy.² Ever since, chairwork has been adapted and implemented within various psychotherapeutic stances, such as compassion-focused therapy³ or schema therapy (eg,^{4 5}), both of which originate within the third wave of cognitive–behavioural therapy (CBT). Overall, chairwork techniques follow a dialogical structure, signifying that different parts of the problem (outside and inside oneself) are being placed and re-enacted on various chairs (eg,^6–8). This experiential technique follows three overarching principles: (1) multiplicity (i.e., the self is multifaceted, and relevant parts of the self can be differentiated through placement in separate chairs); (2) embodiment and personification (i.e., the self-parts can be made ‘human-like’ through enactment by the patient, in order to facilitate exchange of information); and (3) dialogue (i.e., encouragement of the self-parts to speak to one another, to the patient or the therapist, in order to ameliorate distress and/or resolve conflicts (Pugh, p3).⁷

Within CBT, chairwork has been implemented to alter core beliefs,⁹ specifically when cognitive change occurs without alterations on an emotional level. This mechanism appears particularly important considering the notion that enhancement of emotional processing in patients with depression improves therapeutic outcomes.¹⁰ Moreover, chairwork has been used to resolve ambivalence (eg,^11–13), change distressing childhood memories (eg,^{14 15}), elicit high levels of affect in order to foster exposure and habituation (eg,^{15 16}), or reduce experiential avoidance.¹⁷ Within third-wave CBT, chairwork has been used to work with self-criticism,^{18 19} as well as with early maladaptive schemas.⁵ Working with self-criticism in clinical disorders might be particularly worthwhile within psychotherapeutic treatment due to several reasons: (1) self-criticism plays a central role within psychological distress and (2) within the majority of clinical disorders, and (3) is associated with poor treatment outcome.^{20 21}

Looking at scientific evidence for the efficacy of chairwork as a standalone treatment, there is a comparably small but promising amount of research indicating its efficacy. For example, de Oliveira and colleagues^{20 22} showed that a single-session trial-based chairwork has a significant impact in reducing negative core beliefs and accompanying emotions. Furthermore, within the same study, self-criticism was significantly reduced after treatment. Additionally, Shahar and colleagues demonstrated within a pilot study that the two-chair technique could effectively reduce symptoms of self-criticism and enhance self-compassion in a subclinical sample of participants displaying depressive and anxiety symptoms.²¹ The reported effect sizes were medium to large, with results being maintained at a 6-month follow-up. Moreover, the same technique has proven to reduce global distress, thought suppression, and rumination.^{23 24} Comparing short interventions using standardised cognitive interventions with chairwork interventions, preliminary findings indicate that chairwork is superior to cognitive restructuring in reducing fears of negative evaluation in socially anxious individuals.^{20 25 26} Lastly, a recent multiple baseline study by Stiegler and colleagues demonstrated a significant reduction in depression and anxiety symptoms after implementing five sessions of two-chair dialogue in a sample of people who are on paid sick leave.²⁷

However, despite these preliminary findings on the efficacy of chairwork, the presented studies include some major limitations: regarding the study design, naturalistic designs,²⁶ quasi-experimental designs^{21 23} and an additive component design²⁷ were used. One randomised controlled trial (RCT) implementing chairwork, however, the researchers did not solely administer the chairwork technique, but also other CBT-based cognitive interventions.²⁵ Furthermore, convenience samples²³ and subclinical samples²¹ were used, while studies investigating clinical samples did not implement structured diagnostic interviews to establish diagnosis.^{26 27} Lastly, the above-stated studies are characterised by small sample sizes. Therefore, the presented studies are limited in generalisability and reliability, necessitating RCTs including patients with verified clinical diagnosis and adequate sample sizes that allow for more accurate conclusions about the efficacy and safety of the chairwork technique. Based on the previous findings and research gaps, the present study aims to evaluate the efficacy and safety of a short-intervention using CBT-based chairwork for self-criticism in patients with depression. Doing so, various self-report measures on self-criticism, self-compassion, depressive symptoms, emotion regulation and self-esteem were implemented before and after treatment completion.

Methods

Study design

The study is designed as a randomised controlled superiority trial with two parallel arms, comparing a therapeutic treatment using chairwork with a waiting-list control group (WL), receiving treatment as usual. Patients within the therapeutic intervention will receive three sessions of chairwork-based psychotherapy, with each therapeutic session lasting approximately 90 min per week. Patients within both groups (i.e., intervention group and WL) will receive usual care, such as psychiatrist or primary physician visits. After termination of the last assessment session, patients within the WL group will receive the same treatment as patients previously assigned to the intervention arm.

Study setting

The study will be conducted at the Christophsbad Clinic, Goeppingen, Germany. The Christophsbad Clinic is a large psychiatric facility consisting of several inpatient units. Additionally, the same facility holds two psychiatric outpatient units, as well as two day units. Within both the inpatient and outpatient facilities, patients with a diagnosis of depression will be screened for eligibility during their ongoing treatment. After treatment termination, eligible patients will be invited for the diagnostic assessment (T0). Moreover, the study will be advertised through social media accounts and the web page of the Christophsbad Clinic. After an initial diagnostic assessment, patients will be randomly assigned to either the intervention or WL group. Patients within the intervention group will receive therapeutic treatment within one week after completing the diagnostic interview and assessment questionnaires. Patients within the WL group will be invited to receive the treatment sessions after study participation.

Participants and recruitment

Sixty-two adult patients (31 per group) with a primary diagnosis of depression will be recruited at the inpatient and outpatient facilities of the Christophsbad Clinic. Recruitment and screening for study participation will take place during inpatient or outpatient treatment, whereas patients will be contacted for study participation after treatment termination. Recruitment started on 18 May 2023 and will presumably be terminated in December 2024. Patients will be included if they fulfill eligibility requirements, provide written informed consent, and are willing to partake in the study. Patients will be included if they are at least 18 years old, fluent in written and spoken German, and fulfill diagnostic criteria for depression (International Statistical Classification of Diseases and Related Disorders (ICD-10) F32.0–F32.2; F33.0–F33.2). Exclusion criteria include current psychotherapeutic treatment, acute psychiatric medication (e.g., benzodiazepines), severe comorbid psychiatric disorders (e.g., psychotic disorder, bipolar disorder), acute suicidality, and substance abuse/dependence. Patients will be included if their psychopharmaceutical medication intake has been stable for at least 4 weeks. Depressive symptomatology will be assessed using the Structured Clinical Interview of the Diagnostic and Statistical Manual of Mental Disorders (DSM-V Axis I (SCID-I)).²⁸ Other comorbid Axis I diagnoses will be established using the Mini-International Neuropsychiatric Interview (MINI).^{29 30} Furthermore, Axis-II comorbidity will be assessed using the Structured Clinical Interview for DSM-V Axis II.³¹

After an initial screening for inclusion criteria (e.g., general symptoms of depression, age) and a short overview of study relevant information, patients will be invited to a diagnostic appointment where they will receive further information and provide written informed consent (see figure 1 for patient flow). Patients will receive a detailed oral description of the implemented chairwork technique and will be informed about possible risks and benefits. Additionally, they will receive an information sheet about chairwork as a reading assignment in between the diagnostic session and the first treatment appointment. Furthermore, during the diagnostic assessment (T0), eligibility criteria will be established as follows: depressive disorder using the SCID-I interview, German fluency by the patients’ ability to complete the interview and assessment questionnaires, other severe psychiatric disorders using the MINI, suicidality via the Columbia-Suicide Severity Rating Scale³² and current psychotherapeutic treatment, as well as psychiatric medication using a self-developed questionnaire (see table 1). Moreover, a chairwork interview intake form based on Pugh³³ and adapted by JK will be conducted to identify possible treatment targets, such as situations in which the patient was extremely self-critical, for the upcoming therapeutic sessions.

Figure 1.

CONSORT study flow chart. CONSORT, Consolidated Standards of Reporting Trials.

Table 1.

Enrolment, chairwork intervention and assessment schedule

Timeline	Screening	Diagnostics	Post-allocation
	−t1	t0	t1	Chairwork intervention	t2	t3
Eligibility screen	X
Informed consent		X
Demographics		X
MINI		X
SCID-I depression		X
SCID-II questionnaire		X
C-SSRS		X
Treatment information and chairwork information sheet		X
Chairwork intake interview		X
Allocation (post-diagnostics)		X
FSCRS			X		X	X
SCS			X		X	X
BDI-II			X		X	X
RSES			X		X	X
BSI			X		X	X
Treatment acceptability and patient satisfaction					X

BDI-II, Beck Depression Inventory-II; BSI, Beck Scale for Suicidal Ideation; C-SSRS, Columbia-Suicide Severity Rating Scale; FSCRS, Forms of Self-Criticizing/Reassuring Scale; MINI, Mini-International Neuropsychiatric Interview; RSES, Rosenberg Self-Esteem Scale; SCID-I, Structured Clinical Interview for DSM-V Axis I; SCID-II, Structured Clinical Interview for DSM-V Axis II; SCS, Self-Compassion Scale; t₀, diagnostic assessment; −t₁, eligibility screening; t₁, assessment time point 1; t₂, assessment time point 2; t₃, assessment time point 3.

Randomization and allocation concealment

Patient randomisation to either the intervention or WL group will be established using an allocation sequence generated by an independent researcher (JK), who was not involved within study recruitment and assessment, implementing a true randomisation process (random.org). A variable block length was used, to prevent psychologists involved within either recruitment or assessment from predicting the allocation sequence. After creating the allocation sequence, sealed envelopes containing the allocation for each participant will be numbered (JK) and handed to the participant after completion of the diagnostic interview and questionnaire assessments, to assure allocation concealment. After this time point, neither the assessor, nor the clinical psychologist (JM), nor the patient will be blind about treatment allocation, as only the intervention group will receive immediate psychotherapeutic treatment conducted by the clinical psychologist (JM), whereas the WL group will receive all treatment sessions after completion of the last assessment time point.

Intervention

The implemented semistructured cognitive–behavioural chairwork intervention is based on Pugh³⁴ and comprises of three treatment sessions over the course of 3 consecutive weeks, with a duration of approximately 90 min per session. Upon arrival to the laboratory, the chairwork intake form will be jointly reviewed with the patient, and possible complaints surrounding self-criticism, I-positions related to the complaint, as well as dialogical dysfunctions, will be identified. During this stage, the patient is encouraged to summarise their complaint and their goal for the therapeutic session. The psychologist will then create a dialogical hypothesis based on the intake form and the patients’ reported complaint, and will proceed to describe and model the chairwork technique. Thereinafter, the concept of centre will be described, by explaining that the client’s original chair will function as a safe and non-active location, where the patient can build self-awareness and (re)integrate I-positions.

After this initial introduction, the active stage of the chairwork session will commence. First, the patient will be asked about any concerns surrounding the chairwork technique. If the patient holds reservations, a dialogical chairwork will be implemented working with the inner protector.³⁴ Thereinafter, a short diagnostic chairwork enactment, where the therapist will interview the I-positions, will be conducted as a warm-up, and to test the dialogical hypothesis generated. Ultimately, the discussed problem will be enacted by placing the patient onto two distinct chairs, whereas the two chairs represent conflicting I-positions, which will enter into a dialogue performed by the patient. This process will be structured and supported by the clinical psychologist. After this sequence, the patient will be invited to witness the enactment by standing up with the therapist. This position represents a more distant, compassionate observer, who will reflect the experienced chairwork process together with the psychologist. Thereinafter, the patient will be instructed to sit back onto his initial chair (=centre), summarise the session and develop important take-home messages as well as lessons learnt, which will be audio-recorded using the patient’s mobile phone. Afterwards, one to two problem solutions including steps to be taken towards solving the problem will be noted on a self-developed diary card to assure transfer to everyday life. Lastly, if there is any time remaining, the psychologist will conduct a role-play, where the psychologist performs the role of the problem or old solution, and the patient represents the role of the newly invented solution.

The upcoming treatment sessions two and three will begin by reviewing the diary card. The diary card assesses difficult situations, which arose since the last treatment session. Additionally, within the diary card, the patient is instructed to identify critical I-positions, and reflect on adaptive and maladaptive behaviours surrounding the situation. Lastly, the patient is prompted to develop initial ideas around functional problem-solving. After reviewing the diary card, the clinical psychologist will reflect on and summarise the previous therapy session with the patient and identify any open questions or problems. On the basis of the diary card and the review of the past session, a problem area will be identified and treated with the chairwork technique described within the previous paragraph. After session two, the patient will again receive an audio-recording, as well as a diary card for the upcoming week.

Outcome assessment

The study schedule is described in table 1. Patient assessment will take place at the following time points: baseline (T1; after completion of the diagnostic interview, ~1 week before the first treatment session), post-intervention (T2; ~1 week after last treatment session), follow-up (T3; 3 months after last treatment session). All assessments, apart from the diagnostic interview, will be conducted using a certified scientific online platform (SoSciSurvey), whereas patients will be able to conveniently complete assessments from home. Upon survey completion, data will be automatically transferred to the clinical psychologist (JM) by email. Patients will be reminded to complete assessment sessions by automatically generated emails. If the assessments are not completed within the described time frame, the clinical psychologist will additionally remind the patients by phone and/or email. All outcome measurements are validated German versions of the respective questionnaires.

Primary outcomes

The primary outcomes include assessments self-criticism and self-compassion.

Forms of Self-Criticizing/Reassuring Scale³⁵ is a 22-item self-report measurement evaluating self-criticism and self-reassuring tendencies. Within the measurement, two types of self-criticism are assessed: feeling of inadequacy, and hating and wanting to hurt the self. The measurement has excellent internal consistency, ranging between 0.86 and 0.90 for the two subscales.³⁵

Self-Compassion Scale³⁶ is a 26-item self-report questionnaire assessing various aspects of self-compassion. Therefore, the scale consists of six subscales evaluating self-kindness, mindfulness, self-judgement, overidentification, isolation and common humanity. Moreover, an overall score can be calculated. The measurement has good internal consistency (Cronbach’s α=0.86³⁷).

Secondary outcomes

Secondary outcomes will be negative affectivity, emotion regulation and self-esteem.

Beck Depression Inventory-II (BDI-II).³⁸ The BDI-II will be used to measure symptoms of negative affectivity and depression. The self-report questionnaire comprises of 21 items, which assess symptoms associated with negative mood and affect. The questionnaire has good internal consistency (Cronbach’s α=0.84–0.90³⁹).

Emotion Regulation (SEK-27).⁴⁰ The SEK-27 is a 27-item measurement designed to assess various aspects of emotion regulation. Hence, the questionnaire consists of nine subscales evaluating clarity, body perception, acceptance, attention, understanding, willingness to confront oneself with one’s emotions, regulation, resilience and self-support. Moreover, an overall subscale can be built. The measurement has good internal consistency (Cronbach’s α=0.93⁴⁰).

Rosenberg Self-Esteem Scale (RSES).⁴¹ The RSES is a 10-item measurement assessing self-esteem. It consists of five positively and five negatively formulated items, which form an overall score. The measurement has good internal consistency (Cronbach’s α=0.88⁴²).

Acceptability and patient satisfaction

A self-developed nine-item questionnaire using Visual Analogue Scales will be used to assess treatment acceptability and satisfaction (e.g., ‘I feel like I was able to benefit from the treatment’, ‘I would recommend this treatment to others with similar problems’).

Monitoring for adverse events

Adverse events will be monitored using the Beck Scale for Suicidal Ideation.⁴³ This 21-item self-report questionnaire assesses suicide risk. The measurement includes assessments for suicidal thoughts, ideation, planning, as well as various aspects of attempting suicide. It will be administered at all assessment time points (T1–T3). The first five questions within the questionnaire serve as a screening for suicidality. If patients mark a value of two on question number four and/or five, they will be contacted by the clinical psychologist for further evaluation. Additionally, the clinical psychologist’s contact information, as well as other important emergency phone numbers (e.g., number of the inpatient clinic, crisis hotline), will be handed to all partaking patients during the diagnostic interview. If a patient is termed at risk of suicide during any contact with the clinical psychologist, a referral for further care will be initiated (e.g., to the psychiatric inpatient facility). Other adverse events include but are not limited to: worsening of depressive symptoms (BDI-II), terminating study participation due to self-reported adverse effects of the treatment sessions (acceptability and patent satisfaction questionnaire) or admission to an inpatient unit. Adverse events will be critically evaluated within the study management group (JK, ZS-V and JM). Within this context, the group will discuss the relationship of the adverse event and the implemented chairwork treatment (0=not all related, to 3=definitely related).

Trial management and monitoring

The principal investigators (JK and ZS-V) are primarily responsible for study implementation. The oversight and management of the described study will be accomplished by bi-weekly meetings between the clinical psychologist (JM), the assessors, and the primary investigators. The clinical psychologist is a licensed and experienced cognitive–behavioural psychotherapist, who received extensive training conducting chairwork (JM). Furthermore, both supervisors (JK and ZS-V) are experienced, licensed cognitive–behavioural psychotherapists, whereas JK is also a licensed schema therapist. Due to the size and nature of the current study, a data monitoring committee was non-essential.

Data collection and management

Data will be collected during each of the assessment time points (T1–T3) via an online platform (SoSciSurvey) and automatically transferred to the clinical psychologist (JM). Each patient will receive a pseudonymised ID during the diagnostic assessment, which will be communicated with the patient and used to connect all collected data (T0–T3) to the respective patient. Upon receiving the pseudonymised dataset, the clinical psychologist will continuously store all collected data on an electronic database. Data will be regularly transferred to a remote server to assure data retention. No identifiable information about the partaking patients will be held within the electronic database. This information will be stored in a separate, password-protected electronic file and accessed as needed prior to data analysis. Access to this data will be solely granted to members within the research team.

Patient and public involvement

Patients and/or the public were not involved.

Sample size and data analysis

Previous studies implementing short interventions using chairwork within highly self-critical individuals²¹ or other forms of emotion-focused short interventions such as imagery rescripting within clinical samples^{44 45} found medium to large effect sizes ranging between d=0.72 and d=2.0. Based on a power of 1−ß=0.95, a medium effect size (f²=0.61) and a significance level of α=0.05, using F-tests (multivariate analysis of variance), a sample size of N=52 (26 per group) will be needed. Adding a dropout rate of approximately 20%, we will include a total of N=62 patients (31 per group) for the overall sample. To reduce overall dropout rates, patients will be contacted by phone or emails by the clinical psychologist if they do not complete the questionnaire assessments (T1–T3) within due course.

Data analysis will be conducted using SPSS (V.28) and R, implementing intention-to-treat, as well as per-protocol analysis. Linear mixed models will be computed to draw accurate conclusions about patients displaying missing data. Specifically, a repeated measures mixed-model design including analysis of variance across all time points (T1–T3) will be used, in order to assess within-effect and between-effect sizes (Hedge’s g), as well as contrasts. To evaluate between-group differences at baseline, t-tests, as well as X² tests, will be conducted as appropriate. If significant differences are found, variables will be subsequently included as covariates.

Ethics and dissemination

The Ethics Committee of the State Chamber of Physicians of Baden-Wuerttemberg, Germany (approval number: F-2023-12) approved the final study. Central ethical considerations include informed consent procedures, involvement of a WL control group, as well as the utilisation of emotion-focused chairwork within the treatment sessions. Participants will provide written informed consent prior to study participation. Doing so, all patients receive oral and written information about the extent of the research project, the included intervention techniques and associated risks, data protection measures and about the ability to withdraw from study participation without any further consequences at any time of the study. The study duration will be about 4 months. During this period, neither participants within the intervention nor patients within the WL group will be able to receive psychotherapeutic treatment outside of the study, in order to avoid confounding effects. However, considering that waiting times for receiving outpatient psychotherapeutic care are around 3–9 months,⁴⁶ patients within this study are not disproportionally disadvantaged: as study inclusion usually takes place immediately after inpatient treatment termination, it is unlikely that any of the included patients would be able to receive outpatient care within the study time frame. Nevertheless, all included patients are allowed to schedule appointments with their primary physician or psychiatrist. Regarding the implemented emotion-focused chairwork interventions, we expect an increase in negative emotions during the sessions; however, these will be positively resolved at the end of each therapeutic treatment. As the chairwork technique has been regularly implemented within various large-scale therapeutic treatments,^{4 47 48} without reports of long-term adverse effects, we do not expect symptom exacerbation.

Scientific findings resulting from the here presented study will be published in peer-reviewed journals. Furthermore, key results will be presented at national and international scientific conferences. Lastly, data collected within the current project will be analysed and published within a doctoral thesis. The dataset used and/or analysed during the current study will be available from the corresponding author upon reasonable request. If our hypotheses are confirmed, funding will be sought to conduct larger-scale RCTs, involving a variety of clinical diagnoses and transdiagnostic clinical populations, as well as different clinical settings (i.e., inpatient and outpatient), and treatment formats (i.e., stand-alone treatment or add-on treatment).

Discussion

The present study aims to examine the efficacy and safety of a short intervention using CBT-based chairwork for self-criticism in patients with depression in order to better understand the functionality of specific treatment techniques for targeted psychological symptoms. We will evaluate how three sessions of CBT-based chairwork will reduce psychological symptoms. Specifically, we assume that the intervention will decrease self-criticism and depressiveness, and increase self-compassion, adaptive emotion regulation and self-esteem, as past research has shown initial evidence for decreased levels of self-criticism and depressiveness, and an increase of self-compassion in subclinical patients after psychological treatment using chairwork. The findings of this study will help us to determine if CBT-based chairwork implemented as a short-intervention can be a useful tool in treating targeted symptoms associated with depression. Such knowledge of the safety and efficacy of targeted short-interventions will be helpful to inform intervention strategies which can be used to alleviate psychological distress while waiting for long-term psychological inpatient or outpatient treatment. Furthermore, by increasing the knowledge around specific interventions for specific psychological symptoms (i.e., which for what), treatment durations could be decreased.

The study has several strengths. First, we used a semi-structured short-intervention that allows for high treatment replicability. Second, we implemented an RCT to allow for the generalisability of the treatment outcomes. Third, we implemented a 3-month follow-up period to assess long-term treatment outcomes. Nevertheless, the study also presents some limitations. Within the current intervention, we implemented an outpatient setting; thus, results might not transfer to inpatient treatments. Furthermore, blinding of the patients regarding the treatment condition was not possible, as our study did not include an active control group. Therefore, other factors, such as patients’ expectations or the therapist–patient relationship, should be considered when interpreting results.

Protocol amendments

Substantial protocol amendments will be indicated within the clinical trials register, and will be stated within publications associated with the evaluated data.

Ethics statements

Patient consent for publication

Obtained.