Table 1.

General overview of potential forms of neuromodulation for the treatment of SUD.

Neuromodulatory technique	Invasive/Non-invasive	Target depth	Focal	FDA approved indications	Adverse events	Patient acceptability
Transcranial Magnetic Stimulation (TMS)	Non-Invasive	Cortical	No	Depression, OCD	Temporary pain, muscle twitch, very low seizure risk	Some forms (rTMS) require daily visits to a clinic for several weeks (though continuous theta burst stimulation treatment requires less treatment frequency/length).
Low Intensity Focused Ultrasound (LIFU)	Non-Invasive	Subcortical	Yes	Parkinson’s, Essential Tremor,	Limited, theoretical risk of ICH	Perceived as non-invasive by patients
Deep Brain Stimulation (DBS)	Highly Invasive	Subcortical	Yes	Parkinson’s, Essential Tremor, Dystonia, Epilepsy, OCD	Brain implant related side effects: pain, intracerebral hemorrhage, infection	Patient’s concern regarding brain implant and managing an implanted device
Transcranial Direct Current Stimulation (tDCS)	Non-Invasive	Cortical	No	None	Few side effects	Patients can self-manage at home
Vagus Nerve Stimulation (VNS)	Invasive (Implantable VNS)	Direct Nerve Stimulation	Yes	Depression, Epilepsy	Difficulty swallowing, vocal changes, shortness of breath	Patient’s concern regarding implant and managing an implanted device
Auricular Nerve Stimulator/Percutaneous Nerve Field Stimulation (PNFS)	Minimally Invasive/Non-Invasive	Direct Nerve Stimulation	No	Symptoms of Opioid withdrawal	Bleeding, pain, dermatitis	Minimally invasive wearable device, viewed as more acceptable by patients
Trigeminal Nerve Stimulation (TNS)	Non-invasive (eTNS)	Direct Nerve Stimulation	Yes	Pediatric ADHD	Drowsiness, increased appetite, sleep dysfunction, teeth clenching, headache, fatigue	Viewed as more acceptable due to non-invasiveness