A Study of Home-use Brain Stimulation to Treat Bipolar Depression (BDEP)

Home-based Transcranial Direct Current Stimulation in Bipolar Depression: a Randomised, Double-blind, Placebo-controlled Trial

Bipolar depression is a long-lasting and disabling condition, and many people continue to experience depressive symptoms despite standard treatments. Transcranial direct current stimulation (tDCS) is a non-invasive form of brain stimulation that uses a very small electrical current applied through the scalp and has shown promise as a treatment for depression. This study aims to find out whether a home-based tDCS device is effective and safe in reducing symptoms of bipolar depression when compared with a placebo (sham) treatment. The study will also look at how acceptable the treatment is to participants and how well people are able to use the device at home.

Who can participate? Adult patients aged 18 years and over who have a diagnosis of bipolar disorder and are currently experiencing a depressive episode.

What does the study involve? Participants must meet specific eligibility criteria, which will be assessed by the research team. People who do not meet the study criteria or for whom tDCS is not suitable will not be able to take part. Participants will be randomly assigned to receive either active tDCS or a placebo (sham) treatment. Neither the participant nor the researchers assessing outcomes will know which treatment has been assigned.

Participants will use a study device at home over a defined treatment period and will complete a series of assessments at set time points. These include clinician-rated interviews and self-reported questionnaires about mood and well-being. Device use and adherence data will be collected electronically. Participants will also be monitored for any side effects throughout their involvement in the study.

Although the study is multi-site, participation is primarily remote, with most study activities completed from the participant's home.

What are the possible benefits and risks of participating? Participants may experience an improvement in depressive symptoms. Information gained from this study may help improve future treatments for bipolar depression.

tDCS is generally well tolerated. Possible side effects include mild and temporary sensations such as tingling, itching, headache, or skin irritation at the electrode sites. All participants will be monitored for adverse events, and appropriate support will be available if needed.

Where is the study run from? The study is run from King's College London in collaboration with NHS research sites across the UK.

When is the study starting and how long is it expected to run for? April 2026 to October 2027

Who is funding the study? The National Institute for Health and Care Research (NIHR), UK.

Who is the main contact? Professor Cynthia Fu, the Chief Investigator at King's College London, cynthia.fu@kcl.ac.uk

Study Overview

• Status: Recruiting
• Conditions: Bipolar Disorder (BD)
• Intervention / Treatment: Device: Flow FL-100 tDCS headset

• Study Type: Interventional
• Enrollment (Estimated): 212
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Professor Cynthia Fu; Phone Number: 0207848832; Email: cynthia.fu@kcl.ac.uk

Study Locations

• United Kingdom
  • London, United Kingdom
    • Recruiting
    • South London and Maudsley NHS Foundation Trust
    • Contact: Oluwatofunmi Olaniyan; Phone Number: +44 20 7848 8326; Email: oluwatofunmi.olaniyan@kcl.ac.uk

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Adults aged 18 years or over.
2. Diagnosis bipolar disorder in a current depressive episode based on Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria assessed by structured clinical assessment, Mini-International Neuropsychiatric Interview (MINI) (Sheehan et al.,1998).
3. Having at least a moderate severity of depressive symptoms as measured by a score of at least 18 in MADRS (Montgomery and Åsberg, 1979).
4. Either not taking antidepressant medication or taking a stable dose of antidepressant medication for at least 6 weeks before enrolment.
5. Either not currently in psychotherapy or in ongoing psychotherapy for at least 6 weeks before enrolment.
6. Being under care of GP.
7. Agreeable for GP to be regularly informed by research team about participation.
8. Able to provide written, informed consent.

Exclusion Criteria:

1. Significant suicide risk as measured by answering 'yes' to questions 4, 5 or 6 on the Columbia Suicide Severity Rating Scale (C-SSRS) Screen (Posner et al., 2011).
2. Primary comorbid psychiatric disorder (e.g. obsessive compulsive disorder) based on DSM criteria as assessed in MINI (Sheehan et al., 1998).
3. Having a Young Mania Rating Scale (Young et al., 1978) score of 20 or more.
4. Current daily use of medications that affect cortical excitability (e.g. benzodiazepines).
5. Current illicit drug use or heavy alcohol use with high risk of alcohol use disorder as measured by a score of > 8 in Alcohol use disorders identification test consumption (AUDITC) (Khadlesari et al., 2017; NICE, 2023).
6. History of electroconvulsive therapy (ECT), transcranial magnetic stimulation (TMS), cranial electrotherapy stimulation (CES), transcranial direct current stimulation (tDCS), deep brain stimulation (DBS), other brain stimulation, or psychosurgery for depression.
7. History of esketamine / ketamine for treatment of depression.
8. Medical disorder that may mimic mood disorder (e.g. hormonal disorder).
9. History of myocardial infarction, coronary artery bypass graft (CABG), coronary heart failure (CHF), or history of other cardiac issues.
10. Have cognitive impairment (e.g. dementia).
11. History of a neurological disorder (e.g., cerebrovascular events, stroke, structural lesion, epilepsy, seizures, Parkinson's disease).
12. History of migraines or intractable headaches.
13. Implant in brain, neurocranial defect or active implantable medical device.
14. Shrapnel or any ferromagnetic material in head.
15. If female and of child-bearing potential, currently pregnant or planning to become pregnant during the study
16. Concurrent enrolment in another interventional study.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Sham Comparator: Sham tDCS + Treatment as Usual	Device: Flow FL-100 tDCS headset; The Flow FL-100 tDCS device is an adjustable headset with the electrodes built in. It delivers low-intensity direct current through scalp electrodes, modulating cortical excitability in the dorsolateral prefrontal cortex (DLPFC). The device is portable and commercially available.
Active Comparator: Active tDCS + Treatment as Usual	Device: Flow FL-100 tDCS headset; The Flow FL-100 tDCS device is an adjustable headset with the electrodes built in. It delivers low-intensity direct current through scalp electrodes, modulating cortical excitability in the dorsolateral prefrontal cortex (DLPFC). The device is portable and commercially available.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
To determine clinical efficacy of a 10-week course of home-based tDCS for bipolar depression in terms of depressive symptoms as measured by clinician-rated MADRS score in active and sham treatment arms at week 10	From randomisation to the end of treatment at 10 weeks

Secondary Outcome Measures

Outcome Measure	Time Frame
To assess effects in self-rated depressive symptoms following 10-week course of home-based tDCS between active and sham treatment arms as measured by Quick Inventory of Depressive Symptomatology (QIDS-SR)	From randomisation to the end of treatment at 10 weeks
To assess effects in clinician-rated anxiety symptoms following 10-week course of home based tDCS between active and sham treatment arms as measured by Hamilton Anxiety Rating Scale (HAMA)	From randomisation to the end of treatment at 10 weeks
To assess effects in self-rated anxiety symptoms following 10-week course of home-based tDCS between active and sham treatment arms as measured by Generalized Anxiety Disorder questionnaire (GAD-7)	From randomisation to the end of treatment at 10 weeks
To assess effects in self-rated quality of life following 10-week course of home-based tDCS between active and sham treatment arms as measured by EQ-5D-5L questionnaire	From randomisation to the end of treatment at 10 weeks
To assess effects in clinician-rated depressive symptoms at 6-month follow up between active and sham treatment arms as measured by clinician-rated MADRS	6 months post randomisation
To assess effects in self-rated depressive symptoms at 6-month follow up between active and sham treatment arms as measured by QIDS-SR	6 months post randomisation
To assess effects in clinician-rated anxiety symptoms at 6-month follow up between active and sham treatment arms as measured by HAMA	6 months post randomisation
To assess effects in self-rated anxiety symptoms at 6-month follow up between active and sham treatment arms as measured by GAD-7	6 months post randomisation
To assess effects in quality of life at 6-month follow up between active and sham treatment arms as measured by EQ-5D-5L	6 months post randomisation

Collaborators and Investigators

• Sponsor: King's College London
• Collaborators: South London and Maudsley NHS Foundation Trust

Publications and helpful links

General Publications

• Lagerberg PJ, Woodham RD, Selvaraj S, Lajmi N, Hobday H, Sheehan G, Ghazi-Noori AR, Rizvi M, Kwon SS, Orhii P, Machado-Vieira R, Soares JC, Young AH, Fidalgo AR, Rezaei H, Fu CHY. Acceptability of active and sham home-based transcranial direct current stimulation in major depression: mixed methods qualitative analysis in a randomised controlled trial. Ann Gen Psychiatry. 2025 Dec 4. doi: 10.1186/s12991-025-00607-4.
• Rezaei H, Woodham RD, Ghazi-Noori AR, Ritter P, Bauer M, Young AH, Bramon E, Fu CHY. Acceptability of Home-Based Transcranial Direct Current Stimulation (tDCS) in Bipolar Depression: Thematic Analysis of Individual Views. BMC Psychiatry. 2025 May 26;25(1):549. doi: 10.1186/s12888-025-06948-4.
• Ghazi-Noori AR, Woodham RD, Rezaei H, Sharif MS, Bramon E, Ritter P, Bauer M, Young AH, Fu CHY. Home-based transcranial direct current stimulation in bipolar depression: an open-label treatment study of clinical outcomes, acceptability and adverse events. Int J Bipolar Disord. 2024 Aug 20;12(1):30. doi: 10.1186/s40345-024-00352-9.
• Woodham RD, Selvaraj S, Lajmi N, Hobday H, Sheehan G, Ghazi-Noori AR, Lagerberg PJ, Machado-Vieira R, Soares JC, Young AH, Fu CHY. Home-based transcranial direct current stimulation for major depressive disorder: 6-month follow-up from randomised sham-controlled trial and open-label treatment phases. J Psychiatr Res. 2025 Jun;186:23-32. doi: 10.1016/j.jpsychires.2025.03.047.
• Woodham RD, Selvaraj S, Lajmi N, Hobday H, Sheehan G, Ghazi-Noori AR, Lagerberg PJ, Rizvi M, Kwon SS, Orhii P, Maislin D, Hernandez L, Machado-Vieira R, Soares JC, Young AH, Fu CHY. Home-based transcranial direct current stimulation treatment for major depressive disorder: a fully remote phase 2 randomized sham-controlled trial. Nat Med. 2025 Jan;31(1):87-95. doi: 10.1038/s41591-024-03305-y.
• Woodham RD, Rimmer RM, Young AH, Fu CHY. Adjunctive home-based transcranial direct current stimulation treatment for major depression with real-time remote supervision: An open-label, single-arm feasibility study with long term outcomes. J Psychiatr Res. 2022 Sep;153:197-205. doi: 10.1016/j.jpsychires.2022.07.026.

Study record dates

Study Major Dates

• Study Start (Estimated): April 24, 2026
• Primary Completion (Estimated): April 30, 2027
• Study Completion (Estimated): November 30, 2027

Study Registration Dates

• First Submitted: April 22, 2026
• First Submitted That Met QC Criteria: April 22, 2026
• First Posted (Actual): April 29, 2026

Study Record Updates

• Last Update Posted (Actual): April 29, 2026
• Last Update Submitted That Met QC Criteria: April 22, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Bipolar and Related Disorders; Mental Disorders; Mood Disorders; Bipolar Disorder
• Other Study ID Numbers: IRAS 348113; NIHR167361 (Other Grant/Funding Number: National Institute for Health and Care Research)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Deidentified individual participant data and the data dictionary will be made available on request to academic researchers. The Statistical Analysis Plan is available in the Supplementary Materials. A data request and brief analysis plan will be required in accordance with Ethics Committee requirements. These will be reviewed by the lead, study steering committee and study sponsor. A data transfer agreement (DTA) will have to be completed prior to any data being shared. Following completion of the DTA, data will be shared as password-protected files. Data sharing will abide by the rules and policies defined by the sponsor, relevant institutional review boards, and local, state and federal laws and regulations. Rights and privacy of individuals participating in the research will be protected at all times. Approval will not be provided for commercial use of the data.
• IPD Sharing Supporting Information Type: SAP

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No