Depression is a prevalent and debilitating disorder. The most common treatments are antidepressant medications and talking therapies. However, for many individuals, these are not their treatment of choice. Furthermore, even following a full course of treatment with an antidepressant or talking therapy, over one third of patients continue to be unwell.

The novel brain stimulation treatment, transcranial direct current stimulation (tDCS), is a potential first-line treatment for major depression. The present research question is whether tDCS can be provided as a home-based treatment for major depression for adults with major depression.

The novel brain stimulation treatment, transcranial direct current stimulation (tDCS), is a potential first-line treatment for major depression. tDCS generates a small electric current which modulates how easy it is for active brain cells to discharge. The device is a neoprene cap worn over the head, and in the cap there are two electrodes, which are small metal discs, where the current comes from. tDCS does not directly stimulate brain cells to cause a seizure like electroconvulsive therapy (ECT) and it does not induce brain cells to discharge like transcranial magnetic stimulation (TMS).

Clinical studies have shown that tDCS treatment could help to improve the symptoms of depression. The main side effects have been redness, skin irritation or sensations (itching, tingling or burning) under the electrodes. Less commonly reported side effects include headache or tiredness. tDCS is a portable and safe treatment.

The studies to date have mostly looked at tDCS treatment which has been provided in a research setting. This is a problem because the treatment requires daily sessions for several weeks which could limit whether individuals would be able to go every day. As tDCS is a portable and safe treatment, it could be provided in the community.

The study research question is whether tDCS could be provided as a home-based treatment for major depression. The study will include adults with major depression.

Inclusion Criteria:

• diagnosis of major depressive disorder based on DSM-5 criteria
• minimum score of 16 on Hamilton Rating Scale for Depression (HAM-D)

Exclusion Criteria:

• history of treatment-resistant depression
• comorbid psychiatric disorder
• significant risk of suicide or self harm
• any contraindications to tDCS, including implanted electronic medical devices

Anonymised data will be made available on request.

Starting 6 months after publication

Individual access by request

Participants were asked about adverse events by researchers before and after every tDCS session for 6 weeks, then at 3 and 6 month follow-up visits. A total time frame of 7.5 months.

In addition to asking participants about adverse events at every tDCS session and at follow up, the tDCS adverse events questionnaire was completed weekly during the 6-week treatment period to record adverse events that participants felt were related to the tDCS. Reported adverse events are for all participants across the full 6-weeks of treatment and indicate how many participants experienced the adverse event and how many times in total each adverse event was reported.

Due to the open-label design, there was no sham treatment arm and all participants received the active tDCS treatment.

Real-time supervision at each session may have contributed to symptom improvement.

As the protocol was not designed to establish efficacy, the findings should be considered as preliminary, and a placebo sham treatment control group is required to investigate efficacy.