Home-based transcranial direct current stimulation in bipolar depression: an open-label treatment study of clinical outcomes, acceptability and adverse events

Abstract

Current treatments for bipolar depression have limited effectiveness, tolerability and acceptability. Transcranial direct current stimulation (tDCS) is a novel non-invasive brain stimulation method that has demonstrated treatment efficacy for major depressive episodes. tDCS is portable, safe, and individuals like having sessions at home. We developed a home-based protocol with real-time remote supervision. In the present study, we have examined the clinical outcomes, acceptability and feasibility of home-based tDCS treatment in bipolar depression. Participants were 44 individuals with bipolar disorder (31 women), mean age 47.27 + 12.89 years, in current depressive episode of moderate to severe severity (mean Montgomery-Åsberg Depression Rating Scale (MADRS) score 24.59 + 2.64). tDCS was provided in a bilateral frontal montage, F3 anode, F4 cathode, 2mA, for 30 minutes, in a 6-week trial, for a total 21 sessions. Participants maintained their current treatment (psychotherapy, antidepressant or mood stabilising medication) or maintained being medication-free. A researcher was present by video call at each session. 93.2% participants (n=41) completed the 6-week treatment. There was a significant improvement in depressive symptoms following treatment (mean MADRS 8.77 + 5.37), the rate of clinical response was 77.3% (MADRS improvement of <=50% from baseline), and the rate of clinical remission was 47.7% (MADRS rating of <=9). Acceptability was endorsed as "very acceptable" or "quite acceptable" by all participants. No participants developed mania or hypomania. Due to the open-label design, efficacy findings are preliminary. In summary, home-based tDCS with real-time supervision was associated with significant clinical improvements and high acceptability in bipolar depression.