Acceptability of Home-Based Transcranial Direct Current Stimulation (tDCS) in Bipolar Depression: Thematic Analysis of Individual Views

Background: Acceptability is a multifaceted concept that reflects how a treatment is viewed, which impacts on patient engagement, adherence, and provider implementation. Transcranial direct current stimulation (tDCS) is emerging as a novel non-invasive treatment for bipolar depression. We developed a home-based protocol for tDCS which has demonstrated efficacy in unipolar and bipolar depression. We sought to explore the acceptability of home-based tDCS in bipolar depression. Methods: Participants were 35 (26 women) with bipolar disorder (mean age 47.37 years, SD ± 13.78) in a current depressive episode of at least moderate severity. tDCS was provided in a bifrontal montage 2 mA for 30 minutes in sessions over 6 weeks with real-time supervision. Acceptability was assessed in a questionnaire and individual interviews, conducted at two timepoints: baseline and post treatment. Individual interviews were analysed by thematic analysis. Results: Six main themes were found: helpfulness, side effects, burden, gratitude, ethicality and comparison to medications. The themes of gratitude and comparison with medications were novel in this group compared to unipolar depression. Conclusion: Themes reflected high acceptability of tDCS treatment in bipolar depression and indicated strong interest in novel treatments in this population. Qualitative analysis can provide novel insights into individual experiences, understanding barriers to treatment, and offer guidance for improving clinical treatments. Trial registration: ClinicalTrials.gov: NCT05436613 registered on 23 June 2022 https//www.clinicaltrials.gov/study/NCT05436613.