Participants' experience of approach bias modification training with transcranial Direct Current Stimulation as a combination treatment for binge eating disorder

Objective: This study explored participants' experience of approach bias modification training (ABM) with transcranial Direct Current Stimulation (tDCS) for binge eating disorder (BED) within a randomised controlled trial (RCT). A subset of participants who completed the RCT were interviewed to attain feedback on treatment experience and outcomes.

Method: 15 participants with BED who completed the RCT were recruited, using purposive sampling. Participants received six sessions of concurrent ABM training with either real or sham tDCS. Semi-structured interviews relating to study experience and treatment outcomes were conducted and data were analysed thematically.

Results: The combined ABM and tDCS intervention was deemed acceptable and worthwhile by participants interviewed across both intervention groups. Negative preconceptions of tDCS were an initial deterrent to study participation for some, yet the brain stimulation experience was found to be tolerable. Minor and transient sensations and side effects attributed to tDCS were reported by most participants during and after stimulation, in addition to less pleasant aspects of ABM training, with no significant adverse effects reported by interviewees. Positive outcomes were described by participants across both intervention groups, relating to changes in BED symptoms and to broader beneficial effects on associated cognitive and emotional factors. Two participants experienced a shift in autonomy, attributed to tDCS and the combined intervention respectively.

Conclusions: Adults with symptoms of BED found concurrent ABM and tDCS sessions to be acceptable, despite initial apprehension about the safety of tDCS. Findings are relevant to the neuroethics literature and may inform science communication strategies on neuromodulation treatments.