Home-Based tDCS for Depression in BPD

"Description:~Participants randomized to this arm will receive 14 sessions of home-based transcranial Direct Current Stimulation (tDCS), administered twice daily for 30 minutes over 7 consecutive days. Each session will use a 2mA current with a SNAPstrap™ montage targeting the left dorsolateral prefrontal cortex (F3) with the anode and the right DLPFC (F4) with the cathode. Sessions include a 30-second ramp-up and ramp-down. The total delivered charge will be 48 coulombs.~Enhancement component:~Each session will be paired with cognitive and emotional enhancement strategies:~Emotion regulation script (DBT-inspired, personalized and pre-written based on a moderately dysregulated situation).~Cognitive training via Lumosity, targeting executive functions and memory."

"Description:~Throughout the study, participants are required to maintain stable pharmacological and psychotherapeutic regimens, defined as:~No changes in medications or therapy for at least 6 weeks after tDCS initiation.~TAU is provided by participants' regular treating physician or mental health professional, independent of the study team.~TAU includes psychotropic medication, psychotherapy, and case management, as clinically indicated."

"All participants receive access to a structured online psychoeducation program before randomization.~This includes:~* Short videos (8-14 minutes each) covering BPD, depression, neuromodulation, therapeutic success factors, and tDCS.~* Multiple-choice quizzes (MCQs) to ensure comprehension.~* Delivered in French with English subtitles. Designed to improve understanding of BPD and associated treatments, including the rationale for tDCS."

"Description:~Participants randomized to this arm will receive 14 sessions of sham tDCS, with identical scheduling and device setup as the active condition. The session mimics real tDCS (same SNAPstrap montage, ramp-up and ramp-down of 30 seconds), but no current is delivered after the initial 30 seconds.~Enhancement component:~Participants follow the same emotional regulation script and Lumosity cognitive training during"