Enhancing the outcomes of bariatric surgery with inhibitory control training, electrical brain stimulation and psychosocial aftercare: a pilot study protocol

Notwithstanding the documented short- and long-term weight loss and remission of physical and mental diseases following bariatric surgery, a significant proportion of patients fail to respond (fully) to treatment in terms of physical and mental health improvement. Mounting evidence links food-specific impulsivity, prefrontal cortex (PFC) hypoactivity and disrupted hormone secretion in bariatric surgery candidates to poorer post-surgical health outcomes. Neuromodulatory treatments like transcranial direct current stimulation (tDCS) uniquely target these neurobehavioral impairments. We present a pilot study protocol offering tDCS combined with an inhibitory control training and a structured psychosocial intervention to patients after bariatric surgery.

A total of N = 20 patients are randomized to 6 sessions of verum or sham tDCS over the PFC, combined with an individualized food-specific inhibitory control training and a structured psychosocial intervention within 18 months after bariatric surgery (t0). Beyond acceptability, feasibility and satisfaction of the intervention, effects of verum versus sham tDCS on food-specific impulsivity and on secondary outcomes quality of life, general impulsivity and psychopathology, food-related cravings, eating disorder psychopathology, weight trajectory and endocrine markers are assessed 4 weeks (t1) and 3 months after the intervention (t2).

Results will provide information on the potential of combining tDCS with an inhibitory control training and a structured psychosocial intervention to enhance physical and mental outcomes after bariatric surgery. The present study may guide the development of future research with regard to tDCS as a brain-based intervention and of future post-surgical clinical programs, paving the way for randomized-controlled trials in larger samples.

The trial was prospectively registered on July 8, 2024, under the registration number DRKS00034620 in the German Clinical Trials Register (https://drks.de/search/de/trial/DRKS00034620).