Effects of intermittent theta burst stimulation (iTBS) on appetite change and body weight in inpatients with schizophrenia in China: study protocol for a randomised controlled trial.

Abstract

Antipsychotics are likely to cause weight gain owing to increased appetite and other metabolic disturbances in patients with schizophrenia on prolonged medication. Conventional high-frequency repetitive transcranial magnetic stimulation has been employed to treat people with obesity and has shown certain effectiveness. The goal of this clinical trial is to evaluate the efficacy of intermittent theta burst stimulation (iTBS) in ameliorating appetite increase and weight gain induced by antipsychotics in patients with schizophrenia. In this randomised, double-blind, sham-controlled trial, 60 participants will be enrolled and allocated (1:1) to receive active or sham iTBS on the dorsolateral prefrontal cortex for 5 consecutive days. Appetite, body mass index, clinical symptoms, cognitive function and laboratory indicators will be assessed at baseline, after 5 days of treatments, and at 2 weeks and 4 weeks after all treatments. MRI examination will be conducted to detect brain structure, perfusion and functional connectivity. Data analysis will be conducted in a modified intention-to-treat population. The results of the study will provide evidence on the effectiveness and feasibility of iTBS in improving increased appetite induced by antipsychotics and explore the underlying neuroendocrine pathway affected by the intervention. The primary objective is to evaluate the efficacy of iTBS in weight gain in patients with schizophrenia taking antipsychotics. The secondary objective is to identify the neuroendocrine changes related to appetite in response to iTBS by assessing the variables of cognitive control, glucolipid metabolism and brain activity. The study protocol has been approved by the National Clinical Medical Research Center Ethics Committee of The Second People's Hospital of Dali Bai Autonomous Prefecture (no: 2023YN3) and The Second Xiangya Hospital (no: 2024K008). Written informed consent will be obtained voluntarily before enrolment. The results will be disseminated through publication in peer-reviewed journals and presentation at international conferences. NCT05783063.