A Relation Between Craving Induction and Treatment Response in Deep Transcranial Magnetic Stimulation (dTMS) for Reducing Antipsychotic-induced Weight Gain in Schizophrenia

Overview

Antipsychotic-induced metabolic disturbances, especially weight gain, are common in patients with schizophrenia. Furthermore, it is reported significant changes in food intake happened in patients with weight gain after intaking antipsychotics. There are no hitherto effective treatments for reducing antipsychotic-induced weight gain. dTMS which is a safe and non-invasive physical treatment indicates greater efficacy than other transcranial magnetic stimulation (TMS) by some research. Apart from that, symptom provocation is believed to improve the clinical responses to TMS. In this study, the investigators, firstly, evaluate the safety and effectiveness of dTMS for reducing antipsychotic-induced weight gain and secondly, unveil whether symptom provocation can affect the clinical responses to TMS.

The underlying causes of antipsychotic-induced weight gain are still unknown. Some research point out that it has something to do with metabolic disturbances and changes in appetite and food intake. With fMRI study, it is reported having dysfunction between prefrontal and insula cortex of its cognitive regulation, interoceptive signals and reward control. dTMS, H4 coil in particular, simultaneously targets prefrontal and insula cortex. Previous study has been deconstrued that dTMS could significantly improve weight gain. Moreover, it is reckoned that TMS has state-dependent effects on brain circuitry, suspected that symptom provocation may be made it more susceptible to modulation which may improve response. Therefore, this study is to explore the efficacy of dTMS on antipsychotic-induced appetite, and whether provoking symptoms can improve dTMS clinical responses. With regard to investigate this, the investigators will be carried out a randomized single session dTMS, crossover, sham controlled clinical trial. 30 Patients with schizophrenia will be randomly treated with dTMS after food cue induced craving (FCC), dTMS without FCC and sham condition without FCC. Each session has three days intervals for washout. The follow-ups are at the baseline and after each session immediately. The main outcome measures include the change in Food-Cravings Questionnaires state (FCQ-S) score, Visual Analogue Scale (VAS) score, changes in Stop-Signal test (SST) behavioral assessment and the resting-state functional magnetic resonance imaging data.