Impact of neuroregulatory interventions upon weight in patients with mental illness: a meta-analysis of randomised controlled trials

Neuroregulatory interventions have demonstrated significant efficacy in managing overall psychiatric symptoms; however, their impact on weight control among patients with mental illness remains uncertain. This study presents a preliminary meta-analysis aimed at objectively assessing the effects of neuromodulation techniques on weight management in this patient population, thereby guiding future research and clinical practice. We conducted a comprehensive search of six English and four Chinese databases spanning from 1985 to 2024. The study population comprised individuals diagnosed with psychiatric disorders according to the International Classification of Diseases, 11th Revision (ICD-11), the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), or any earlier versions of these manuals. Neuromodulation techniques were employed to manage psychiatric symptoms and regulate body weight in this population. Two researchers independently screened and extracted data from eligible randomized controlled trials (RCTs), resolving any discrepancies through discussion with a third researcher. The quality of the included studies was evaluated using the Cochrane Risk of Bias tool. Subsequently, we pooled the effect size and variance data for body mass index (BMI) and body weight for use in the meta-analysis. We included 10 eligible RCTs involving a total of 528 patients. The types of mental illness encompassed eating disorders, schizophrenia, depression, and others. High heterogeneity was observed among studies using BMI (I² = 79.15%) and weight (I² = 74.89%) as outcome measures. Meta-analysis results indicated that the effect of neuroregulatory techniques on BMI control in patients with mental illness was not statistically significant (Hedges’ g = -0.44; 95% CI [-1.00, 0.12]; P = 0.127). Similarly, the impact of neuromodulation techniques on weight control in this patient population was also not statistically significant (Hedges’ g = -0.36; 95% CI [-0.85, 0.13]; P = 0.153). Currently, there is insufficient evidence to support the notion that neuroregulatory interventions influence changes in BMI and body weight among patients with mental illness. Future research should aim to validate these findings through rigorously designed RCTs featuring larger sample sizes and extended follow-up periods.