People with schizophrenia experience three to five times higher prevalence of diabetes and obesity than the general population, contributing to a 20-year reduced lifespan. The impacts of weight gain extend beyond physical health, affecting people's self-esteem, quality of life, and triggering treatment nonadherence, leading to relapse and deteriorations in health. Clinical guidelines recommend patients with antipsychotic-induced weight gain are treated with cognitive behaviour therapy and lifestyle changes; however, effective treatments for obesity in schizophrenia are critically lacking. Glucagon-like peptide-1 receptor agonists (GLP-RAs) have shown large effects in weight loss in the general population; however, effects are less clear in people with schizophrenia. This review aims to assess the clinical trials that have been completed, are in progress, and directions for future trials.

To date, six clinical trials have been completed, four of which have published their findings. Three further trials are currently in progress.

Results from completed trials suggest that GLP-1RAs decrease weight in people with schizophrenia, however effect sizes are mostly smaller than studies based on the general population. Future trials could focus on dual or triple agonist agents, and/or explore the effects of GLP-1 s at antipsychotic medication commencement, to potentially prevent antipsychotic weight gain.