Semaglutide Demonstrates Significant Metabolic Benefits in Schizophrenia Patients on Antipsychotic Therapy
Key Insights
Semaglutide reduced HbA1c levels by 0.25% compared to placebo in patients with schizophrenia (search) taking second-generation antipsychotics, with nearly 50% achieving low-risk glycemic targets.
Patients experienced substantial weight loss averaging 9.2 kg over 26 weeks, along with significant reductions in waist circumference and fat mass.
The treatment showed no negative impact on psychiatric symptoms or mental health status, with adverse events primarily limited to mild gastrointestinal effects.
A groundbreaking randomized clinical trial has demonstrated that low-dose semaglutide significantly improves metabolic outcomes in patients with schizophrenia (search) who are receiving second-generation antipsychotic medications. The study, published in JAMA Psychiatry, represents the first randomized trial to evaluate the diabetes (search) drug's efficacy in this vulnerable population, who face substantially higher risks of weight gain, insulin resistance, and type 2 diabetes due to their psychiatric medications.
Study Design and Population
The multicenter, double-blind trial enrolled 73 adults aged 18 to 65 years across three Danish clinical sites between 2021 and 2024. Participants had schizophrenia (search) spectrum disorders and had initiated clozapine or olanzapine within the previous five years. All showed signs of early glycemic abnormalities with HbA1c levels ranging from 5.4% to 7.4%, and none were receiving antidiabetic medication at baseline.
Participants were randomized to receive either weekly subcutaneous semaglutide (1 mg) or matching placebo for 26 weeks, alongside their existing antipsychotic therapy. The primary endpoint focused on changes in HbA1c from baseline to week 26.
Significant Glycemic Improvements
Semaglutide produced a statistically significant improvement in glycemic control, with an HbA1c reduction of −0.25% compared with placebo. The clinical impact was particularly striking: nearly 50% of participants receiving semaglutide achieved low-risk HbA1c levels below 5.4%, whereas only 3% of those on placebo reached this target.
According to the research team led by Marie R. Sass from the Mental Health Center Copenhagen (search), these results suggest that semaglutide may help reverse early metabolic abnormalities before they progress to overt diabetes (search).
Substantial Weight Loss and Body Composition Changes
Beyond glycemic control, participants on semaglutide experienced substantial weight loss, averaging 9.2 kg over 26 weeks. The metabolic benefits extended to body composition, with significant reductions in waist circumference (−7.0 cm) and fat mass (−6.1 kg).
Safety and Psychiatric Stability
Importantly, no meaningful changes were noted in psychiatric symptoms, demonstrating that metabolic benefits did not compromise mental health status. Adverse events were largely gastrointestinal, mild, and short-lived, consistent with known GLP-1 receptor (search) agonist effects. Psychiatric adverse events appeared at similar rates in both groups, reinforcing the overall tolerability of semaglutide in individuals with severe mental illness.
Clinical Implications
The findings address a critical unmet need in schizophrenia (search) care. Individuals receiving second-generation antipsychotics face substantially higher risks of metabolic complications that contribute to excess cardiovascular mortality in this population. The study explored whether adding a glucagon-like peptide-1 receptor agonist early in treatment could counteract these metabolic disturbances.
As noted by Ashok A. Ganeshalingam, MD, from the Department of Endocrinology at Odense University Hospital, Denmark, "overweight or obese patients without diabetes (search) with [schizophrenia (search)] and [second-generation antipsychotic] treatment have an increased responsiveness to semaglutide, but whether this is caused by reductions in the adverse effects of [second-generation antipsychotics] (eg, appetite) or the psychiatric disease per se remains unknown."
Study Limitations and Future Directions
The trial was limited by its 26-30 week duration, which may not reflect long-term effects on glucose control, weight, or psychiatric outcomes. The maximum dose was 1 milligram weekly, lower than the dose approved for obesity (search) in other populations. Additionally, the exclusion of patients with diabetes (search) limited generalizability of the findings.
The authors conclude that early use of semaglutide may serve as an effective adjunctive strategy to mitigate the metabolic burden associated with second-generation antipsychotics. By intervening during the initial stages of metabolic dysregulation, clinicians may help reduce long-term cardiometabolic complications in individuals with schizophrenia (search) spectrum disorders.