Do GLP-1 Drugs Affect Mental Health? A Systematic Review of Psychiatric Effects

This systematic review of GLP-1 receptor agonist psychiatric effects found a mixed but intriguing picture: modest antidepressant effects were observed across studies, and there were signs of potential benefit for eating disorders and substance use disorders — conditions driven by reward system dysregulation. However, the link between GLP-1 drugs and suicidal thoughts remained inconclusive, with studies showing inconsistent results. In people with schizophrenia, GLP-1 drugs improved metabolic health but did not consistently affect psychiatric symptoms.

The researchers systematically searched PubMed/MEDLINE, Cochrane Central Register, Embase, and Web of Science for all studies examining associations between GLP-1 receptor agonists and psychiatric outcomes including depression, suicidality, eating disorders, substance use disorders, and schizophrenia. Studies were evaluated for quality and findings were synthesized narratively across each psychiatric domain.

With tens of millions of people now taking GLP-1 drugs like semaglutide and tirzepatide, understanding their effects on mental health is critical. Reports of reduced alcohol cravings, changed relationships with food, and concerns about suicidal ideation have made headlines. This review is the first systematic attempt to sort signal from noise across the full spectrum of psychiatric effects — and the answer is that some effects look real (antidepressant, anti-craving) while others (suicidality) remain unresolved.

GLP-1 receptors are found throughout the brain, not just in the gut and pancreas. This means GLP-1 drugs almost certainly affect brain function in ways we're still discovering. The observation that people on these drugs sometimes lose interest in alcohol, gambling, or compulsive eating suggests they may modulate the brain's reward system. If confirmed, this could open entirely new therapeutic uses for GLP-1 drugs — but the suicidality question needs resolution first, especially given the scale of prescribing.

The included studies varied widely in dosing, clinical indication (diabetes vs. obesity), and whether patients had pre-existing psychiatric conditions. People with psychiatric comorbidities were consistently underrepresented in the original trials. Sample diversity was limited across studies. The heterogeneity made it difficult to draw firm conclusions, particularly about suicidality risk.