GLP-1 medicines linked to fewer psychiatric hospital stays in people with schizophrenia and diabetes

A study of more than 70,000 US patients found lower rates of psychiatric admissions and emergency visits among people taking GLP-1 drugs, but researchers caution that the findings do not prove cause and effect.

A large study published in The Lancet Psychiatry has found that some medicines widely used for type 2 diabetes and weight management were associated with fewer psychiatric hospital stays among adults who had both schizophrenia and diabetes. Researchers looking at more than 70,000 US patients said the pattern raises the possibility that drugs acting on the hormone GLP-1 may offer benefits beyond glucose control, although the analysis cannot prove a direct cause and effect. According to the report, the medicines studied included semaglutide, liraglutide, dulaglutide and tirzepatide.

The research compared people who started a GLP-1-based treatment with similar patients who began taking two other classes of diabetes medicines, known as DPP-4 inhibitors and SGLT2 inhibitors, as well as with patients who were not taking any of those drug groups. Psychiatric admissions were 24% lower in the GLP-1 group than in the group using none of the medicines examined, while the reductions were 18% versus DPP-4 inhibitors and 17% versus SGLT2 inhibitors. Emergency department visits followed a similar direction, with lower rates ranging from 13% to 29% across the comparisons.

The findings were strongest among people who lost weight, but the same general pattern was also seen in patients whose weight stayed level or rose, suggesting that weight loss alone may not explain the result. The authors also reported that the associations appeared clearer for semaglutide, liraglutide and tirzepatide than for dulaglutide, indicating that these drugs should not automatically be treated as interchangeable for this question. Because the study used health records rather than random assignment, other differences in treatment, illness severity or care could still have influenced the outcome.

The new paper adds to a wider and still unsettled discussion about the psychiatric effects of GLP-1 medicines. Other recent analyses have raised questions about possible links with depression, anxiety and suicidality, while a post hoc analysis of tirzepatide in obesity trials did not find significant changes in depressive symptoms or suicidal thinking compared with placebo. Taken together, the evidence suggests that these drugs may warrant closer study in mental health settings, but not as substitutes for established psychiatric care.