A study of more than 70,000 US adults found lower rates of psychiatric hospitalisation and emergency care among people with schizophrenia and type 2 diabetes who started GLP-1 medicines, although researchers caution that the findings do not prove a direct psychiatric benefit.
A large US study published in The Lancet Psychiatry has found that adults with schizophrenia and type 2 diabetes who started GLP-1 receptor agonists were less likely to be admitted to hospital for psychiatric reasons or sent to the emergency department than similar patients who did not take the drugs. The research adds to a growing body of evidence suggesting that medicines developed for diabetes and obesity may have wider effects in people with serious mental illness.
The analysis drew on electronic health records from more than 70,000 adults, making it one of the largest studies yet to examine this question in schizophrenia. Researchers compared people who began treatment with GLP-1 drugs with those who started other common diabetes medicines, including DPP-4 inhibitors and SGLT2 inhibitors, as well as those who received none of those therapies. Over follow-up of up to two years, GLP-1 use was linked with a 24% lower risk of psychiatric hospitalisation and a 29% lower risk of psychiatric emergency care than non-use. The associations also held, though to a lesser degree, when GLP-1s were compared with the other diabetes drug classes.
The benefits appeared strongest in younger adults, men and people already taking antipsychotic medicines. Among those on antipsychotics, the researchers estimated that treating 32 patients for a year would prevent one psychiatric hospital admission or emergency visit. The authors also looked at weight change and said the findings suggested that weight loss alone did not fully explain the association. In some analyses, the lower risk of acute psychiatric care was seen even among patients whose weight did not substantially change.
The study’s lead author, Najmeh Davoodian of Deakin Institute for Mental and Physical Health and Clinical Translation in Geelong, Australia, told Medscape Medical News that the results suggested a possible added advantage when GLP-1 receptor agonists are already being used for metabolic reasons. But she stressed that the findings were not strong enough to change prescribing guidance or to support use of the drugs specifically for psychiatric benefit. She said larger replication studies and randomised trials would be needed before that could be considered established.
Other specialists urged caution in interpreting the results. Jon van Niekerk of the Royal College of Psychiatrists, speaking in a statement released by the UK Science Media Centre, said the reductions in hospital and emergency care were clinically meaningful but warned that the study could not show the drugs directly improved psychiatric symptoms or prevented relapse. Sameer Jauhar, of Imperial College London, said patients who are prescribed GLP-1 drugs in the US may differ in important ways from other patients, including better healthcare access and insurance coverage, which could partly explain the findings. He also noted that the study curves separated almost immediately after treatment started, a pattern he said may point to pre-existing differences between groups rather than a delayed drug effect.
Still, clinicians said the work is consistent with a broader trend. Roger McIntyre, a psychiatry and pharmacology professor at the University of Toronto, said the findings echo earlier research suggesting fewer psychiatric hospital admissions among GLP-1 users, including in people with schizophrenia and substance use disorders. He and others also highlighted a practical issue for prescribers: GLP-1 drugs can worsen gastrointestinal side effects, and when they are used alongside antipsychotics such as clozapine and olanzapine, constipation may become more difficult to manage. Sri Mahavir Agarwal, a psychiatrist at the Centre for Addiction and Mental Health in Toronto, said the interaction warrants proactive monitoring, but should not prevent doctors from using GLP-1 treatment when it is otherwise indicated.
The study was supported by an Australian research project funded by the National Health and Medical Research Council. Its authors said the work cannot prove causation, and that differences in treatment adherence, ongoing medication use and healthcare access could all have influenced the results. Even so, the paper adds to a wider literature suggesting that GLP-1 medicines may be safe in people with schizophrenia and diabetes, while raising the possibility that their effects may reach beyond weight and blood sugar control.
Disclaimer: This content is for informational purposes only and is not intended to be a substitute for professional medical judgment, advice, diagnosis, or treatment.
