A study reveals that GLP-1 drugs for obesity are associated with fewer psychiatric hospitalizations in cases of schizophrenia.

Schizophrenia affects about 27 million people worldwide, according to data from the World Health Organization (WHO), and presents a double challenge: in addition to psychotic symptoms (such as hallucinations, delusions, and thought alterations), those who suffer from it experience very high rates of type 2 diabetes, obesity, and cardiovascular disease. Much of this metabolic burden comes from the antipsychotics themselves, the drugs that form the pillar of treatment. These medications cause weight gain, insulin resistance, and other adverse effects that, in turn, can lead patients to discontinue medication and relapse. In this context, GLP-1 receptor agonists (a class of drugs designed to treat diabetes and obesity) have sparked scientific interest in their potential impact beyond metabolism: their receptors are present in regions of the brain linked to cognition, motivation, and appetite regulation. ADVERTISEMENT A large-scale study published in The Lancet Psychiatry analyzed data from over 70,000 adults with schizophrenia and type 2 diabetes in the United States to evaluate whether the initiation of these drugs was associated with fewer psychiatric hospitalizations and emergency room visits. Schizophrenia is a serious psychiatric disorder that affects perception, thought, and behavior. Those who suffer from it face a disproportionate burden of metabolic problems (such as obesity, insulin resistance, and altered cholesterol levels), partly caused by the antipsychotics themselves that form the basis of their treatment. This combination contributes to high premature mortality, especially from cardiovascular diseases. ADVERTISEMENT The central finding of the study is that the initiation of GLP-1 receptor agonists was associated with a 24% reduction in the risk of psychiatric hospitalization compared to those who did not receive these drugs. The reduction was also notable compared to the other two antidiabetic medications: DPP-4 inhibitors (18% reduction) and SGLT2 inhibitors (17% reduction). Regarding psychiatric emergency visits, the pattern was even more marked. The risk was reduced by 29% compared to no initiation, 13% compared to DPP-4 inhibitors, and 20% compared to SGLT2 inhibitors. These associations were consistently maintained among adults under 55 years old, males, and patients under antipsychotic treatment. ADVERTISEMENT However, the study points out that the associations were not uniform across all subgroups. In adults over 55 years old, in people who did not receive antipsychotics, and in those with the lowest body weight in the group, the differences were not consistent enough to confirm a real effect of the treatment. According to the authors, "GLP-1 receptor agonists should not be considered a primary psychiatric treatment nor prescribed solely to reduce the use of acute psychiatric care based on current evidence." More than 70,000 patient medical records with schizophrenia and diabetes formed the basis of the study. To arrive at these conclusions, the team designed an observational cohort study (i.e., without intervening on the patients) using data from the NeuroBlu Data repository, a platform that integrates anonymized clinical information from hundreds of mental health providers in the United States. ADVERTISEMENT The final cohort included 70,257 adults with documented diagnoses of schizophrenia and type 2 diabetes between January 1, 2018, and October 1, 2025. Of the total, 9,093 patients (12.9%) started treatment with GLP-1 receptor agonists; 4,968 (7.1%) with DPP-4 inhibitors; 5,328 (7.6%) with SGLT2 inhibitors; and 50,868 (72.4%) did not start any of these three drugs. The average age was 53 years, and 48.2% were women. Psychiatric benefit could accompany metabolic treatment, but clinical trials are still needed. The article emphasizes that GLP-1 receptors are present in regions of the brain linked to cognition, motivation, stress response, and appetite regulation. These receptors participate in the modulation of dopaminergic pathways (the brain circuits that regulate, among other functions, the sense of reward and pleasure) and in neuroinflammation, that is, the inflammation that occurs within the nervous system and is associated with schizophrenia. ADVERTISEMENT Among the class of GLP-1 agonists, not all drugs showed the same association. Semaglutide, liraglutide, and tirzepatide consistently showed a lower risk of acute psychiatric events compared to the three comparison groups. In contrast, dulaglutide did not show a favorable association and was even linked to an increased risk when compared with SGLT2 inhibitors. The authors acknowledge relevant limitations. As it is a study that only observed what already happened without controlling variables as in an experiment, it is not possible to confirm that the drugs are the direct cause of the results. Furthermore, the data come from people with health insurance coverage in the United States, which limits the possibility of extending the conclusions to populations without health insurance or outside that system. ADVERTISEMENT The study also could not measure whether patients took the medication consistently or whether they changed their treatment during the follow-up. "The reduced use of psychiatric services could reflect differences in access to care, disengagement from the healthcare system, or competition with other medical care," researchers warn.