Diabetes and weight loss drugs are showing an unexpected benefit: they appear to substantially reduce psychiatric hospital visits and mental health-related sick leave, according to a large Swedish study published in The Lancet Psychiatry.
The research, conducted by scientists from the University of Eastern Finland, Karolinska Institutet in Sweden, and Griffith University in Australia, followed nearly 100,000 people between 2009 and 2022. More than 20,000 participants used GLP-1 receptor agonists during that period, a drug class that includes the popular brands Ozempic and Wegovy.
The findings were striking. When people took semaglutide, the active ingredient in both drugs, psychiatric-related hospital visits and work absences dropped 42 percent compared to periods when they were not using the medication. The risk of depression fell 44 percent, while anxiety disorders decreased by 38 percent.
Substance use disorders also showed improvement. Hospital care and missed work linked to substance use declined 47 percent during semaglutide treatment. The drugs were additionally associated with reduced risk of suicidal behavior.
The connection between metabolic disease and mental illness has long puzzled researchers. Obesity and type 2 diabetes significantly increase the risk of depression, anxiety, and other psychiatric conditions. People with mental health disorders, meanwhile, face higher odds of developing metabolic problems. This bidirectional relationship suggested that treating one might help the other, but the strength of these results surprised even the research team.
Mark Taylor, one of the study's authors from Griffith University, noted that earlier work had already documented a link between GLP-1 use and reduced alcohol use disorder risk. "Alcohol-related problems often have downstream effects on mood and anxiety, so we expected the effect to be positive on these as well," he said.
The exact mechanism remains unclear. Registry-based studies like this one cannot definitively explain cause and effect. Markku Lähteenvuo, research director at the University of Eastern Finland, suggested multiple pathways could be at work. "It is possible that, in addition to factors such as reduced alcohol consumption, weight loss-related improvements in body image, or relief associated with better glycemic control in diabetes, there may also be direct neurobiological mechanisms involved, for example through changes in the functioning of the brain's reward system," he said.
While smaller studies on GLP-1 drugs and mental health have produced mixed results, this long-term analysis of nearly 100,000 people provides stronger evidence that these widely prescribed medications influence mental well-being in addition to managing blood sugar and weight.
Author Jessica Williams: "If these findings hold up in clinical trials, we're looking at a completely different rationale for prescribing these drugs beyond waistlines and blood glucose."
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