A systematic review of 11 observational studies representing more than 4.9 million patients found that GLP-1 receptor agonists were generally associated with neutral or potentially protective psychiatric outcomes, although one obesity-focused cohort reported increased risks of depression, anxiety, and suicidal behavior. Direct evidence for antidepressant effects remains limited, with only one cross-sectional study using validated mood scales and no randomized trials in the final synthesis, meaning causality cannot be established
