Post hoc analysis of STEP 1, 2, 3, and 5 trials (3,681 participants) found semaglutide 2.4 mg did not increase depression or suicidal ideation and was associated with a small reduction in depressive symptoms vs placebo.
No psychiatric risk increaseSemaglutide 2.4 mg showed no increase in depression (PHQ-9) or suicidal ideation vs placebo across 4 STEP trials
What the researchers found
Semaglutide 2.4 mg did not increase depression (PHQ-9 treatment difference -0.56, p<0.001) or suicidal ideation (≤1% both groups) vs placebo across STEP 1, 2, 3, and 5 trials in participants without major psychopathology.
Why it matters
Media reports and regulatory inquiries raised concerns about GLP-1 drugs and mental health. This analysis of the largest semaglutide weight management dataset provides robust evidence that semaglutide is psychiatrically safe — and may even slightly improve mood.
The numbers in context
Pooled data from STEP 1, 2, 3, and 5 trials; semaglutide 2.4 mg weekly vs. placebo; psychiatric adverse events assessed.
How the study worked
Post hoc analysis of pooled data from 4 randomized, double-blind, placebo-controlled STEP trials (3,377 from STEP 1-3 at 68 weeks + 304 from STEP 5 at 104 weeks). PHQ-9 for depression, Columbia-Suicide Severity Rating Scale for suicidal ideation.
Who was studied
Adults with obesity without known major psychopathology
What this study cannot tell us
Post hoc analysis — not designed as a psychiatric safety trial. Excluded participants with known major psychopathology at baseline. PHQ-9 improvement of -0.56 is statistically significant but not clinically meaningful. Short to medium follow-up. Does not address patients with pre-existing mental health conditions.
How to read the evidence
Strong evidence — large pooled post hoc analysis from well-designed RCTs with validated psychiatric assessments. Limited by exclusion of patients with baseline psychopathology.
When this study was published
Published in 2024. Addresses timely concerns about GLP-1 drug psychiatric safety.
The bigger picture
As GLP-1 drugs reach tens of millions of users, psychiatric safety data is essential for public confidence. This analysis provides the largest and most rigorous assessment to date, finding no signal for psychiatric harm and a small signal for potential mood benefit.
Questions still open
- Is semaglutide safe for patients WITH pre-existing depression or other psychiatric conditions?
- Does the small mood improvement reflect direct neurological effects of semaglutide or the psychological benefit of weight loss?
- Are the psychiatric safety findings generalizable to higher semaglutide doses or oral formulations?
Common questions
Does semaglutide cause depression or suicidal thoughts?
Should I worry about my mental health if I'm taking Wegovy?
Read the original research
Psychiatric Safety of Semaglutide for Weight Management in People Without Known Major Psychopathology: Post Hoc Analysis of the STEP 1, 2, 3, and 5 Trials.
JAMA internal medicine, 184(11), 1290-1300
Citation
Wadden, Thomas A; Brown, Gregory K; Egebjerg, Christina; Frenkel, Ofir; Goldman, Bryan; Kushner, Robert F; McGowan, Barbara; Overvad, Maria; Fink-Jensen, Anders. (2024). Psychiatric Safety of Semaglutide for Weight Management in People Without Known Major Psychopathology: Post Hoc Analysis of the STEP 1, 2, 3, and 5 Trials.. JAMA internal medicine, 184(11), 1290-1300. https://doi.org/10.1001/jamainternmed.2024.4346