A recent study examined the long-term effects of antidepressant use on body weight among a cohort of Spanish adults.

Published in Frontiers in Psychiatry, the research—conducted by Camille Lassale of the Hospital del Mar Medical Research Institute in Barcelona, and colleagues—involved 3,127 participants who were an average age of 55.6 years and followed-up with after approximately 6.3 years. The findings indicated that different patterns of antidepressant use were associated with significant weight gain.

The study utilized a prospective population-based cohort design, drawing data from the REGICOR study in northeastern Spain. Participants provided self-reported information on antidepressant use, body weight, height, and various lifestyle factors, including smoking status, physical activity, and diet quality.

Participants were categorized into four trajectories of antidepressant use: never users, new users at follow-up, initial users who discontinued, and repeated users at both time points. The results showed that 83.6% of participants reported no use of antidepressants, while 6.2% initiated use during follow-up, 5.1% discontinued use, and another 5.1% reported consistent use.

Over the 6-year period, participants gained an average of 0.53 kg, which represented a 1.01% increase in body weight. Notably, 24.5% of participants experienced weight gain that exceeded 5%. Multivariable analyses revealed that all trajectories of antidepressant use were associated with greater weight gain compared to never users. Specifically, initial users who discontinued gained +1.78% (95% confidence interval [CI] = 0.57, 2.98), new users at follow-up gained +2.08% (95% CI = 0.97, 3.19), and repeated users gained +1.98% (95% CI = 0.75, 3.20).

For participants without obesity at baseline, the odds ratio for becoming obese was 2.06 (95% CI = 1.03, 3.96) for those with repeated antidepressant use, while the other trajectories did not show statistically significant associations with obesity incidence.

"Given the global obesity epidemic and the widespread use of antidepressants, weight management and metabolic monitoring should be encouraged and integrated into depression follow-up guidelines alongside antidepressant prescriptions," the researchers suggested.

No conflicts of interest were reported.