Researchers identified small but notable differences in weight changes among the medications. Bupropion (Wellbutrin) users experienced a slight average weight loss over time compared to sertraline (Zoloft) users, the reference group. At six months, bupropion users lost an average of half a pound; by two years, they had lost an average of two pounds.
Conversely, patients on escitalopram (Lexapro), paroxetine (Paxil), and duloxetine (Cymbalta) gained more weight, with increases ranging from 0.75 to 0.90 pounds more than sertraline users at six months.
Weight Change by Antidepressant at Six Months Bupropion (Wellbutrin): -0.48 lbs Fluoxetine (Prozac): -0.15 lbs Citalopram (Celexa): +0.
26 lbs Venlafaxine (Effexor): +0.37 lbs Duloxetine (Cymbalta): +0.75 lbs Paroxetine (Paxil): +0.
81 lbs Escitalopram (Lexapro): +0.90 lbs The study also indicated that the increased risk persisted for at least six years, suggesting a long-term link between antidepressant use and weight gain. “Widespread utilisation of antidepressants may be contributing to long-term increased risk of weight gain at a population level,” wrote the authors of the BMJ study.
“The potential for weight gain should be considered when antidepressant treatment is indicated.” Research shows that weight gain from antidepressants can be due to various factors, including changes in brain chemistry and behavior. Many antidepressants boost serotonin levels, a neurotransmitter that influences appetite and metabolism, result.