A recent study examined weight change associated with eight commonly prescribed antidepressant medications. The researchers followed 183,118 patients who commenced antidepressant treatment between 2010 and 2019 across 8 U.S. health systems.
The antidepressants analyzed included sertraline, escitalopram, paroxetine, duloxetine, bupropion, fluoxetine, citalopram, and venlafaxine. The most common antidepressant prescribed in the study was sertraline. Users of bupropion gained 0.22 kg less weight than sertraline users and had a 15% lower risk of gaining 5% of baseline weight.
Patients treated with the antidepressants escitalopram, paroxetine, and duloxetine experienced an average weight gain of 0.3 to 0.4 kg more compared to those taking sertraline after 6 months. Moreover, they had a 10% to 15% higher risk of gaining at least 5% of their baseline body weight, according to finds published in the Annals of Internal Medicine.
Citalopram and venlafaxine were also associated with greater 6-month weight gain than sertraline, though to a lesser degree than escitalopram, paroxetine and duloxetine (0.12 kg more for citalopram and 0.17 kg more for venlafaxine). Fluoxetine was not associated with a significant weight change compared to sertraline.
The study also examined weight change at 12 and 24 months after starting treatment. At 24 months, duloxetine and venlafaxine were associated with less weight gain than sertraline, in contrast to the 6-month findings. Bupropion continued to be associated with the least weight gain at both 12 and 24 months.
Although the differences in weight gain between medications were relatively modest, investigators noted even small amounts of weight gain can have an impact on long-term metabolic health. Furthermore, weight gain is a frequently cited reason for patients discontinuing antidepressants.
The study investigated both the effects of starting an antidepressant and the effects of starting and consistently taking an antidepressant as prescribed. Adherence to the medications was found to be low, with only about 28% to 41% of patients still taking their originally prescribed medication after 6 months, dropping to 16% to 21% at 1 year and 4% to 5% at 2 years.
The researchers noted when selecting between antidepressant options, physicians and patients should consider the potential for weight gain, especially for patients at higher risk for weight-related health problems. However, they acknowledged that individual treatment decisions involve weighing multiple patient-specific factors.
The observational study used real-world data from electronic health records, allowing the researchers to examine a large, diverse patient population and compare multiple antidepressants simultaneously, which would be challenging in a traditional clinical trial. The authors noted some limitations, such as potential confounding by indication and reliance on prescriptions rather than verified medication intake, but they used advanced statistical methods to mitigate the limitations.
The findings were generally consistent with prior studies, but the new study was more comprehensive in terms of the number of antidepressants compared, the use of a new-user design, and the examination of both short- and long-term weight change, noted investigators.
The study, funded by the National Institute of Diabetes and Digestive and Kidney Diseases, employed advanced statistical methods to emulate a randomized clinical trial by adjusting for differences between patients taking each medication.
The authors declared having no competing interests.
