Eight Common Antidepressants Ranked by Weight Gain Potential

Eight commonly used antidepressants have been ranked by their weight gain potential. 

Results of a large observational study showed small differences in short- and long-term weight change in patients prescribed one of eight antidepressants, with bupropion associated with the lowest weight gain and escitalopram, paroxetine, and duloxetine associated with the greatest. 

Escitalopram, paroxetine, and duloxetine users were 10%-15% more likely to gain at least 5% of their baseline weight compared with those taking sertraline, which was used as a comparator. 

Investigators noted that the more clinicians and patients know about how a particular antidepressant may affect patients’ weight, the better informed they can be about which antidepressants to prescribe. 

“Patients and their clinicians often have several options when starting an antidepressant for the first time. This study provides important real-world evidence regarding the amount of weight gain that should be expected after starting some of the most common antidepressants,” lead author Joshua Petimar, ScD, assistant professor of population medicine in the Harvard Pilgrim Health Care Institute at Harvard Medical School, Boston, said in a press release. 

The findings were published online on July 1 in the Annals of Internal Medicine. 

Real-World Data

Though weight gain is a commonly reported side effect of antidepressant use and may lead to medication nonadherence and worse outcomes, there is a lack of real-world data about weight change across specific medications. 

Investigators used electronic health records from eight healthcare systems across the United States spanning from 2010 to 2019. The analysis included information on 183,118 adults aged 20-80 years who were new users of one of eight common first-line antidepressants. Investigators measured their weight at baseline and at 6, 12, and 24 months after initiation to estimate intention-to-treat (ITT) effects of weight change.

At baseline, participants were randomly assigned to begin sertraline, citalopram, escitalopram, fluoxetine, paroxetine, bupropion, duloxetine, or venlafaxine. 

The most common antidepressants prescribed were sertraline, citalopram, and bupropion. Approximately 36% of participants had a diagnosis of depression, and 39% were diagnosed with anxiety.

Among selective serotonin reuptake inhibitors (SSRIs), escitalopram and paroxetine were associated with the greatest 6-month weight gain, whereas bupropion was associated with the least weight gain across all analyses.

Using sertraline as a comparator, 6-month weight change was lower for bupropion (difference, 0.22 kg) and higher for escitalopram (difference, 0.41 kg), duloxetine (difference, 0.34 kg), paroxetine (difference, 0.37 kg), and venlafaxine (difference, 0.17 kg).

Escitalopram, paroxetine, and duloxetine users were 10%-15% more likely to gain at least 5% of their baseline weight compared with sertraline users.

Investigators noted little difference in adherence levels between medications during the study except at 6 months, when it was higher for those who took bupropion (41%) than for those taking other antidepressants (28%-36%).

The study included data only on prescriptions and investigators could not verify whether the medications were dispensed or taken as prescribed. Other limitations included missing weight information because most patients did not encounter the health system at exactly 6, 12, and 24 months, only 15%-30% had weight measurements in those months. 

Finally, the low adherence rates made it difficult to attribute relative weight change at the 12- and 24-month time points to the specific medications of interest.

“Clinicians and patients could consider these differences when making decisions about specific antidepressants, especially given the complex relationships of obesity and depression with health, quality of life, and stigma,” the authors wrote. 

The study was funded by the National Institute of Diabetes and Digestive and Kidney Diseases. Disclosures are noted in the original article.