Study Reveals Some Antidepressants Are More Likely to Cause Weight Gain

Highlights:

• Escitalopram, paroxetine, and duloxetine are linked to greater weight gain compared to sertraline after six months.
• Bupropion shows a lower likelihood of weight gain than sertraline during the same timeframe.
• These findings guide doctors and patients in selecting treatments to minimize weight-related concerns.

Weight Gain and Antidepressants: A Common Concern

For many individuals taking antidepressants, weight gain is an all-too-common side effect. Over time, these extra pounds can increase the risk of conditions such as heart disease and diabetes. Additionally, weight gain can discourage patients from following their prescribed treatment plans, leading to inconsistent use or premature discontinuation.

The likelihood and degree of weight gain can vary based on the specific antidepressant used. For example, some SSRIs (selective serotonin reuptake inhibitors) are more likely to contribute to weight gain, whereas medications like bupropion (Wellbutrin) may even promote slight weight loss.

A recent study, published in the Annals of Internal Medicine, provides a clearer picture of how weight changes vary across common antidepressants, offering helpful insights for treatment decisions.

What the Study Found

The study analyzed data from over 183,000 adults who began taking antidepressants for the first time. Researchers assessed weight changes over six months, one year, and two years for individuals prescribed eight commonly used medications, including sertraline (Zoloft), citalopram (Celexa), escitalopram (Lexapro), paroxetine (Paxil), duloxetine, venlafaxine (Effexor XR), and bupropion (Wellbutrin).

Key findings include:

• Bupropion users were 15–20% less likely to experience significant weight gain compared to those taking sertraline.
• Escitalopram and paroxetine were associated with a 10–15% higher risk of significant weight gain than sertraline within the first six months.
• Significant weight gain was defined as an increase of more than 5% of the individual’s starting weight.

Weight Gain Trends Across Medications

When comparing antidepressants, the study revealed clear differences in weight changes:

• Escitalopram and paroxetine users experienced the most weight gain during the first six months, gaining approximately 1 pound more than those on sertraline.
• In contrast, bupropion users lost about 0.5 pounds compared to sertraline users in the same timeframe.
• Duloxetine, venlafaxine, and citalopram were linked to more modest weight increases, ranging between 0.25 and 0.75 pounds compared to sertraline.

Long-Term Use Brings Greater Weight Gain

Over time, weight gain becomes more pronounced for individuals taking antidepressants. According to the study:

• Sertraline users gained an average of 3.2 pounds after two years, compared to just 0.5 pounds after six months.
• Escitalopram users gained approximately 3.6 pounds after two years, while those on paroxetine gained around 3 pounds.
• Bupropion users, despite losing some weight initially, gained about 1.2 pounds on average after two years.

While the differences between medications were less pronounced after two years, researchers note that early weight gain could discourage patients from continuing their treatment, even if the medication is effective.

Expert Insights

“There are clear differences in weight gain among antidepressants, even within the same drug class,” explains Dr. Joshua Petimar, the study’s lead author and assistant professor at Harvard Medical School. “These findings can help doctors and patients make more informed choices, particularly when weight gain is a concern.”

Long-term antidepressant use is often necessary for managing chronic depression. However, understanding how medications impact weight allows healthcare providers to choose treatments that align with each patient’s needs and goals.

What This Means for Patients

Weight gain is just one factor to consider when starting antidepressant treatment. While medications like bupropion may offer a lower risk of weight gain, other factors such as effectiveness and side effects must also be taken into account.

By working closely with healthcare providers, patients can find the right balance between managing their depression symptoms and minimizing unwanted side effects like weight gain.