Antidepressants may cause weight gain - Study

A new study out of Britain finds that using antidepressants could lead to weight gain over time.

The widespread, long-term use of antidepressants may be contributing to increased weight gain at a population level, a new study from the United Kingdom suggests.

Results showed that patients who were prescribed any of the 12 most common antidepressants were more likely to experience weight gain than those not taking the drugs. The risk was greatest during the second and third years of treatment

Researchers looked at almost 300,000 people and found that those on antidepressants were 21-percent more likely to gain at least 5-percent of their body weight over 10 years.

The greatest weight gain occurred in the second and third years of treatment but seemed to persist for at least six years.

We’ve known for some time that antidepressants are associated with some weight gain, but patients should not stop taking their antidepressants.

They should simply be aware of the potential for weight gain and take steps to try to avoid it.

Furthermore, they discovered that some medications were more strongly associated with weight gain than others.

People who took mirtazapine were 50 percent more likely to gain weight, and those who took citalopram had a 26 percent higher risk of weight gain.

The researchers did note some limitations. They said the medical regimens of some patients may have influenced their diets, and that depressive symptoms, such as increased appetite and decreased motivation to exercise, may have contributed to weight gain. 

Despite the findings, the researchers said antidepressants are still useful and patients should be aware of the potential risks.

A variety of factors need to be taken into account when prescribing any given antidepressant, Gafoor said.

The best advice is to have an open, informed conversation with your prescriber if weight gain (or any other side effect) is bothersome.