People who take antidepressant medications for many years often complain that they gain weight. Is this observation merely anecdotal, or is there evidence to support it?
Do People Gain Weight When They Take Antidepressants?
An epidemiological study published in the BMJ tracked nearly 300,000 people for more than a decade (BMJ, May 23, 2018). Those taking antidepressant medications were more likely to put on pounds than matched controls who were not taking antidepressants.
People who started at normal weight were more likely to become overweight if they took an antidepressant, while those who were overweight at the outset were more likely to become obese. This risk became apparent during the second and third year on the medications.
The authors suggest that “the widespread use of antidepressants might be an important factor contributing to increasing body weight.”
The Risk Is Not High, But It Is Wide:
An editorial in the same issue points out that the increased risk that a person will gain weight is modest: 11.2 per 100 person-years of follow-up among people taking antidepressants compared to 8.1 per 100 person-years for people not taking the drugs. The difference is only about 3 people who gain weight out of 100 people followed up for a year. However, because so many people take antidepressants, this could add up to extra pounds for thousands of individuals.
Knowledge about the possibility of weight gain should not keep people from taking antidepressant medications, but it should make both doctors and patients vigilant about this potential adverse reaction.
