Is That Antidepressant Making You Fat?

“I hate it! I’ve gained 14 pounds.” Becky, a depressed client I was seeing, was complaining about the weight she’d gained since starting on Celexa. She was thinking of quitting the antidepressant, but Becky wasn’t alone — other clients I've treated for depression would complain about gaining weight on their antidepressants.

Source: Edward Abramson, PhD

Some depressed people lose weight because they’ve lost their appetite. They would complain, “Nothing tastes good,” but they were in the minority. More often depression was linked to increased appetite and more eating, usually a lot of carbs, either sweets like cookies and brownies or other calorically dense foods like pizza or French fries. Typically the clients were trying to feel better and lift their mood by eating favorite foods but some clients denied that they were eating more because of their depression. Instead, they attributed their increased weight to the antidepressant medication they were taking.

A new review article in the November issue of the journal Obesity systematically examines the effects of antidepressants on weight. Previous research has shown that almost two-thirds of long-term users of antidepressants gained weight and this unwanted weight gain was a major cause of patients discontinuing their use of the antidepressant. The article had a lot of detail so I’ll just provide an overview.

There are several categories of antidepressants: MAOIs (monoamine oxidase inhibitor), TCAs (tricyclics), SSRIs (selective serotonin reuptake inhibitors), SNRIs (serotonin norepinephrine reuptake inhibitors), etc. Within each category, there is variation in the effects on weight; no single category causes weight gain or has a neutral effect on weight. For example, among the MAOIs, Nardil presents a high risk of weight gain while Parnate is associated with a low risk. Similarly, there’s variability among TCAs. Pamelor has been shown to cause weight gain while Tofranil is less likely to add weight.

The SSRIs like Prozac, Zoloft (the most commonly prescribed antidepressant), Lexapro, Celexa, and Paxil are widely used antidepressants. In one study, 13 percent of patients on Celexa reported a seven percent weight gain after nine months. Another study found an average weight gain of six pounds after two years. In contrast, Prozac is generally considered weight neutral over the short term with moderate weight gain over longer periods.

It’s important to recognize that the effect on weight is not the only side effect to consider in determining the best pharmaceutical treatment for depression. Antidepressants can have a variety of other side effects including dizziness, nausea, dry mouth, or sexual difficulties.

If you’re on an antidepressant and have gained weight, or if you’ve been encouraged to try an antidepressant but you’re concerned about possible weight gain, the article in Obesity would be helpful. You might have an experience like Becky’s with a period of trial and error before you find an antidepressant with minimal side effects that will help alleviate the depression without gaining weight.