The answer to this question is that they just might, especially if you are taking a certain type of antidepressant.
Of course there is a lot more to the story. People gain and lose weight for a variety of reasons. Being depressed in itself can cause great fluctuations in weight. I know for me, I have had the experience of both gaining and losing weight while depressed. When I am depressed and feel anxious I tend to lose weight. When I am chronically mildly depressed over a long period of time, I tend to engage in mindless eating and gain weight. And likewise when I am feeling better and coming out of a depression, I eat more. When I feel happy I tend to enjoy food more. Everyone is different in how their weight will fluctuate with their mood.
One hypothesis for why some of us gain weight when we are taking antidepressants is that as we begin to feel better and rediscover pleasure, we like to eat more. Some people, like me, eat more when we feel happier.
There could also be a medical reason for weight gain during depression. An underactive thyroid problem can cause both depression and weight gain. An underactive thyroid can greatly change your energy level for the worse. The person who suffers from an underactive thyroid feels great fatigue, feels cold, has diminished concentration and memory, and suffers from weight gain. So if you are feeling tired, depressed, and gaining weight, it might be wise to go see your doctor to check out your thyroid.
But is there a connection between the use of some antidepressants and weight gain?
Many antidepressant users and medical experts would say yes.
How many people are gaining weight on their antidepressants? In an article entitled, "Fat Pharms: Antidepressants and Weight Gain" the author estimates that for up to 25% of the people who take anti-depressants will have a weight gain of ten pounds or more. Add to this Psychiatrist Daniel-Hall's prediction that: " Recent research has shown that people who gain weight within about the first week of starting antidepressant treatment are more likely to have significant weight gain from the medication over an extended period of time. " So it seems if you start off gaining right away while on an antidepressant, this does not bode well for maintaining your weight in the long term.
Which brings us to what you really want to know and that is:
"Which antidepressants are more likely to cause weight gain?
Predominantly the medical literature is in agreement that Paxil can cause you the most weight gain. Of course it greatly depends on the individual but individuals report weight gain ranging from 20-50 pounds. According to Janet Kinosian, in her article entitled, "Antidepressants & Weight Gain, she reports that Paxil, Zoloft, Remeron, and Luxox cause the most weight gain