I am on welbutrin (bupropion) for depression and I have heard that it prevents weight gain. Is this true?

It is true that wellbutrin does prevent weight gain, but this is only seen in less than 5% of depressed patients. More important is that this weight loss with bupropion is only seen in the first few weeks after starting the drug. Unfortunately, the weight is immediately regained over the ensuing months. There is no antidote to weight gain caused by wellbutrin except for exercise and eating less.