The best time to take antidepressants is shortly after you wake up. This should help prevent the risk of withdrawal symptoms, including muscle pain and other flu-like symptoms, which are common when people abruptly stop taking antidepressants. However, it’s important not to wait too long between doses or you could run into trouble with side effects like constipation or dry mouth. “If an antidepressant isn’t taken consistently for a month or two months at a time, then it may be ineffective,” says Dr. O’Connor. If that happens, he recommends trying another medication in its place before switching back to an antidepressant that works better for your needs.