If you're taking an antidepressant to treat depression—whether it's for the first time, you've recently changed medications, or you're experiencing a repeat episode of depression—you're looking forward to feeling like your old self again. And chances are good that eventually, you will. But it's important to be realistic about how you're likely to feel these first few weeks. Otherwise, you might get discouraged and give up before treatment has a chance to work. Coping with Short-Term Side Effects "When side effects occur, the vast majority arise early in treatment," says Rajnish Mago, M.D., director of the Mood Disorders Program at Thomas Jefferson University in Philadelphia. "Most tend to diminish within a few days or weeks." And although they may be a nuisance, most are not medically dangerous. Side effects vary a bit from one type of antidepressant to another. However, for the more common antidepressants, these are some side effects you may experience early on: Nausea Vomiting Diarrhea Insomnia Headaches Jitters Such side effects tend to lessen with time, but they can be unpleasant while they last. Ask your doctor about ways to reduce the discomfort. For example, taking your medicine after food or in more frequent, smaller doses may reduce nausea and vomiting, while taking it in the morning may reduce insomnia at night. "The initial side effects are usually mild and tolerable," says Prashant Gajwani, M.D., associate professor of psychiatry and behavioral sciences at the University of Texas Health Science Center at Houston. Contact your doctor if you experience side effects that are severe or intolerable, or if you notice sudden, dramatic changes in mood, anger, or agitation. Managing Sexual Side Effects A few side effects may stick around longer. Among the most troubling are sexual side effects, which can affect both men and women. "Difficulty or delay in achieving orgasm is the most common type of sexual dysfunction seen," says Dr. Mago. Other problems may include decreased sex drive and, in men, inability to have an erection. Sexual side effects are more common in people taking selective serotonin reuptake inhibitors (SSRIs). This popular group of antidepressants includes citalopram (Celexa), escitalopram (Lexapro), fluoxetine (Prozac), paroxetine (Paxil), and sertraline (Zoloft). If the problem persists, work with your doctor to find a solution, like lowering your dose or switching to another type of antidepressant, such as bupropion (Wellbutrin). Other Longer-Term Effects Weight gain sometimes occurs as well. "Certain antidepressants, such as paroxetine (Paxil) and mirtazapine (Remeron), are more likely to cause this side effect," Dr. Mago says. "Some of the weight gain may be due to improved appetite or regaining weight lost due to depression." If you're packing on excess pounds, solutions include eating wisely, exercising more, and switching to bupropion. Insomnia is usually a short-term problem, but for some this side effect is lasting. If it continues, your doctor may prescribe a sleeping aid or melatonin supplements. Good sleep habits can make a difference as well. Go to bed and get up at the same time every day. Limit caffeine, especially after noon, and avoid drinking alcohol close to bedtime. Emotional numbness is another complaint that has been linked to SSRIs. You might feel emotionally detached from events that would normally matter to you. Or you might feel emotionally disconnected from other people in your life. Coping strategies include lowering the dose of your SSRI or changing to another type of antidepressant. When Do the Good Effects Kick In? After starting an antidepressant, some people feel their depression lift sooner than others. "Some patients may start to see benefits even in the first week," says Dr. Mago. "More commonly, clear evidence of benefit begins to be seen in two to four weeks." If you aren't feeling any better at all within a month, your doctor may adjust your treatment by changing the dose of your medicine, switching to another medication, or adding psychotherapy or a second medicine to the mix. Even if your antidepressant is working for you, it may take four to eight weeks to feel the full benefit. But it's well worth the wait. As your depression subsides, you may notice "improved energy and concentration, improved sleep, and better overall functioning—for example, in your social life and work performance," says Dr. Gajwani. "You start enjoying things again that you might have lost interest in due to depression." You're back to feeling better, and life is finally looking up. Key Takeaways Give the medicine four to eight weeks to kick in. Take note of any side effects and whether they improve. Talk with your doctor about changing doses or switching medications if side effects are intolerable or you aren't feeling better.