• Depression

All about antidepressants

Effectiveness and side effects vary

Antidepressants differ in their side effects and effectiveness in treating each individual, but the majority of people with depression can be treated effectively by one of these medications.

Antidepressants work to normalize naturally occurring brain chemicals called neurotransmitters, notably serotonin and norepinephrine. Some antidepressants work on the neurotransmitter dopamine. Scientists studying depression have found that these particular chemicals are involved in regulating mood, but they are unsure of the exact ways in which they work.

The newest and most popular types of antidepressant medications are called selective serotonin reuptake inhibitors (SSRIs). SSRIs include fluoxetine (Prozac), citalopram (Celexa), sertraline (Zoloft) and several others. Serotonin and norepinephrine reuptake inhibitors (SNRIs) are similar to SSRIs and include venlafaxine (Effexor) and duloxetine (Cymbalta). SSRIs and SNRIs are more popular than the older classes of antidepressants, such as tricyclics–named for their chemical structure–and monoamine oxidase inhibitors (MAOIs) because they tend to have fewer side effects. But for some people, tricyclics or MAOIs may be the best choice. MAOIs interact with some foods and medications, which your doctor will discuss with you.

Other newer medications chemically unrelated to the other antidepressants are bupropion (Wellbutrin) and mirtazapine (Remeron). Mirtazapine is notorious for causing weight gain, but bupropion, now available as a once-daily generic, has not been associated with this or the other common problem of the SRI’s: decreased sexual interest and performance. Bupropion also has one of the lowest risks of discontinuation “withdrawal” symptoms. In Why isn’t bupropion the most widely prescribed antidepressant? an article in the Journal of Clinical Psychiatry, several well-known mood experts found that some doctors believe it may not have as much anti-anxiety effect as the SSRI’s. “If you have anxiety symptoms, your doctor may consider another option,” says psychiatrist Jim Phelps, author of Why Am I Still Depressed?

Medications affect everyone differently–no one–size–fits–all approach to medication exists. If one does not work, be open to trying another. Studies have shown that patients who did not get well after taking a first medication increased their chances of becoming symptom–free after they switched to a different medication or added another medication to their existing one. For all classes of antidepressants, patients must take regular doses for several weeks before they are likely to experience a full therapeutic effect. They should continue taking the medication for the time specified by their doctor, even if they are feeling better, in order to prevent a relapse of the depression. Some medications need to be gradually stopped to prevent withdrawal symptoms or a relapse. Some individuals, such as those with chronic or recurrent depression, may need to stay on the medication indefinitely.

Side effects

Antidepressants may cause side effects in some people, but many side effects are temporary. However, any unusual reactions or side effects that interfere with normal functioning should be reported to a doctor immediately.

Side effects of antidepressants can include:

  • reduced sexual drive or performance
  • nervousness
  • sleeping problems
  • drowsiness, fatigue
  • nausea
  • dry mouth
  • constipation
  • dizziness
  • agitation, restlessness, anxiety
  • increased appetite, weight gain