Selective serotonin reuptake inhibitors (SSRIs)

SSRIs, a commonly prescribed type of antidepressant, can help you overcome depression. Discover how SSRIs improve mood and what side effects they may cause.

By Mayo Clinic Staff

Selective serotonin reuptake inhibitors (SSRIs) are the most commonly prescribed antidepressants. They can ease symptoms of moderate to severe depression, are relatively safe and typically cause fewer side effects than other types of antidepressants do.

How SSRIs work

SSRIs ease depression by increasing levels of serotonin in the brain. Serotonin is one of the chemical messengers (neurotransmitters) that carry signals between brain cells. SSRIs block the reabsorption (reuptake) of serotonin in the brain, making more serotonin available. SSRIs are called selective because they seem to primarily affect serotonin, not other neurotransmitters.

SSRIs also may be used to treat conditions other than depression, such as anxiety disorders.

SSRIs approved to treat depression

The Food and Drug Administration (FDA) has approved these SSRIs to treat depression:

  • Citalopram (Celexa)
  • Escitalopram (Lexapro)
  • Fluoxetine (Prozac)
  • Paroxetine (Paxil, Pexeva)
  • Sertraline (Zoloft)
  • Vilazodone (Viibryd)

Fluvoxamine, an SSRI that’s approved by the FDA to treat obsessive-compulsive disorder, is sometimes used to treat depression.

Possible side effects and cautions

All SSRIs work in a similar way and generally can cause similar side effects, though some people may not experience any. Many side effects may go away after the first few weeks of treatment, while others may lead you and your doctor to try a different drug. If you can't tolerate one SSRI, you may be able to tolerate a different one, as SSRIs differ in chemical makeup.

Possible side effects of SSRIs may include, among others:

  • Drowsiness
  • Nausea
  • Dry mouth
  • Insomnia
  • Diarrhea
  • Nervousness, agitation or restlessness
  • Dizziness
  • Sexual problems, such as reduced sexual desire or difficulty reaching orgasm or inability to maintain an erection (erectile dysfunction)
  • Headache
  • Blurred vision

Taking your medication with food may reduce the risk of nausea. Also, as long as your medication doesn't keep you from sleeping, you can reduce the impact of nausea by taking it at bedtime.

Which antidepressant is best for you depends on a number of issues, such as your symptoms and any other health conditions you may have. Ask your doctor and pharmacist about the most common possible side effects for your specific SSRI and read the patient medication guide that comes with the prescription.

June 24, 2016 See more In-depth