A selective serotonin reuptake inhibitor (SSRI) is a type of antidepressant medication. SSRIs are the most commonly prescribed antidepressants because they tend to have few side effects. Check out examples of SSRIs, the conditions they treat, the side effects they can cause, and other factors to help you decide if an SSRI might be a good choice for you.

SSRIs are often used to treat depression. However, they may also be used to treat many other conditions. These conditions may include:

Anxiety is often treated with SSRIs. Some SSRIs are approved by the Food and Drug Administration (FDA) specifically for this purpose. These include escitalopram, paroxetine, and sertraline. That said, all SSRIs may be used off-label to treat anxiety.

Read more: Other drugs to treat anxiety disorder »

Serotonin is one of many brain chemicals that transmit messages between brain cells. It has been called the “feel-good chemical” because it causes a relaxed state of well-being. Normally, serotonin circulates in the brain and then absorbs into the bloodstream.

Depression is linked with low levels of serotonin (as well as low levels of dopamine, norepinephrine, and other brain chemicals). SSRIs work by preventing your blood from absorbing some of the serotonin from your brain. This leaves a higher level of serotonin in the brain, and increased serotonin can help relieve depression.

SSRIs don’t cause the body to make more serotonin, however. They simply help the body use what it has more effectively.

SSRIs are fairly similar in terms of how effective they are. They do vary slightly in what they’re used to treat, their side effects, their dosage, and other factors.

There are a number of SSRIs available today. These include:

  • citalopram (Celexa)
  • escitalopram (Lexapro)
  • fluoxetine (Prozac, Sarafem)
  • fluvoxamine (Luvox)
  • paroxetine (Paxil, Paxil XR, Pexeva)
  • sertraline (Zoloft)

Side effects vary among the SSRIs. Possible side effects include:

  • nausea
  • dry mouth
  • headache
  • trouble sleeping
  • tiredness
  • diarrhea
  • weight gain
  • increased sweating
  • rash
  • nervousness
  • sexual dysfunction

Doctors often prescribe SSRIs before other antidepressants because they typically have fewer side effects. That is, SSRIs are generally safe.

“Selective serotonin reuptake inhibitors are very safe drugs, generally speaking,” says Danny Carlat, MD, Associate Clinical Professor of Psychiatry at Tufts University School of Medicine. “While there are some pretty minor side effects, it would be very hard for people to do any damage to themselves by taking an SSRI.”

That said, certain people should be cautious about using an SSRI. These include children and pregnant women.

For children

In 2004, the FDA added a black box warning to drug labels for SSRIs. The warning describes an increased risk of suicidal thoughts and behavior in children and adolescents. However, further studies have suggested that the benefits of antidepressant medication may outweigh the risks of these suicidal thoughts.

For pregnant women

SSRIs increase the risk of certain birth defects, especially heart and lung problems. Doctors and moms-to-be must compare the risks of SSRI treatment to the risks of untreated depression. Depression without treatment can also have a negative impact on a pregnancy. For instance, depressed women may not seek the prenatal care they need.

Some pregnant women may switch their SSRI to reduce their risk while still treating their depression. This is because different SSRIs have different side effects. For instance, Paroxetine (Paxil) is linked with fetal heart defects as well as trouble breathing and brain disorders in the newborn. Doctors of women taking paroxetine may suggest they switch to fluoxetine (Prozac) or citalopram (Celexa) when they become pregnant. These SSRIs aren’t linked with such serious side effects.

Read more: Risk to your child of depression during pregnancy »

If you think an SSRI might work well for you, talk with your doctor. They will review your health history with you and help decide if an SSRI could treat your condition. Some questions you might want to ask your doctor include:

  • Am I at high risk of side effects from an SSRI?
  • Do I take any medications that might interact with an SSRI?
  • Is there a different type of medication that might work better for me?
  • Would talk therapy be a good option for me instead of medication?
  • How long will it take for an SSRI to start working?
  • Can I stop taking my SSRI if my depression gets better?