What Are Antidepressants?

Antidepressants are a drug class that balance certain chemicals in the brain that affect mood and behavior.

Medically Reviewed

Antidepressants are prescription drugs used to treat different types of depression. They work by moderating certain chemicals in the brain that affect mood and behavior.

These medicines were first developed in the 1950s, according to research. Today, the Centers for Disease Control and Prevention (CDC) estimates that about 13 percent of American adults take an antidepressant.

The medicines are used to treat a variety of conditions, including:

It can take several weeks for antidepressants to begin to work. Antidepressants are typically taken for months or years at a time.

There are several different classes of antidepressants, according to StatPearls. These include:

Common Antidepressants

There are many antidepressants on the market. Some of these include:

Antidepressant Side Effects

Per StatPearls, antidepressants can cause side effects, including:

Antidepressants are required to carry a black-box warning about the potential for suicidal thoughts and behaviors, per the U.S. Food and Drug Administration.

In some short-term studies, the medicines increased the risk of suicidal tendencies in some children and young adults with depression or psychiatric disorders. These effects were most pronounced in the weeks after starting on a course of antidepressants, or when increasing the dosage, according to a review of related studies. But the researchers also noted that there is no clear consensus among clinicians about this risk, given the corresponding potential risks of not prescribing medication to patients in need.

An analysis published in the journal BMJ also found that the use of antidepressants can double the risk of aggressive behavior and suicide in children.

Additionally, you may experience unpleasant withdrawal symptoms if you stop taking an antidepressant suddenly — although you should never stop taking antidepressants without consulting with your doctor first.

Talk to your doctor about these potential effects and how to minimize withdrawal symptoms or avoid them entirely.

Antidepressants and Weight Gain

Weight gain is another common side effect of antidepressants.

Some studies show up to 25 percent of people who take these medicines gain a significant amount of weight.

You can minimize this unwanted effect by exercising and following a healthy eating plan.

Since some antidepressants are more likely to lead to weight gain than others, talk to your doctor about switching to another medication if the antidepressant you are taking seems to be causing your weight problems.

Antidepressants and Pregnancy

Taking an antidepressant during pregnancy may cause risks for an unborn baby, but for some pregnant women, not treating depression poses risks, too.

Talk to your doctor about the benefits and risks of taking antidepressants during pregnancy.

Some antidepressants do enter breast milk, but there is no conclusive evidence that this is harmful to a breastfeeding infant.

Nevertheless, talk to your doctor about the risks and benefits of taking an antidepressant if you are breastfeeding.

Antidepressants and Alcohol

Drinking alcohol while taking an antidepressant can worsen your symptoms and increase your risk of certain side effects, notes the Mayo Clinic.

Talk to your doctor about the potential interaction between alcohol and antidepressants.

Editorial Sources and Fact-Checking

  • Pereira VS, Hiroaki-Sato VA. A Brief History of Antidepressant Drug Development: From Tricyclics to Beyond Ketamine. Acta Neuropsychiatrica. December 2018.
  • Antidepressant Use Among Adults: United States, 2015–2018. Centers for Disease Control and Prevention. September 4, 2020.
  • Sheffler ZM, Patel P, Abdijadid S. Antidepressants. StatPearls. May 26, 2023.
  • Suicidality in Children and Adolescents Being Treated With Antidepressant Medications. U.S. Food and Drug Administration. February 5, 2018.
  • Dwyer JB, Bloch MH. Antidepressants for Pediatric Patients. Current Psychiatry. September 2019.
  • Sharma T, Guski LS, Freund N, Gøtzsche PC. Suicidality and Aggression During Antidepressant Treatment: Systematic Review and Meta-Analyses Based on Clinical Study Reports [PDF]. BMJ. January 27, 2016.
  • Antidepressants and Alcohol: What’s the Concern? Mayo Clinic. June 9, 2017.
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