SSRI (Selective Serotonin Reuptake Inhibitor)
A common first-line class of antidepressant medication.
SSRIs (sertraline, escitalopram, fluoxetine, etc.) increase serotonin available in the brain. They treat depression, anxiety, OCD, and PTSD. Most people see partial benefit in 2-4 weeks and full effect by 8-12 weeks; common early side effects are nausea, headache, and sleep changes.
Medically reviewed by Dr. Ikechukwu Ogbu, MD
MD · Board-Certified, Internal Medicine · Last reviewed June 2026