Paroxetine is an antidepressant in a group of drugs called selective serotonin reuptake inhibitors (SSRIs). Paroxetine affects chemicals in the brain that may become unbalanced. Paroxetine is used to treat depression, obsessive-compulsive disorder, anxiety disorders, post-traumatic stress disorder (PTSD), and premenstrual dysphoric disorder (PMDD). The Brisdelle brand of paroxetine is used to treat hot flashes related to menopause. Brisdelle is not for treating any other conditions. Paroxetine may also be used for purposes not listed in this medication guide.