Sertraline is used to treat depression, obsessive-compulsive disorder (bothersome thoughts that won’t go away and the need to perform certain actions over and over), panic attacks (sudden, unexpected attacks of extreme fear and worry about these attacks), posttraumatic stress disorder (disturbing psychological symptoms that develop after a frightening experience), and social anxiety disorder (extreme fear of interacting with others or performing in front of others that interferes with normal life). It is also used to relieve the symptoms of premenstrual dysphoric disorder, including mood swings, irritability, bloating, and breast tenderness. Sertraline is in a class of antidepressants called selective serotonin reuptake inhibitors (SSRIs). It works by increasing the amounts of serotonin, a natural substance in the brain that helps maintain mental balance.
Sertraline comes as a tablet and a concentrate (liquid) to take by mouth. It is usually taken once daily in the morning or evening. To treat premenstrual dysphoric disorder, sertraline is taken once a day, either every day of the month or on certain days of the month. Take sertraline at around the same time every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take sertraline exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.
Summary from MedlinePlus.gov, click for more information.