An antidepressant is a type of medication that helps alleviate the symptoms of various mental health disorders such as, depression, anxiety disorder, obsessive-compulsive disorder (OCD), panic disorder, serious phobias, such as agoraphobia and social phobia, bulimia, and lastly, post-traumatic stress disorder (PTSD). They try to address chemical imbalances in the brain’s neurotransmitters, which are thought to be the cause of mood and behavioral shifts.