Lexapro - Lexapro is a prescription medicine for the treatment of depression and generalized anxiety disorder (GAD) in adults. Just like diabetes, heart disease, or asthma, these are real medical conditions that require diagnosis and treatment from a medical professional. Depression and GAD can be caused by an imbalance of certain chemicals in the brain. Lexapro is an antidepressant and a member of the family of medicines known as selective serotonin reuptake inhibitors (SSRIs).