lexapro - Version 1.0 This medicine is a selective serotonin reuptake inhibitor or SSRI used to treat depression and generalized anxiety disorder (GAD). It may also be used to treat other conditions as determined by your doctor. Lexapro is unique in that it was created based on an advanced technique. Lexapro was developed by isolating the medicinal component of CELEXAR (citalopram HBr), a molecule known as an isomer. Lexapro is from the family of drugs known as selective serotonin reuptake inhibitors or SSRIs. Lexapro helps to restore the brain's chemical balance by increasing the supply of a chemical messenger in the brain called serotonin. Lexapro appears to relieve the symptoms of depression and anxiety by increasing serotonin with minimal effect on many of the other chemicals in the brain.