Lexapro is an antidepressant. Its` medicinal compound, Escitalopram, belongs to the group of drugs known as Selective Serotonin Reuptake Inhibitors [SSRIs]. When the neurotransmitter, Serotonin, gets reattached to its` parent nerve in the brain, it results in a chemical imbalance. Escitalopram blocks this reuptake, increasing availability of Serotonin in the brain, thereby setting the imbalance right, and restoring calm. This medicine is used in the treatment of Major Depressive Disorder [MDD], and Generalized Anxiety Disorder [GAD].