SSRIs and SNRIs: broad spectrum of efficacy beyond major depression.

Originally studied and introduced for the treatment of depression, the selective serotonin reuptake inhibitors (SSRIs) and serotonin/norepinephrine reuptake inhibitors (SNRIs) have proven effective for a broad range of psychiatric illnesses, including several anxiety disorders, bulimia, and dysthymia. These drugs have in common important effects on the serotonergic (5-HT) neurotransmission system, which is involved in mediating a substantial number of important functions, including mood, aggression, sexual behavior, and pain. In addition, some of the new antidepressants, like venlafaxine/venlafaxine XR, also have effects on the noradrenergic neurotransmission system, which also appears important in mood and anxiety disorders. These new drugs, because of their specificity for the serotonin and norepinephrine reuptake proteins, lack most of the adverse side effects of tricyclic antidepressants and monoamine oxidase inhibitors. Consequently, in addition to being the usual first-line treatments for major depression, they are also first-line for panic disorder, obsessive-compulsive disorder, social phobia, posttraumatic stress disorder, and bulimia. They may also be the best medication treatments for dysthymia and generalized anxiety disorder. Further advances in psychopharmacology will be driven by discoveries from brain imaging and molecular biological research.