The role of serotonin in panic, anxiety and depression.

Anxiety and depressive disorders occur across a broad spectrum, and each different disorder may involve distinct genetic and neurobiologica/neurochemical mechanisms. Many classes of drug are available for the treatment of these disorders and, as might be expected, these drugs exhibit a variety of biochemical actions. Paradoxically, the single-action selective serotonin reuptake inhibitors are effective in a range of these disorders. However, the paradox may be resolved by an understanding of the distinct ways in which serotonin modifies the physiological coping mechanisms that become dysfunctional in these disorders.