Neuropeptides: relevance in treatment of depression and anxiety disorders

The etiology and pathophysiology of both depression and anxiety remain unclear, but involve dysfunctional monoaminergic neurotransmission and function. The currently available antidepressant medications that work through optimizing the monoaminergic system are often limited by their lack of efficacy or their adverse effects. There is increasing evidence that some neuropeptides, including substance P, corticotropin-releasing factor, neuropeptide Y, vasopressin and galanin, may have relevance in both depression and anxiety. Integration of anatomical, physiological and clinical evidence suggests that modulation of monoaminergic transmission is the most likely mechanism by which neuropeptides may work in these disorders. These neuropeptides and their receptors may serve not only as potential therapeutic targets for treatment of depression and anxiety, but may also help enhance our understanding of the psychopathology of these two major psychiatric disorders.