Hypothalamic-pituitary-adrenal axis in psychiatric disorders.

Hypothalamic-pituitary-adrenocortical (HPA) physiology is complex, and dysregulation of this neuroendocrine axis cannot be characterized adequately by isolated or unintegrated measures. Repeated assessments over time, involving multiple measures of axis activity (basal and dynamic tests), have furthered our understanding of the character of the HPA abnormalities reported in various psychiatric disorders. We review the nature and clinical significance of these HPA disturbances in the affective disorders and other psychiatric illnesses.