The hypothalamic-pituitary-adrenal (HPA) axis has undoubtedly received more psychobiologic scrutiny than any other endocrine axis. Historically, one rationale for the intensive study of adrenocortical function in patients with primary psychiatric disorders was the observation that patients with primary endocrine disorders such as Addison's disease or Cushing's syndrome exhibited a higher than expected psychiatric morbidity. The most intensive scrutiny of the HPA axis has been conducted in patients with major depression. Cushing's syndrome, due to prolonged exposure to excessive Cortisol or other related glucocorticoids, is accompanied by psychiatric symptoms of anxiety and/or depression that generally remit with diminution of abnormal glucocorticoid concentrations. Despite the higher incidence of depression in women than men and the purportedly increased occurrence of depression during and after menopause, the hypothalamic-pituitary-gonadal (HPG) axis has received relatively little scrutiny in patients with mood disorders.