Dr. Margaret Altemus has a longstanding interest in neuropeptide and neurohormonal systems in both normal stress responses and in the pathophysiology of anxiety and affective disorders. She also studies the potential role of these systems in the mechanism in action of antidepressant and anti-anxiety medications. Methods for investigating these relationships include measures of gene expression and endocrine, physiological, and behavioral measures.Studies are conducted in healthy humans, patients with anxiety disorders, and in animal models. Dr. Altemus has several studies currently in progress and enrolling new subjects. 1) A study of the effects of pregnancy and lactation on the course of anxiety disorders; 2) a treatment study to test whether an androgen hormone blocker can relieve the symptoms of premenstrual dysphoric disorder; and 3) a treatment study to test whether an adrenergic receptor blocker can relieve the symptoms of PTSD.