Estrogens in Neuropsychiatric Disorders: From Physiology to Pathophysiology -- Estrogens and Schizophrenia -- Gender Differences in Schizophrenia -- Puberty and Schizophrenia Onset -- Clinical Estrogen Trials in Patients with Schizophrenia -- Hypoestrogenism and Estrogen Replacement Therapy in Women Suffering from Schizophrenia -- The Effect of Estrogens on Depression -- Estrogens and Other Hormones in the Treatment of Premenstrual Syndromes -- Estrogens and Perinatal Disorders -- Estrogen Therapy in Perimenopausal Affective Disorders -- The Effects of Estrogens on Cognition and Alzheimer's Dementia -- Effects of Hormone Therapy on Patterns of Brain Activation during Cognitive Activity: A Review of Neuroimaging Studies -- Estrogens in Alzheimer’s Disease: A Clinical and Neurobiological Perspective -- Estrogen Therapy: Interface Between Gynecology and Psychiatry.A number of studies, mostly focusing on estrogen replacement therapy in women, have reported beneficial actions of these hormones on various neurobiological and neuropathological parameters in health and disease. Recent research has focused on gender differences and there is increasing evidence that estrogens exert protective effects in schizophrenia. Hormonal fluctuations or lack of estrogen may increase the risk of depression among vulnerable women. Treatment of depression with estrogen may stabilize and restore disrupted homeostasis – as during post-partum, premenstrual, or perimenopausal conditions – and act as a psychomodulator to offset vulnerability to dysphoric mood when estrogen levels are significantly decreased, as in the case of postmenopausal women. Studies on the effect of estrogens on Alzheimer’s Disease are still rather controversial, they do, however, facilitate the hypothesis that estrogens may have a modifying effect on the onset and course of AD, at least in subgroups of patients.