It has long been recognized that disturbances of the thyroid, such as cretinism, myxœdema and some cases of Graves's disease, can give rise to mental symptoms. Of recent years, however, other endocrinopathies have been investigated from the psychological standpoint, and in nearly all cases evidence of some abnormality has been found. For example, Werner (1) examined 53 castrates, 48 cases of involutional melancholia, and 96 women of menopausal age, and found marked similarity between the mental symptoms occurring at the menopause and those in involutional melancholia, and presumed that they were both due to the same cause—ovarian dysfunction.