Many psychiatric conditions result from disturbances in the chemical processes of the body—that is, disturbances of metabolism. Disorders of this kind frequently produce changes in brain function of either an acute or chronic character and may lead to a wide variety of personality disturbances. They are classified by the American Psychiatric Association (1952) under acute brain syndrome associated with metabolic disturbance or chronic brain syndrome associated with disturbance of metabolism, growth, or nutrition Psychiatric disorders resulting from metabolic disturbances fall into the following groups: (1) endocrine disorders involving the thyroid, pituitary, adrenal, or parathyroid glands (see thyroid GLAND, MYXEDEMA, VIRILISM, ACROMEGALY, FROHLICH’S SYNDROME, ADDISON’S DISEASE, HYPOCALCEMIA, CUSHING’S SYNDROME; (2) nutritional deficiencies (see STARVATION REACTIONS, PELLAGRINOUS PSYCHOSIS, DEHYDRATION REACTIONS, DIABETIC REACTIONS, BERI BERI, WERNICKE’S SYNDROME, KORSAKOFF’S SYNDROME, HYPOGLYCEMIA, HYPOGLYCEMIC STATES; and(3) other metabolic disorders (see porphyria, POSTPARTUM PSYCHOSIS, POSTOPERATIVE DISORDERS, EXHAUSTION DELIRIUM, HEPATOLENTICULAR DEGENERATION, ALZHEIMER’S DISEASE. In general, metabolic disorders produce psychological symptoms that range from mild changes in feeling and attitude to serious mental illness. These changes are related not only to the physical disorder but to the basic personality of the patient. A well-integrated individual can usually withstand the stress of metabolic disturbance far better than a marginally adjusted person. A neurotic reaction or a frank psychosis may be precipitated in predisposed patients, and cannot be eliminated simply by correcting the physical disorder.Many types of factors are involved in producing these psychiatric conditions. In endocrine disorders there is a constant interaction between physical and psychological factors, and it has been found that the same type of hormonal change will vitally affect the emotional life of one individual and have little influence upon another. If the glandular condition brings about gross changes in the “body image”—for example by producing masculine features in a young woman—the patient is almost bound to be emotionally disturbed. See BODY IMAGE.Nutritional deficiencies and other metabolic disorders generally have a depressive effect on body functions, and this may lead to a wide variety of psychological symptoms. Among these are apathy, irritability, anxiety, and in extreme cases, confusion, delirium, and stupor. The nature and extent of postoperative disturbances depend not only on toxic and infectious complications, but on the attitudes of the patient toward the affected organ. Postpartum reactions have been found to depend as much upon the personality of the patient, her adjustment to married life, and her attitude toward having a child as upon the metabolic and other physical factors involved in childbirth. For mental deficiency associated with metabolic disorders,