In recent decades, medical research has begun to delineate some of the physiological phenomena associated with the various mental disorders. Genetic, biochemical, and anatomic investigations increasingly indicate that psychiatric disease is a medical problem resulting through physiologic mechanisms. Of the different processes that could be involved, neurotransmitter imbalances have received considerable scrutiny. Altered levels of norepinephrine, dopamine, and serotonin may be responsible for such diseases as schizophrenia and depression. This obviously emphasizes medical treatments as the most appropriate therapy for these disorders. Regardless though, psychiatric health care providers continue to widely utilize psychological interventions. One such treatment, dynamic psychotherapy, dates back to the time of Freud. In contrast, other psychological techniques (i.e., the cognitive-behavior therapies) have been developed more recently. Although these interventions may be popular with both patients and therapists, their relative effectiveness remains uncertain. The human brain is both complex and inaccessible. These characteristics have made it extremely difficult to study. While the known mental disorders have generally been described in terms of course and symptoms, their etiologies have, for the most part, remained obscure (Kety, 1982, p. 94). Only during the last 20 years have the involved underlying physiologic processes begun to be elucidated (Brown & Mann, 1985, p. 141).
For example, various investigations have attempted to determine whether or not mental disorders are inherited. Several classical studies examined the incidence of schizophrenia among the relatives of schizophrenic patients. It was found that among siblings and offspring, the risk is between 10 and 15%. In fact, the offspring of two schizophrenic parents have a 30-40% risk of developing the disease (Kety, 1982, p. 94). Moreover, schizophrenia...