Dr. Sbarfstein's Introduction: This month's column discusses the most important change in Medicare coverage for mentally disorders since the inception of Medicare almost 20 years ago. It provides a perspective on the benefits as well as some of the problems in making such a change. One potentially troubling implication of the new policy is that it may lead Medicare to reconceptualize mental conditions with a clearly demonstrable organic etiology as neurologic, rather than psychiatric, conditions. It is important for psychiatry to be recognized as the medical specialty that treats patients with disorders manifested as disturbances of mental processes, bebavior, and emotions. These symptoms and syndromes must be considered independent of etiology, whether it be known central nervous system pathology, developmental problems, psychosocial difficulties, toxic conditions, or otber factors. With this caveat in mind, the following discussion should interest all professionals involved in the treatment of patients with Alzheimer's disease.