Alzheimer's disease (AD) is now recognized as a major cause of morbidity and mortality in elderly populations throughout the world. Tragically, no clearly effective treatment for this major illness entity has emerged. In part, the lack of an effective treatment is the result of an absence of fundamental knowledge regarding the etiology and pathogenesis of the illness. However, treatment implies the amelioration of symptoms, not cure. In other neuropsychiatric illnesses such as schizophrenia, major depression, and idiopathic Parkinson's disease, there is a similar absence of knowledge regarding etiology and, to a greater or lesser extent, regarding pathogenesis. Nevertheless, symptomatic treatment for these other neuropsychiatric illnesses is available. The same potential for symptomatic treatment exists in AD. The absence of consensus or systematic information regarding treatment in AD is in large part due to the failure to apply appropriate methodologies to symptomatic assessment and pharmacologic treatment.