Behavioral symptoms are an integral part of Parkinson's disease. In the past decade there has been an enormous amount of research on the nature of these disturbances, their underlying neural basis, and methods of assessment. This book provides an up-to-date review of neuropsychological deficits, depression, and treatment-related behavioral disorders associated with Parkinson's disease. Each section is a balanced presentation of both theoretical and practical issues. From a theoretical perspective, study of the neurobehavioral features of Parkinson's disease has contributed to our understanding of the subcortical structures and neurotransmitter systems related to human cognitive and emotional functions. From a practical perspective, behavioral symptoms represent a major treatment challenge. The advent of levodopa has created a population of older and more chronically disabled Parkinson patients, and has made it more imperative to understand the illness. Proper management of patients requires adequate methods for assessing behavioral changes, understanding the relationship of the behavior to the neurobiology of the disease, and being aware of therapeutic options.