Emotional and cognitive disorders are common in Parkinson's disease, but are frequently overlooked or undertreated. This book provides a comprehensive account of these aspects of Parkinson's disease, based on the neurological and psychiatric assessment of hundreds of patients by the authors. It also offers a thorough survey of the published literature on the topic. Readers will find a complete and helpful overview of the clinical features and treatment of Parkinson's disease, followed by discussion of associated depressive disorders, anxiety, phobias, apathy, hallucinations, delusions and sleep disorders. Specific cognitive deficits are also discussed, and the mechanisms for these disorders explored. The book also addresses the psychiatric and cognitive side effects of anti-parkinsonian medications and surgical treatments. Offering sufficient scientific detail for the specialist in neurology and psychiatry, the clear practical guidelines, case studies and rating scales will meet the needs of all clinicians working with Parkinson's disease patients.