Neuropsychiatry of Parkinson's disease.

Parkinson's disease (PD) is traditionally regarded as a movement disorder. In recent years, however, non-motor symptoms have been considered significant factors of disability at all stages of the illness. Behavioral and psychological symptoms or neuropsychiatric syndromes associated with PD are frequent and may represent a challenge in the management of these patients. They include anxiety, depression, psychosis, sleep, sexual and impulse control disorders, apathy and cognitive dysfunction. Their pathogenesis in PD is complex, involving neurodegenerative, drug-related and psychological mechanisms. We will review the current knowledge of this growing field, also focusing on the management of theses syndromes.