Non-motor aspects of Parkinson's disease

The neuropsychiatric symptoms are a frequent feature of advancing Parkinson's disease (PD) and have been considered significant factors of disability at all stages of the illness. 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. These non-motor symptoms of PD are under-reported, unrecognized, untreated by physician and are a key determinant of quality of life. Even when identified, there is a common perception that many of these symptoms are untreatable. This article focuses on the issues related to the recognition and treatment of nonmotor comorbidities of PD in routine clinical settings.