[Parkinson's disease as a neuropsychiatric disorder]

Parkinson's disease has previously been described as a disorder involving the triad of tremor, bradykinesia and rigidity. Hence its current classification as a movement disorder. Over recent decades, more emphasis has been placed on the so-called non-motor symptoms, which comprise autonomous nervous symptoms, cognitive dysfunction and psychiatric symptoms, such as depression, anxiety, apathy, impulse disorders, hallucinations and psychosis. These latter groups of symptoms can precede disease onset, determine the patient's well-being to a large extent and may provide valuable biomarkers for early diagnosis, treatment response and prognosis. Hence, we propose that Parkinson's disease be classified as a neuropsychiatric disorder.