Frequency of psychiatric disorders in young-onset Parkinson's disease does not differ from typical-onset Parkinson's disease.

Psychiatric disorders are very common in Parkinson's disease (PD). Whether these disorders are more prevalent in young-onset or typical-onset PD remains a matter of debate. The objective of this study was to assess systematically and to compare the range of psychiatric disorders between 50 patients with young-onset PD and 40 patients with typical-onset PD. Despite both groups having presented a remarkably high occurrence of psychiatric disorders, their frequencies did not differ.