A consecutive series of 94 patients with Parkinson's disease (PD) were
evaluated for the presence of depression and neuropsychological deficits.
Patients were divided into groups based on the severity of their PD
symptoms and then further subdivided into depressed and nondepressed
groups. Both stage of PD and existence of depression had significant
effects on neuropsychological performance. The nondepressed group with
severe symptoms showed deficits in cognitive tasks involving motor speed,
and the depressed patients with severe symptoms demonstrated impairments in