Fatigue in Parkinson's disease: a nine-year follow-up.

Fatigue affects about 50% of Parkinson's disease (PD) patients and is frequently one of its most disabling aspects. It does not correlate with disease severity or duration but does correlate with depression. Fatigue and depression are distinct symptoms and fatigue often fails to respond to antidepressants. The natural history of fatigue in PD is unknown, as no longitudinal studies have been published. This report describes the follow-up of subjects from our original study performed 9 years ago. Fatigue was a persistent problem for our subjects. Copyright 2001 Movement Disorder Society.