Depression and Parkinson's disease: a new look at an old problem.

A National Institutes of Health (National Institute of Neurological Disorders and Stroke; National Institute of Mental Health; National Institute on Aging) working group meeting focused on the non-motor aspects of Parkinson's disease (PD). Below is the summary of the meeting presentations and recommendations for a research agenda on the epidemiology, assessment, circuitry, therapeutic approaches, and clinical trials of Parkinson's disease co-morbid with depression. A second summary will focus on PD and dementia. Copyright 2002 Wiley-Liss, Inc.