Treatment of depression in Parkinson's disease: a meta-analysis.

Despite a 40% prevalence of depression in idiopathic Parkinson's disease (PD), an extensive literature search found only 12 controlled studies of treatment efficacy. A meta-analysis of these was performed in pursuit of guidelines for pharmacological treatment. Articles were scored on a scale from 0 to 100 on a specially adapted list of methodological criteria. Only 4 articles scored more than 50 points, and these generally did not use depression rating scales. Thus, there are virtually no empirical data on the treatment of depression in PD. Further studies are urgently needed, both for the sake of patient care and to gain a better understanding of the pathophysiological mechanisms underlying depression in PD and the interrelation between depression and cognitive decline.