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 patho physiological mechanisms underlying depression in PD and the interrelation between depression and cognitive decline. (The Journal of Neuropsychiatry and Clinical Neurosciences 1995; 7:281-286) D epression is the most frequent psychiatric disturbance occurring in Parkinson’s disease (PD), with an average prevalence of about 40% (range 25%_70%).1 Many investigators, 5 though not all,6 report an increased prevalence of depression in PD compared with that in normal age-matched subjects, suggesting that PD and depression might share pathophysiological features. Most authors agree that both psychological and biological components play etiological roles in depression. The principal neurobiological substrate in PD is a depletion of dopamine in the striatum,7 but reduced levels of norepinephrine and serotonin have also been demonstrated.8’9 These monoaminergic deficiencies, and particularly the serotonin disturbances, are also thought to play a role in depression. Thus, there seems to be overlap between the pathophysiologies of depression and PD, but the specific relationship is still unclear. Because levodopa does not have a beneficial effect on depression in Parkinson’s disease,1#{176} a better understanding of disturbances in 5-hydroxytryptamine (serotonin) concentrations in PD and in depression might help improve the pharmacological treatment of depression in PD. Antidepressants may diminish the cognitive decline of depressed PD patients.11 The question remains whether only the depressive component of the cognitive