Depression in Parkinson's disease

Abstract

Depression is one of the most common non-motor symptoms in Parkinson's disease (PD) affecting 30–40% of patients and it has a major impact on quality of life. Depressive features in PD, however, overlap with core features of PD such as apathy, anhedonia, sleep–wake dysregulation, and lack of energy. Depressive symptoms in PD have been correlated with multiple neurotransmitter abnormalities in the parkinsonian brain including dopaminergic and noradrenergic denervation of parts of the limbic system and ventral striatum as well as loss of serotonergic brainstem neurons. Overall there are limited data from controlled clinical trials assessing interventions that target depression in PD. Recent studies have provided further evidence for antidepressive efficacy of dopaminergic therapies, in particular dopamine agonists. However, to date no placebo-controlled study has unequivocally established the efficacy of any dopaminergic agent or antidepressive drug specifically against depression in PD. From a pragmatic point of view tricyclic antidepressants and selective serotonin reuptake inhibitors (SSRIs) continue to be the most frequently used antidepressant treatments in routine clinical practice, while, so far, few data are available for the new mixed serotonergic and noradrenergic antidepressants reboxetine, mirtazapine, venlafaxine, and nefazodone.