The neuropathological basis for depression in Parkinson's disease

Depression is found in 30-40% of all patients with Parkinson's disease (PD), but its etiology is unclear. Using neuropathology as a signpost for neurotransmitter function. we investigated the prevalence of pathological features found at postmortem and sought to uncover differences between depressed (n = 11) and non-depressed (n = 9) elderly PD patients. The results indicate a higher prevalence of pathological features in depressed compared to non-depressed PD patients, particularly in catecholamine areas of the brain; the locus coeruleus (neuronal loss: odds ratio = 7.2, p = 08; gliosis: odds ratio = 18.0, p = 008); dorsal vagus nerve (gliosis: odds ratio = 7.63, p < 0.05). and substantia nigra pars compacta (gliosis: odds ratio = 2.85, ns). However, neuropathological differences were absent in the dorsal raphe nuclei, amygdala, and cortical regions. Our evidence suggests that depression in PD is related more to catecholaminergic than serotonergic system dysfunction. (C) 2008 Elsevier Ltd. All rights reserved.