Neuroanatomical correlates of depressive symptoms in newly diagnosed Parkinson’s disease patients

Objective: Depression is the most frequent neuropsychiatric manifestation in Parkinson’s disease (PD). Although evidence suggests that depression in PD is related to the degenerative process that underlies the disease, a complete understanding of neural substrates has yet to be achieved. To investigate the neuroanatomical changes underlying depression in PD, we conducted a surface-based morphometry (SBM) study in de novo, drug-naïve Parkinson’s disease patients with and without depression. Methods: We studied thirty-one patients with idiopathic, de novo, drug-naïve PD. Patient clinical characteristics, including age, sex, disease duration, Hoehn and Yahr stage, UPDRS part III, and brief neuropsychological testing, were assessed. Sixteen Parkinson’s disease patients with depression (PD-D) were defined as patients with abnormal geriatric depressions scales (> 17 points), and fifteen patients had Parkinson’s disease without depression (PD-ND). The SBM analysis of cortical thickness was performed to determine the difference between the PD-D and PD-ND groups. Results: There were no differences in terms of clinical characteristics between the PD-D and PD-ND groups, but the level of education in the PD-ND was higher than that in the PD-D. The cortical thickness was significantly decreased in the left anterior cingulate and left precentral gyrus in the PD-D group compared to the PD-ND group. Conclusion: Depression in Parkinson’s disease is associated with the left anterior cingulate and left precentral gyrus region reduced cortical thickness.