Cortical thinning in drug-naive Parkinson's disease patients with depression.

To shed more light on the contribution of brain structural changes to PD-related depressive symptoms, this study conducted cortical thickness analysis in drug-naive PD patients with and without depression. We recruited 27 PD patients with depression (PD-Dep), 29 PD patients without depression (PD-NDep), and 56 normal controls. T1 weighted magnetic resonance imaging and surface-based morphometric analyses were performed to examine morphometric abnormalities in PD patients and their relationship to depression. We found decreased thickness in the left prefrontal cortex in PD-Dep group compared with PD-NDep group. No significant difference was found between PD patients and controls. In addition, we found there is a trend of inverse correlation between the structural changes and the score of depressive symptom in depressed PD patients. This study demonstrates that cortical thinning in prefrontal area in drug-naive PD patients with depression and highlights the critical role of prefrontal region in the depression associated with PD.