Evaluation of the determinants and neuroanatomical associations of the depression that is comorbid with i?diopathic parkinson's disease

Major depression is frequently comorbid with Idiopathic Parkinson?s disease (IPD) and the psychosocial and neurobiologic aspects of this comorbidity are not well-known. In this study, 55 IPD patients were evaluated wıth SCID-I, sociodemographic data form and other clinical scales, in order to measure depression frequency and its related factors. After the evaluation, 7 IPD patients that had a comorbid depression were matched with 7 IPD patients that did not have a comorbid depression, for age, gender, educational status, UPDRS III scores and duration of IPD symptoms and in order to examine the neuroanatomical relationship of depression, two groups were compared for gray and white matter volumes using voxel based morphometry analysis and for task related activations using emotional stroop functional magnetic resonance imaging. It has been found that the diagnosis of life time depression (% 45.5), depression in the last month (%25.5) and depression before IPD diagnosis is common and the major determinants of having a depression diagnosis are early IPD onset and young patient age. Compared to IPD patients that did not have a comorbid depression, IPD patients that had a comorbid depression showed significant differences in gray and white matter of several frontal gyrus and temporal gyrus regions, but no difference in striatal structures and anterior cingulate were found. In IPD patients that had a comorbid depression, right medial frontal cortex had both decreased gray matter volume and decreased activation during emotional stroop task. This study points out that depression is frequently comorbid in IPD and that depression in IPD may have different neurobiological correlates compared to the depression in the general population. Further studies with larger sample sizes are needed to replicate the results of this study.