Preliminary examination of the comorbidity of anxiety and depression in Parkinson's disease

Significant anxiety in combination with depression may represent a specific depressive subtype in Parkinson's disease (PD). To ascertain the prevalence of this symptom complex, we administered a self-report survey and standardized psychological tests that measure anxiety and depression to 164 PD patients and 150 age-matched healthy spouse control subjects. The reporting of depression in combination with panic/anxiety best differentiated the two populations (38% vs. 8%). Depression and anxiety were highly correlated in relationship to clinical features of PD. Our findings suggest that clinically significant levels of depression and anxiety may frequently coexist in PD. The specific neuropathology of PD may predispose to this pattern of behavioral disturbance.