Abstract
Parkinson’s disease (PD) is a neurodegenerative disease comprised of motor and non-motor symptoms, including depression and anxiety. The relationship between depression, anxiety, and motor symptoms is not well understood. Additionally, there are few direct comparisons of anxiety and depression between people with PD (PwP) and those without PD. The present study determined differences in state and trait anxiety between those with and without PD, examined the impact of depression on anxiety in both groups, and explored the relationship between depression, anxiety, and motor symptoms among PwP. Data from 42 PwP and 56 non-PD comparison participants were obtained from a non-randomized, non-treatment longitudinal observational study. Anxiety [State-Trait Anxiety Inventory (STAI)], depression (Geriatric Depression Screen), and motor symptoms (Movement Disorder Society - Unified Parkinson’s Disease Rating Scale part III) were assessed. There were no statistically significant differences between PwP and non-PD comparisons for anxiety or depression. Depression was associated with elevated STAI scores (P < 0.001) regardless of PD status. Depressed PwP displayed greater motor symptom burden compared to non-depressed PwP (median [IQR]: 25.00 [21.00, 38.50] vs. 20.00 [16.00, 23.00]; P = 0.064). There were statistically significant differences in both state and trait anxiety when participants were grouped by depression and PD status. While anxiety does not appear to be correlated with motor symptoms in people with PD, depression may be associated with greater motor symptom burden. Further study is needed to explore the relationship between depression, anxiety, and motor impairment in PwP.