Depression is twice as common among patients with Parkinson’s disease (PD) than it is among healthy individuals, and treating the symptoms of depression could help improve the quality of life of patients. A better understanding of the factors associated with depression can lead to a focused screening and clinical examination/interview of this patient population.
This study enrolled 93 adult patients with idiopathic PD aged ≥ 55 years. The severity of depression was classified as follows using the Geriatric Depression Scale (GDS) score: No depression (GDS, 0-9), mild depression (GDS, 10-19), and severe depression (GDS, 20-30). Stepwise logistic regression was then used to evaluate the relationships between baseline clinical factors and the presence of depression (both mild and severe depression), after adjusting for potential confounding factors.
In total, 73 (78%) patients with PD were diagnosed with depression (mild depression, n=51; severe depression, n=22). Clinical factors associated with the risk of depression were sex, years of education, exercise habituation, miniâÂÂÂÂmental state examination (MMSE) scores, mean levodopa equivalent dose, and mean Barthel index, unified Parkinson’s disease rating scale (UPDRS) score, striatal dopamine transporter uptake ratios, and Hoehn and Yahr staging. Of these risk factors, both female sex and mean UPDRS score remained independently associated with the risk of depression in the stepwise logistic regression analysis. Women had an odds ratio of 3.6 compared to that of men, and the cut-off value of the mean UPDRS score for predicting the risk of depression was 38.5 (sensitivity, 75%; specificity, 76.5%).
Higher mean UPDRS score (>38.5) and female sex are associated with a higher risk of depression. The prevention and evaluation of depressive disorders in the high-risk PD group are important safety issues and are highly relevant to patients’ quality of life.