Increased depressive symptoms in Parkinson's disease during the COVID-19 pandemic: Preliminary findings from longitudinal analysis of the PHASE study

Introduction: The cumulative number of patients has increased through the four waves of the pandemic in Japan. Many people experienced mental stress due to the fear of infection, and restrictions of leaving the house and leisure activities. No longitudinal study has assessed the fluctuation of neuropsychiatric symptoms during the COVID-19 pandemic using the same scale. We examined changes in non-motor symptoms, and the scores of a Parkinson's Disease (PD)-specific questionnaire between the early and later periods during the COVID-19 pandemic.Methods: We conducted a questionnaire survey during the first wave (from February to April 2020) and the fourth wave of the COVID-19 pandemic (from March to April 2021). We compared the number of symptoms from the two periods.Results: Compared with the first wave, the Geriatric Depression Scale score was significantly higher in the fourth wave of the pandemic (median score of GDS: 4.00 vs. 5.50, p = 0.022). Consistently, the scores of symptoms on MDS-UPDRS part 1 in the fourth wave were significantly higher in hygiene (p = 0.033), handwriting (p = 0.033), performing hobbies and other activities (p = 0.035), and turning in bed (p = 0.046) than in the first wave. Conclusions: Our observation over a year between the early and later phases of the COVID-19 pandemic showed an increase in the severity of depression in patients with PD.