Changes in Principal Caregiver Mood Affects the Mood of the Parkinson’s Disease Patient: The Vicious Cycle of Illness

Background: Although many studies have analyzed what factors contribute to caregiver burden in Parkinson’s disease (PD), there is currently no knowledge about how the status of the caregiver could impact the patient. Objective: The aim of this study was to analyze how the change in the caregiver’s status influences PD patients. Methods: PD patients and their caregivers who were recruited from January/2016 to November/2017 from 35 centers in Spain from the COPPADIS cohort were included in the study (V0). They were evaluated again at 2-year follow-up (V2). Caregivers completed the Zarit Caregiver Burden Inventory (ZCBI), Caregiver Strain Index (CSI), Beck Depression Inventory-II (BDI-II), and EUROHIS-QOL 8-item index (EUROHIS-QOL8) at V0 and V2. Multivariate models were used to analyze the impact of the change from V0 to V2 () on the caregiver’s status over the change in the patient’s status. Results: BDI-II and EUROHIS-QOL8 in the caregiver predicted BDI-II ( = 0.32; p < 0.0001; R2 = 0.71) and EUROHIS-QOL8 ( = 0.39; p < 0.0001; R2 = 0.68) in the patient, respectively. Variables related to the caregiver were not associated with changes in the patient´s health-related QoL (PDQ-39 [39-item Parkinson’s disease Questionnaire]) or autonomy for activities of daily-living (ADLS [Schwab & England Activities of Daily Living Scale]). Conclusion: The change in the caregiver’s mood and global QoL was associated with the change in the patient’s mood and global QoL, respectively, independently of other variables of the disease influencing both patient´s aspects. Based on this finding, it could be of great importance to detect depression in the principal caregiver of a patient and act on it as earlier as possible.