Exploration of Parkinson's Disease Symptomatology Subtypes From the Caregiver Perspective: Implications for Caregiver Burden, Depression, and Anxiety

Background: While research has demonstrated associations between Parkinson's disease (PD) severity and caregiver burden and emotional functioning, less is known about the associations between specific PD symptom patterns and caregiver functioning. Objective: The purpose of the current study was to explore symptomatology subtypes in PD from the caregiver perspective in the U.S. and Mexico and to determine whether caregiver burden, depression, or anxiety differed by PD symptomatology subtype. Methods: Two hundred fifty-three caregivers (M age = 59.9) completed Parts I and II of the Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS), the Zarit Burden Interview, Patient Health Questionnaire-9, and Generalized Anxiety Disorder-7 scales. Results: Cluster analysis using domains from the MDS-UPDRS revealed 5 symptomatology subtypes: pain/motor predominant, low symptoms, severe diffuse symptoms, moderate restricted symptoms with speech/oral predominant, and mood predominant. Caregiver burden was greatest for caregivers of individuals in the severe diffuse symptom and moderate restricted symptoms with speech/oral predominant clusters. High caregiver depression and caregiver anxiety were observed in all clusters other than the low symptoms cluster. There were no site by cluster interactions, suggesting that symptom patterns contribute to caregiver functioning in similar ways in the U.S. and Mexico. Conclusions: This data-driven analysis revealed 5 symptomatology subtypes of PD from caregivers' perspectives and highlighted the need for treatments and interventions based on predominant PD symptom expression. Importance of caregiver support across various symptomatology expressions, and particularly on specialist treatment for predominant speech/oral difficulties was recommended.