Predictors of Quality of Life in Parkinson's Disease: The Role of Mental Health and Internalized Stigma

Abstract

Background: Parkinson's disease (PD) is a progressive neurodegenerative disorder that negatively affects the well-being of both patients and their caregivers. Therefore, the aim of the present study was to identify factors associated with quality of life (QoL) in patients with Parkinson's disease (PPD) and caregiver burden in their primary caregivers (PCG).

Methods: We conducted a cross-sectional study at a tertiary neurological center in Mexico. Assessments included the Parkinson's Disease Questionnaire (PDQ-39); motor severity with the Movement Disorder Society–Unified Parkinson's Disease Rating Scale Part III (MDS-UPDRS III); cognition with the Montreal Cognitive Assessment (MoCA); depressive and anxiety symptoms with the Patient Health Questionnaire-9 (PHQ-9) and the Generalized Anxiety Disorder-7 (GAD-7); and internalized stigma with the King Internalized Stigma Scale (ISS). Caregiver burden was measured with the Zarit Burden Interview (ZBI).

Results: We included 48 PPD (58.3% male) and 38 PCG (55.3% female). Mean disease duration was 7.3 years [standard deviations (SD) = 4.6; range 1–26 years]. Among PPD, 97.9% were on dopaminergic replacement therapy and 43.8% reported comorbidities. Anxiety severity differed between groups (χ² = 11.7, p = 0.008). No between-group differences were observed in internalized stigma (ISS total score and subdomains). A significant discrepancy emerged regarding assistance with activities of daily living (ADLs), reported by 63.2% of PCG versus 20.8% of PPD (p < 0.001). Linear regression models showed that poorer QoL in PPD was associated with depressive and anxiety symptoms and motor severity (MDS-UPDRS III) (R² = 0.47). Caregiver burden in PCG was associated with depressive symptoms and perceived discrimination (ISS subdomain) (R² = 0.53).

Conclusions: Comprehensive PD management, beyond motor control, should incorporate the evaluation and support of mental health, alongside stigma-reduction strategies, to enhance the well-being of both PPD and their PCG.