Parkinson’s Disease (PD) and Family Functioning: A Quantitative Triadic Analysis of Individuals with PD and Their Family Members

Parkinson’s Disease (PD) is a progressive neurodegenerative disorder that not only alters physical and cognitive functioning but also disrupts family roles and relationships. While most existing research has emphasized individual or dyadic perspectives, little is known about how PD shapes dynamics across entire family systems. Guided by the Bio-Psycho-Social-Spiritual model of Medical Family Therapy (MedFT), this study examined family functioning in triads consisting of a person with PD (PT), a primary caregiver (PC), and a secondary caregiver (SC). Using a cross-sectional survey design, 114 participants (38 families) completed measures of perceived disease severity (PDCS), family functioning (MFAD), pre-death grief (PG-12), and spirituality or religiosity (CPSR). Results indicated significant role-based differences in perceptions of family functioning. Patients reported the highest levels of (dys)function, followed by SCs, while PCs reported the lowest levels. A triadic Actor-Partner Interdependence Model revealed no significant actor effects but identified one significant partner effect: SCs’ perceptions of disease severity predicted PCs’ perceptions of family (dys)function. Regression analyses further showed that pre-death grief significantly predicted higher perceptions of family (dys)function among patients, but not among caregivers. Contrary to expectations, spirituality/religiosity was not significantly associated with pre-death grief for any role. These findings should be viewed as an initial step toward understanding the relational complexities of PD within families. Our hope is that this work contributes to ongoing conversations about policy and access to family-based treatment, particularly in systems where such care is not yet routinely available.