Meaning in life and Parkinson's disease: Evidence from a 17-year study across 14 countries

Meaning in life is associated consistently with a reduced risk of incident Alzheimer's disease and related dementias. It also changes across the disease continuum. Less work has examined the association between meaning in life and Parkinson's disease and the natural history of meaning with onset of Parkinson's disease has yet to be evaluated. This study examines the prospective association between meaning in life and incident Parkinson's disease and evaluates changes in meaning in life prior and after onset of Parkinson's disease.

This prospective cohort study used assessments of meaning in life and incident Parkinson's disease from 2004 to 2022 in the Survey of Health, Ageing and Retirement in Europe. Meaning in life was measured with a single-item measure from the Control, Autonomy, Self-realization and Pleasure scale. Parkinson's disease was self/proxy-reported doctor diagnosis up to 2022.

Accounting for age, sex, and education, greater meaning in life was associated with lower risk of developing incident Parkinson's disease over up to 17 years follow-up. This association was accounted for behavioral, clinical, and psychological factors. Accounting for demographic differences and normative changes that occur in meaning, meaning in life did not decline significantly before the onset of Parkinson's disease but showed a significant and accelerated decline following disease onset.

Behavioral, clinical, and psychological risk factors accounted for the association between meaning in life and risk of Parkinson's disease. Meaning in life levels remained stable before Parkinson's disease's onset but declined significantly afterward, paralleling the worsening of psychological outcomes in Parkinson's disease.