Personality traits and the risk for Parkinson disease: a prospective study.

In this study, we explored the association between the personality traits, neuroticism and introversion, and risk of Parkinson disease (PD). A population-based cohort study was conducted using questionnaire data from the Swedish Twin Registry for twins born 1926-1958 (n > 29,000). Personality traits were assessed in 1973 by a short form of Eysenck's Personality Inventory.