Premorbid Personality and the Risk of Parkinson’s Disease

Objective: To evaluate the association of Parkinson's disease (PD) with premorbid personality indicators in early adult life.

Background PD has been shown to be associated with premorbid personality characteristics such as inflexibility, anti-social behavior and caution. Most studies of parkinsonian premorbid personality relied on subjective reports of personality in early life, which may be subject to recall bias.

Design/Methods: In-person assessments of 89 cases with PD and 99 controls were completed at an academic medical center. Risk-taking activities and behaviors, routinization, smoking and alcohol consumption from ages 20-35 were used as indicators of early-adult life personality. Logistic regression analysis was employed to examine associations between early-adult personality indicators and risk for PD controlling for age, sex and education.

Results: The risk for PD was associated with taking or wanting to take fewer activity risks as a young adult in the total sample (OR=0.78 (95% CI 0.63-0.97)) and among women (OR=0.69 (95% CI 0.50-0.95)). The risk for PD among women also was associated with greater preference for a routine lifestyle as a young adult (OR=1.63 (95% CI 1.05-2.53)). When other personality indicators were included in the model, the association between risk-taking as a young adult and PD remained unchanged.

Conclusions: PD was associated with taking or wanting to take more activity risks and a greater desire for routinization during young adulthood, consistent with the presence of a distinct premorbid personality. These findings suggest that personality characteristics in early life may be useful in the identification of individuals at higher risk for PD and provide insight into the pre-clinical period of the disease.