Objective: Determine current personality characteristics of PD cases and assess their correlation with more objective indicators of early-adult life personality in cases and controls.

Background Parkinson's disease (PD) patients have been reported as having an introverted, rigid and harm-avoidant personality. Although these characteristics have been attributed to a pre-morbid personality, previous studies have relied on subjective reports of patients' previous personalities that may have been biased by current symptoms.

Design/Methods: We conducted a case-control study of 89 PD cases and 99 controls. In-person assessments evaluated current personality characteristics using standard instruments (NEO-FFI; TCI). Risky activities and behaviors as well as preference for a routine lifestyle between ages 20-35 were used as indicators of early-adult personality. Pearson correlations were obtained for associations of early-adult risky activities and routinization with current personality characteristics, partialling out the effects of age, sex and education.

Results: Current levels of neuroticism (OR=1.05 (95% CI 1.00-1.11)) and harm-avoidance (OR=1.07 (95% CI 1.00-1.15)) were higher in cases compared with controls, adjusted for age, sex and education. Correlations between early-adult indicators and current personality characteristics were consistent among both cases and controls for associations of early-adult life routinization with current levels of extraversion (cases: r=-0.33, p=0.01; controls: r=-0.33, p=0.04), harm-avoidance (cases: r=0.47, p=0.0003; controls: r=0.45, p=0.0002), neuroticism (cases: r=0.33, p=0.01; controls: r=0.26, p=0.04), and novelty-seeking (cases: r=-0.33, p=0.015; controls: r=-0.34, p=0.007); taking or wanting to take activity risks as a young adult was significantly correlated with current levels of harm-avoidance (cases: r=-0.47, p=0.0004; controls: r=-0.42, p=0.0006).

Conclusions: Cases with PD had personalities characterized by higher neuroticism and harm-avoidance. Correlation of these characteristics with early-adult personality indicators suggests that personality characteristics of patients with PD are likely to be stable across the adult life course and not a response to developing symptoms of the disease.