Parkinson’s disease (PD) has been associated with risk aversion and less addictive behaviour. Little is known about the prodromal stages. Personality and its relationship with addictive behaviours may provide clues to mechanisms underlying PD and addiction.Methods
941 early PD subjects, 128 rapid eye movement sleep behaviour disorder (RBD) subjects and 292 control subjects were assessed (motor and non-motor).Results
Patients with early PD were more neurotic, less extraverted and less open than controls. RBD subjects showed the same pattern of being more neurotic (p<0.001), less extraverted (p=0.03) and less open (p<0.001). PD patients smoked less (p=0.02) and drunk less alcohol (p=0.03) than controls. Being more extraverted, more open and less neurotic predicted higher alcohol use (all p values<0.001), while being more extravert (p=0.007) and less agreeable (p<0.001) was associated with smoking more. PD remained inversely associated with smoking even after adjustment for personality (odds ratio 0.73, 95% CI 0.55–0.97, p=0.03).Conclusions
Similar personality patterns are seen in PD and RBD compared to a control population. Personality characteristics were associated with addictive behaviours, suggestive of a common link, but the lower rates of addictive behaviours before and after the onset of PD persisted after accounting for personality.