Neuropsychological and emotional correlates of personality traits in Parkinson's disease.

Parkinson's disease (PD) is, apart from the well-known motor symptoms, also characterized by neuropsychological and emotional disturbances. However, patients also often present with a personality profile of low Novelty Seeking and high Harm Avoidance. This profile can be identified as the disease emerges, which raises the question whether these traits correlate with more fundamental neuropsychological and emotional disturbances. This study determined the neuropsychological and emotional correlates of Novelty Seeking, Harm Avoidance and two other personality traits that are often considered in PD, i.e. Reward Dependence and Persistence. Forty-three patients and 25 healthy participants were assessed with the Temperament and Character Inventory, a symptoms of depression questionnaire and neuropsychological tests. PD patients showed a higher Harm Avoidance than healthy participants, which was predicted by symptoms of depression. Groups did not differ regarding Novelty Seeking, Reward Dependence and Persistence. While cognitive flexibility was a predictor of Reward Dependence, Persistence was predicted by divergent thinking and inhibition. Novelty Seeking was not predicted by cognition or emotion. In conclusion, cognition and emotion are selectively related to personality traits in PD. Whereas Harm Avoidance covaries with emotional symptoms, Persistence and Reward Dependence are related to cognition. Alterations in personality, cognition and emotion in PD are thus not independent from each other.