ABSTRACT
Studies suggest that Parkinson's disease (PD) is associated with a particular group of personality characteristics. With relative uniformity, PD patients are described as industrious, rigidly moral, stoic, serious, and nonimpulsive. In this controlled study, we used a recently developed personality questionnaire, Cloningers's Tridimensional Personality Questionnaire, to test the hypothesis that these personality traits are behavioural manifestations of damaged dopaminergic pleasure and reward systems. We found significantly less (p < 0.01) of a group of traits called "novelty seeking" in PD patients compared with matched medical controls. Patients with low novelty seeking are described as being reflective, rigid, stoic, slow-tempered, frugal, orderly, and persistent, characteristics similar to those in the clinical description of PD patients. We review evidence supporting the claim that novelty seeking is dopamine-dependent, and suggest that damage to the mesolimbic dopaminergic system causes the described personality profile of PD patients.
Subject(s)
Dopamine/metabolism , Parkinson Disease/psychology , Personality , Avoidance Learning , Exploratory Behavior , Humans , Limbic System/metabolism , Middle Aged , Parkinson Disease/metabolism , Personality Tests , RewardABSTRACT
Clinicians have long observed an anecdotal association of Parkinson's disease with stoic, industrious, and inflexible personality traits, both premorbidly and after the onset of motor symptoms. In this study, using the Tridimensional Personality Questionnaire, we found significantly less novelty-seeking behavior (behavior thought to be dopamine-dependent) in Parkinson's disease patients than in matched controls, but no differences between groups in behaviors thought to be dependent on serotonin and norepinephrine. We discuss the literature and propose a mechanism that may explain the relationship between brain dopaminergic systems and personality in Parkinson's disease.
