TURKU, FINLAND. For nearly a century it has been suggested that people who develop Parkinson's disease tend to be morally rigid, punctual, serious, compulsive, industrious, introverted, and quiet – in other words, not exactly "laid-back". More recent research has found a correlation between a lack of novelty- seeking behaviour and Parkinson's disease in patients taking l-dopa. People who score low on novelty seeking tend to be rigid, loyal, stoic, frugal, orderly, and persistent.
Finnish researchers now report the results of an experiment designed to test the personality/Parkinson's association. The trial involved 61 un-medicated Parkinson's disease patients and 45 healthy controls. All participants filled out personality questionnaires and 47 of the patients also underwent a PET scan to evaluate dopaminergic activity in the brain. The researchers found no correlation between the incidence of Parkinson's disease and novelty seeking. They speculate that the lower novelty seeking found in previous studies were caused by the patients' medication (l-dopa). However, they did find a clear correlation between harm-avoidance and Parkinson's. People with the disease were more likely to describe themselves as fearful, pessimistic, shy, and easily fatigued (high harm-avoidance score) rather than as optimistic, outgoing risk takers. The researchers also found a clear association between l-dopa uptake in the brain (right caudate nucleus) and a high harm-avoidance score.
Kaasinen, Valtteri, et al. Personality traits and brain dopaminergic function in Parkinson's disease. Proceedings of the National Academy of Sciences, Vol. 98, November 6, 2001, pp. 13272-77