Parkinson's patients not likely to be risk-takers

NEW YORK (Reuters Health) - Patients with Parkinson's disease score lower on an impulsive sensation-seeking tests than their counterparts without the disease, investigators report. This may be why Parkinson's disease patients are less likely to smoke and consume fewer caffeinated beverages and alcohol, which may explain "the hypothetical protective effect of cigarette smoking and caffeine consumption on Parkinson's disease."

Parkinson's patients tend to exhibit low sensation-seeking behavior, which may reflect variations in the activity of brain dopamine systems, Dr. A. J. Lees and colleagues note in their report, published in the Journal of Neurology, Neurosurgery and Psychiatry. Parkinson's disease patients also tend to share other traits such as conscientiousness, anhedonia, and low levels of aggression.

To see how sensation seeking affected behaviors and risks in patients with Parkinson's disease, Dr. Lees, from the Reta Lila Weston Institute of Neurological Studies in London, and colleagues compared standardized test results and habits among 106 patients with Parkinson's disease and 106 healthy individuals of the same age.

Compared with controls, Parkinson's disease patients scored significantly lower on the short version of Zuckerman's Sensation Seeking Scale (3.0 versus 3.9), the Geriatric Depression Scale (11.5 versus 6.8) and the Trait Anxiety inventory (42.8 versus 35.7). However, Zuckerman's Sensation Seeking Scale scores were not related to Parkinson's disease duration or severity.

Parkinson's disease was also associated with significantly lower cigarette use, less caffeine intake, and reduced alcohol consumption. In each case, adding Zuckerman's Sensation Seeking Scale score to the logistic regression model reduced the magnitude of the effect of the variable, suggesting that some of the apparent effects of smoking, caffeine and alcohol can be explained by the effect of reduced sensation seeking.

Reduced sensation seeking is the result of individual variations in brain function, which may interaction with environmental factors to lead to increased disease susceptibility, the authors suggest.

SOURCE: Journal of Neurology, Neurosurgery and Psychiatry, March 2006.