Building on prior studies with rodents, the researchers examined differences in the neural structure of human risk-takers by analyzing personality-trait questionnaires completed by 34 healthy adults -- 18 men and 16 women, with an average age of about 24.
The participants answered questions about their novelty-seeking tendencies, spontaneity, decision-making speed, and rule-breaking inclinations. The researchers then compared the responses to brain scans of the same participants.
The results: Those who displayed risk-taking traits possessed a smaller number of dopamine auto-receptors in their brains, giving them a relatively weakened ability to control and inhibit dopamine release.
Dr. Adam Bisaga, an addiction psychiatrist at the New York State Psychiatric Institute, agreed that the findings could help lead to improved addiction treatment.
"The importance of this research is that, hopefully, in the future, we'll be able to treat patients better, because we can do some genotyping and target treatment better depending on a patient's genetic make-up," Bisaga said. "Probably, dopamine receptor variability is not going to explain all the differences in behavior. It's a little more complicated than that. But this work now gives us at least some biological basis for understanding temperament and other personality characteristics."
For more on drug abuse and addiction, visit the U.S. National Institute on Drug Abuse.
SOURCES: David H. Zald, Ph.D., associate professor, department of psychology, Vanderbilt University, Nashville, Tenn.; Adam Bisaga, M.D., associate professor of clinical psychiatry, the College of Physicians and Surgeons of Columbia University, and research scientist, New York State Psychiatric In
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