3 September 1999

The trip inside your head

by Kate Melville

A new mechanism appears to explain for the different levels of elation people experience when taking a stimulant drugs.

The research conducted at Brookhaven National Laboratory in Upton, New York, and at the State University of New York at Stony Brook was funded by the American National Institute on Drug Abuse (NIDA) and U.S. Department of Energy.

It found that people who have lower levels of dopamine D2 receptors in their brains are more inclined to like the effects of methylphenidate, a mild stimulant, than people who have higher levels of these receptors and who were found to dislike the drug's effects. NIDA Director Dr. Alan I. Leshner says, "This finding supports the theory that brain chemistry may predispose some people to becoming drug abusers. Understanding these biological issues will help us learn why some people are particularly vulnerable to abusing drugs and provides new potential targets for both prevention and treatment efforts."

The study used a brain imaging technique called Positron Emission Tomography to measure dopamine D2 receptor levels in the brains of 23 men who were not drug abusers. The men were given methylphenidate and then asked to describe its effects. Twelve described the drug as made them happy or improving their mood.

Nine described the drug as disagreeable, saying that it made them annoyed or distrustful.

Two described the drug as having a neutral effect.

The results showed those who described methylphenidate's effects as pleasant had lower numbers of D2 receptors than did those who described the drug's effects as disagreeable.