TUESDAY, Dec. 28 (HealthDay News) -- A new study suggests that many white people carry a genetic trait that boosts the risk they'll develop an extreme and possibly deadly cocaine habit.

The trait appears to triple the odds of becoming susceptible to severe cocaine abuse that leads to death from an overdose, compared to non-carriers.

Researchers found signs of the genetic variation in more than 40 percent of brain samples taken from whites who abused cocaine. It was in just 19 percent of whites who didn't take drugs.

Overall, the genetic variant showed up in one in five samples from whites in the control group (and one in two to three samples in the cocaine overdose group), compared to one in eight African Americans, in whom the variant is less common.

The variations affect a neurotransmitter called dopamine that plays a role in helping the brain to feel euphoria when people take cocaine.

"We now have both good biological rationale and clinical association showing that this has an impact on the way cocaine abuse might progress or might be initiated," said study senior author Wolfgang Sadee, professor of pharmacology and director of the Program in Pharmacogenomics at Ohio State University, in a university statement.

"We have found a frequent variant in one of the key candidate genes that can affect cocaine abuse, but more importantly, it also opens the avenue to explore how this variant affects response to therapies for a variety of psychiatric disorders that involve dopamine."

More research is needed before the gene variants could be considered a marker for cocaine sensitivity, the researchers said.

The study is published online in the journal Neuropsychopharmacology.

More information

Learn more about cocaine from the U.S. National Library of Medicine.