WEDNESDAY, March 4 (HealthDay News) -- Genetic variants that increase cocaine addicts' risk of paranoia have been identified by U.S. researchers.

In their study of almost 4,000 people of African and European descent, the Yale University and Boston University School of Medicine team examined an area of the genome previously shown to be associated with cocaine dependence and cocaine-induced paranoia.

The researchers conducted a genetic analysis of 11 variants of the a-endomannosidase (MANEA) gene, which metabolizes complex carbohydrates. They found that nine of the variants were linked to cocaine-induced paranoia among African-Americans, and six variants were identified among Americans of European descent.

Variants in this area of the genome were also associated with cocaine dependence.

The study was published in the March issue of the Archives of General Psychiatry.

"We feel that these findings are of great interest because of the novelty of the physiological pathway involved," Dr. Joel Gelernter, a professor of psychiatry, genetics and neurobiology, and director of the Division of Human Genetics in Psychiatry at Yale University School of Medicine, said in a Yale news release.

"This is one of the great advantages of taking a genome-wide approach to discovery of risk variants for complex traits like cocaine-induced paranoia -- you can learn about mechanisms that you would probably have never considered beforehand. This will open a new line of inquiry into the physiology of cocaine-induced paranoia, and possibly into symptoms of paranoia more generally," Gelernter said.

Related MedlinePlus Pages:

• Cocaine
• Genes and Gene Therapy