Caucasians may be more likely to need substance abuse help for cocaine addiction than other individuals, as a new study has found that one in five carry a genetic variant that sharply increases the risk of addiction.

Researchers from Ohio State University found that 19 percent of whites have a set of genetic mutations in their DNA that alter the brain's response to specific chemical signals. This alteration in genes puts individuals at three times the risk of severe cocaine abuse, which may lead to addiction or overdose.

The mutation disrupts the way the brain processes the neurotransmitter dopamine. Previous studies have shown that dopamine plays a critical role in cocaine addiction. The drug works by blocking receptor cells in the brain from absorbing the neurotransmitter. This leaves free dopamine in the brain, which creates a sense of euphoria.

Researchers said that their findings may lead to the development of improved medications for treating cocaine addiction. When these are combined with drug rehab, individuals may have a much better chance of kicking their addiction.