Genetics Excuse Some Heroin Dropouts

B O S T O N, Sept. 14 -- Heroin users with a genetic variation that prevents them from kicking the habit may need to try alternative treatments — even including taking small sustained doses of the drug, researchers report today.

The scientists, led by Dr. Ernest Noble, a psychiatrist at Neuropsychiatric Institute and Hospital at the University of California Los Angeles, report their results in the forthcoming issue of Neuropsychiatric Genetics.

In the report, they say they have linked a previously identified “pleasure-seeking gene” to heroin users unable to get through addiction treatment successfully.

Researchers followed 95 heroin patients who entered a rehab program using methadone, a drug treatment that helps some, but not all, heroin addicts kick the habit. Of the patients in this study, 54 successfully completed treatment, but 22 dropped out and 19 fared poorly.

Rehab Dropouts Had Gene The researchers found the drug addicts who failed this program were four times more likely to have the pleasure-seeking gene. Specifically, of the patients studied, 22 percent of those who failed the program and 42 percent of those who had a poor outcome had the genetic variation, compared to only 9 percent of the patients who successfully completed treatment.

And before entering the program, those with the gene had used, on average, twice as much heroin as those without it.

“Heroin users who have this genetic variation may suffer from a more virulent form of the addiction that is less amenable to the standard course of treatment,” says Noble, a former director of the National Institute on Alcohol Abuse and Alcoholism. “I don’t think these patients can get off drugs — if they don’t use heroin, they’ll use other things.”

The gene is present in about 30 percent of the population, and may predict a tendency toward addiction in general. “If you have a certain form of this gene, you are more susceptible to substance abuse problems,” says Noble.