"The primary finding is important because individuals who are more prone to cue-induced craving may also be more prone to relapse in a high-risk situation," said Hutchison. "In other words, alcoholics with the G allele who are trying to remain abstinent may have more difficulty than alcoholics without the G allele." The secondary finding of greater other-drug use among individuals in the G-allele group is less conclusive, he said.
"The problem is that there are many reasons why people use drugs," he noted. "This genetic marker may influence some of the variables that lead to drug use, but there are many other variables that are not related to this gene. This is part of the reason that there are inconsistencies in the scientific literature."
Nonetheless, both van den Wildenberg and Hutchison noted the importance for treatment options of identifying "risk genes" that predispose certain individuals to alcohol-problems. "Eventually, knowledge about the genetic variables that influence alcohol abuse may be used to help determine which treatment is most appropriate for a given individual," said Hutchison. "For example, an individual who has a gene that confers some vulnerability in a particular system in the brain may benefit most from a treatment that targets this vulnerability."
"In this case," added van den Wildenberg, "patients with a G allele of the mu-opioid receptor gene might benefit from the anti-craving medication naltrexone, which blocks the mu-opioid receptor. Naltrexone has been found to work especially well in alcohol-dependent patients with a G allele, possibly due to a stronger decrease in craving in these individuals."
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3-Jan-2007