Marijuana dependence influenced by genes, childhood sexual abuse

http://www.eurekalert.org/pub_releases/2015-11/wuis-mdi111015.php

Public Release: 16-Nov-2015
Marijuana dependence influenced by genes, childhood sexual abuse
Genetic differences may protect some who experienced childhood trauma from later marijuana dependence, study finds
Washington University in St. Louis

Genetic variation within the endocannabinoid system may explain why some survivors of childhood adversity go on to become dependent on marijuana, while others are able to use marijuana without problems, suggests new research from Washington University in St. Louis.

"We have long known that childhood adversity, and in particular sexual abuse, is associated with the development of cannabis dependence.

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"As we expected, childhood sexual abuse was overall associated with individuals reporting a greater number of cannabis dependence symptoms," Carey said. "But what was particularly intriguing is that this association was only seen among people with two copies of the more common G allele. People with at least one copy of the less common A allele did not show this pattern, so these data suggest that the A allele may provide some form of resiliency to the development of dependence.

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"It's important to mention that these findings are unlikely to be informative at an individual level," Carey said. "We won't see a genetic test for cannabis dependence anytime soon, if ever, but it's a start."