Genetics play a role in addiction, but there are other causative agents. Norman G. Hoffmann, PhD, adjunct professor of psychology at Western Carolina University, likens an individual’s genetic disposition to lactose tolerance. In Northern Europe, where cattle have been domesticated for hundreds of years, the vast majority of people have no difficulty metabolizing lactose. But in countries where cattle domestication occurred much later, far fewer people tolerate lactose.
For lactose tolerance, one gene is responsible. But in addictions, the role of genetics is far more complicated. More genes are involved.
Genetic predisposition is certainly a factor in severe substance use disorders, i.e., dependence, but heritability is not the only factor, Hoffmann told attendees at the NCAD conference in Anaheim, Calif. on Sept. 22. Also critical to addiction are age and epigenetics, that is, the effect of environmental factors on gene expression.
Adolescents most at risk
Take age. “The risk for developing dependence is greatest when use begins at a young age,” Hoffmann said. “The earlier the introduction of substances, the greater the probability of problems.” And most addictions begin with smoking.
“Nicotine is one of the most powerful addictive substances,” Hoffmann states. It is a true gateway drug,. The earlier a youth starts smoking, the greater the risk. Nicotine affects young smokers by predisposing them to response to other substances, especially cocaine. Not only that, adolescents become addicted to nicotine very rapidly—in a matter of weeks or days.
School systems attempt to address the issue, often with programs such as the D.A.R.E. program, refusal skills training, and drug testing of students in extracurricular activities. But those programs don’t work, says Hoffmann, who says the ones that work are more individual and holistic. They involve parents and community, recognize genetic diversity, monitor progress and effectiveness over time, and coordinate with structured treatment programs.
Start programs early, he advises, and use programs that are age-appropriate. In grade school, information is important, but by middle school, it’s time to focus on current behavior and how to make informed decisions. For high schoolers, how to make informed decisions is still important, but programs should also include secondary prevention to identify those getting into trouble.
Nature vs. nurture
Epigenetics brings up ‘nature vs. nurture’ as a causative agent. It is neither, he says. Rather, there is an interplay between the two. “The interplay between your genetics and your experiences have a great bearing on your condition, how you react to it, and what types of treatment are most effective,” he said.
Above all, Hoffmann reiterates the importance of recognizing individual differences: “We’re all wired a little differently.”