Researchers at the UC San Diego School of Medicine reported Tuesday that they have identified 34 neural factors that predict adolescent alcohol consumption, which could identify at-risk youth before they start drinking heavily.
According to the study, published in the American Journal of Psychiatry, the list was based on algorithms analyzing data from neuropsychological testing and neuroimaging studies.
“Underage alcohol consumption is a significant problem in this country,” said psychiatry professor and senior study author Susan Tapert.
“Being able to identify at-risk children before they begin drinking heavily has immense clinical and public health implications,” Tapert said. “Our findings provide evidence that it’s possible to predict which adolescents are most likely to begin drinking heavily by age 18.”
A mix of social, psychological and biological mechanisms are believed to contribute to alcohol use during adolescence, the researchers said. Demographic risk factors include being male, having higher levels of psychological problems and associating positive outcomes with alcohol — like having fun while drinking.
In the study, 137 subjects between the ages of 12 and 14 — of whom 97 percent had never tried alcohol — underwent a battery of neuropsychological tests and functional magnetic resonance imaging of their brains. They were then assessed annually.
By age 18, just over half of the youths were found to be moderate to heavy users of alcohol, based on drinking frequency and quantity, and the rest continued to abstain.
The scientists employed a machine-learning algorithm known as “random forests” to develop a predictive model. Random forest classification is capable of accommodating large sets of variables while using smaller study samples to produce consistently strong predictions.
Among the findings, 12- to 14-year-olds were more likely to begin drinking by age 18 if they:
— were male and/or came from a higher socioeconomic background;
— reported dating, displayed behaviors like lying or cheating, and believed alcohol would benefit them in social settings;
— performed poorly on executive function tests; and
— had neuroimaging results that indicated thinner cortices — the outer layer of neural tissue covering the brain.
The authors said neuroimaging significantly increased predictive accuracy, compared to using demographics alone.
They said the study did not extend to the early use of marijuana because only 15 percent of the sample reported eventually using marijuana more than 30 times, but the authors said it was possible that the reported risk factors for alcohol use also apply to cannabis and other illicit substances.
They said further and larger studies are necessary.
“The value of this particular study is that it provides a documented path for other researchers to follow, to replicate and expand upon our findings,” Tapert said. “Ultimately, of course, the goal is to have a final, validated model that physicians and others can use to predict adolescent alcohol use and prevent it.”
Researchers from the Medical University of South Carolina, Stanford University, the VA San Diego Healthcare System and the Laureate Institute for Brain Research in Tulsa, Oklahoma, also took part in the study.
Funding was provided by, in part, the National Institute on Alcohol Abuse and Alcoholism and the National Institute on Drug Abuse.
–City News Service
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