Study helps predict which teens may abuse alcohol later in life

Researchers at the Medical University of South Carolina think if health care providers and parents knew that certain factors influence which 12 year olds grow up to abuse alcohol, they could intervene earlier to target these teens.   

At least that’s the goal of MUSC researcher Lindsay Squeglia, Ph.D., who is the lead author of a study published in The American Journal of Psychiatry.

The study identified 34 factors that could be useful in predicting adolescent alcohol consumption. The list was compiled based on demographic, neuropsychological and neuroimaging factors and computed using complex algorithms.

“Alcohol and marijuana do affect how the brain develops, but this study suggests certain children have vulnerabilities that make them more susceptible even before that exposure affects their brain.”

Teenage drinking is common in the United States, with approximately 66 percent of 18-year-olds reporting alcohol use. That translates to poor outcomes for these youth, including higher rates of violence, missing school, drunk driving, suicide and risky sexual behavior. It accounts for more than 5,000 deaths each year.

“The research has helped destigmatize this as a true disorder. We don’t have to deal with these severe alcoholic populations as adults if we intervene earlier.”

Squeglia, who is an assistant professor in MUSC’s Department of Psychiatry and Behavioral Sciences, collaborated with researchers at the University of California San Diego School of Medicine. She specializes in understanding the effects of alcohol and marijuana use on adolescent brain development, focusing on the use of structural and functional neuroimaging and neuropsychological testing.

Her other research goal: creating effective treatment options for substance-using youth.

“If we can identify kids who are more likely  to use substances earlier, and we can intervene earlier, we could have a greater impact on outcomes. Some of the previous studies have shown that kids who start using alcohol by age 15 are four times more likely to develop an alcohol-use disorder by adulthood. So it’s really important to identify these kids early.”

Squeglia became involved with this study when she was in San Diego completing her Ph.D. and postdoctoral work in clinical psychology. Researchers chose a high functioning, affluent group of children in the La Jolla area in San Diego, California, who had no mental health issues. There were 137 participants, ages 12 to 14, who had never had alcohol. They underwent neuropsychological testing and structural and functional magnetic resonance imaging and then were followed annually.  By age 18, 51 percent had initiated moderate to heavy alcohol use.

She said this was the first study to compare scans accessed over a such a long time span, including a period before the teenagers had been exposed to alcohol. “There are interesting factors that exist in the brain before any of these kids ever take a sip of alcohol." 

The model the researchers developed contained 34 predictors contributing to alcohol use by age 18, including several demographic and behavioral factors, such as being male; having a higher socioeconomic status; early dating; more externalizing behaviors, such as lying; and positive alcohol expectancies.

Other predictors included:

• Performing poorly on executive function tests,
• Neuroimages showing thinner cortices, which is the outer layer of neural tissue covering the brain,
• And less brain activation in in key brain regions involved in executive functioning and decision making.

“When we see these risk factors even in high-functioning kids, we know there could be even more problems with children who have mental health issues that could make them more susceptible to abusing substances.”

It’s a strength of this study that high-functioning kids were used, she said.

“People will say, ‘It was their choice to start using, and they just kept using.’ There are a lot of studies that show that alcohol and other substances affect people differently. Some find it much more rewarding than others because their brain is set up in a way to be more vulnerable to it. This helps show that alcoholism is a brain disease. It’s not a moral disease. There are physiological differences that make some people much more susceptible.”

The study used a random forest model, a machine learning tool that is one of the most robust predictive techniques, helpful for looking at issues such complex issues as substance abuse, she said.

“Why people start using drugs and alcohol is multi-faceted. We can look at all these reasons together in a more complex, comprehensive way than we were able to before. My favorite part about this study is that we’re publishing the scripts we used for the analyses in hopes that other groups will replicate the findings.”

More research is needed. Squeglia said she’s excited that MUSC will be part of a long-term project, the National Institutes of Health’s Adolescent Brain Cognitive Development study, that will recruit 11,500 healthy children, ages 9 to 10, across the nation and follow them into early adulthood. One of the aims is to determine how exposure to substances, such as alcohol and marijuana, affects development.

For now, doctors are far from routinely putting teens in brain scanners, but studies such as these will get parents and clinicians to rethink treatment, she said.

“I’m also interested not only understanding predictors of use and how alcohol affects the brain, but also treatment. We know alcohol and marijuana use isn’t great for the developing brain so what can we do to intervene earlier? What treatments are going to be most effective? What works for adults isn’t necessarily true for teens, whose brains still are developing until age 25.”

Squeglia, who gives community talks, said educational programs such as MUSC’s Just Say Know can be targeted to groups that are more at risk. There needs to be better dissemination to the public and more programs to strengthen executive functioning in at-risk youth.

The reward system of the adolescent brain develops before the cognitive control system. “A lot of people use the analogy of the adolescent brain having a lot of gas pedal and not a lot of brakes. So the frontal lobe isn’t fully developed, but their emotional and reward centers are, so they find things really, really rewarding, but they might not have the full ability to withhold getting that reward.”

Research can explore how to dampen the reward response to substance use and find treatments that bolster frontal lobe capacity to inhibit impulsivity, she said.

In the meantime, adults need to open up informed conversations with teens. Adolescents whose parents talk to them about alcohol use are 42 percent less likely to drink than teens whose parents don’t talk to them. “My goal is to reduce the number of youth drinking, to delay the age on onset and reduce the amount they are drinking.”

Squeglia, who loves studying teens, said she believes teens want good information to make better decisions. “I want to tell them, ‘Here’s information about your brain that’s still developing until you’re age 25. This is such an important time in your life. You want the best brain you can have. Here’s how your brain develops and how substance abuse affects it. You do what you need to do with that information.'”

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For more information about MUSC’s Just Say Know program, a science-based alcohol and drug prevention program designed for 8-12 grade students by MUSC, call 843-792-9531 or email Sylvia Rivers. If you’re interested in a community talk, email Lindsay Squeglia. 

For tips on how to educate teens about alcohol's impact on developing brains, check out these tips from Dr. Squeglia.