Predicting which teens may have substance-use problems in early adulthood is not easy, but a UO researcher has just helped refine the efforts in a way that could be a game-changer for intervention efforts.

Teens at most risk are those who have a weakness in working memory, have trouble controlling impulsive behaviors and progress into heavy use during their early teen years, said Atika Khurana, a professor in the Department of Counseling Psychology and Human Services. Those who briefly experiment with drugs and don't progress into heavier use are at less risk.

Those conclusions emerged from a long-term study of Philadelphia-area adolescents recruited into the study at ages 10-12. Khurana and colleagues at the Annenberg Public Policy Center of the University of Pennsylvania and Children's Hospital of Philadelphia followed 387 of the participants until they reached 18 to 20 years of age.

The study focused on alcohol, marijuana and tobacco use, the most commonly used drugs by adolescents. Researchers assessed and established baselines for the teens' working memory and impulsive tendencies when the study began.

"Substance-use disorders are a major public health concern in this country," Khurana said. "The onset of substance use happens during adolescence. There is a lot of research that links the onset of use to later substance-use disorders. Our study advances the field by showing that just addressing early use is not going to solve the problem."

The study was published online ahead of print Feb. 16 by the journal Addiction.

Working memory refers to the ability to concentrate on a task without being easily distracted. Youth with weak working memory tend to have problems controlling their impulses, such as acting quickly without considering the consequences instead of staying focused on a later goal with a bigger payoff.

"We found that there is some effect that was carried through the early progression in drug use. It is a risk factor," said Khurana, who also is a research scientist in the UO's Prevention Science Institute. "But we also found that the underlying weakness in working memory and impulse control continues to pose a risk for later substance-use disorders."

In previously published work, Khurana's team documented the flip side of the equation — how adolescents with stronger working memory were better equipped to escape progression into heavy use following initial experimentation.

"Unanswered in our earlier work was whether it was specific forms of early use that predict later substance abuse," said Khurana, who was a postdoctoral fellow at the Annenberg Public Policy Center when the long-term study began. "People really hadn't focused on the heterogeneity of drug-use patterns. Some youth can start early and experiment but not progress while others experiment and progress into heavier drug use."

Interventions that strengthen working memory and cognitive processing related to inhibiting impulsive responses need to be developed to help adolescents better navigate drug-related temptations, Khurana said.

Co-author Dan Romer, research director of the Annenberg Public Policy Center, agreed.

“Drug prevention strategy in the schools typically focuses on middle school when early drug use tends to take place and assumes that any drug use at all is a problem,” Romer said. “This study suggests that prevention needs to be more nuanced. The risk depends on whether drug use is likely to progress.”

The National Institutes of Health supported the research through two grants from the National Institute on Drug Abuse.

—By Jim Barlow, University Communications