Substance abuse during the adolescent years can have significant lifelong consequences on the developing brain. "Both animal models and observational studies in humans suggest that binge drinking during adolescence alters normal developmental processes in a way that negatively impacts learning and social adjustment into adulthood," says study researcher Robert J. Thoma, PhD, a psychiatrist at the Center for Neuropsychological Services of the University of New Mexico, Albuquerque, in an email.
"On one hand, the adolescents in our study were functioning largely within the normal range on cognitive tests, [but] it is likely that they are under-performing on many of these tasks relative to their ability before initiation of binge drinking," he says.
"Consistent under-performance in school could shift an adolescent’s trajectory of educational attainment, thereby affecting subsequent job placement and socioeconomic status," he says.
Testing Teen Drinkers
The new study involved 48 teens aged 12 to 18. Of these, 19 had diagnosed substance abuse disorders, 14 had a family history of substance abuse (but not a personal history), and 15 had no personal or family history of substance abuse.
All of the study participants completed a battery of tests assessing their memory, attention, executive function, reasoning with words, how quickly they process new information (processing speed), and their ability to visually perceive the space between objects.
The average number of drinks per drinking day reported by teen binge drinkers was 13. The more alcohol the teens drank, the greater the deficits in their attention and executive function, the study shows. In addition, smoking marijuana had an independent effect on memory.
Substance Abuse Prevention
The new findings underscore the need for enhanced substance abuse prevention and treatment efforts targeted toward teens. "Education programs, controlling advertising aimed at teens, and limiting the accessibility of alcohol for this population are all viable methods of reducing problem drinking in adolescents," Thomas says. "For parents worried about their child's drinking, I would recommend work with school counselors, nurses, pediatricians, or any accessible health care provider to find a treatment program that both parents and child feel comfortable with."
"This study should be of concern to all of us," says Henry Wechsler, PhD, a lecturer at Harvard School of Public Health in Boston, in an email. "It suggests that adolescent drinking may have serious long-term consequences."
Almost 30% of high school seniors and 40% of college students are binge drinkers, he says. Wechsler was the principal study investigator for the Harvard School of Public Health College Alcohol Study.
"We cannot shrug off youthful alcohol use as just a passing stage or a 'rite of passage,' nor can we accept the suggestion of some that we drop the minimum legal drinking age to 18, and make alcohol more available to high school and college students," he says.
"The developing adolescent brain is more vulnerable to alcohol and drug abuse than the fully developed adult brain," says Tom Hedrick, a founding member of Partnership at Drugfree.org. "The area that is still developing during adolescence -- the frontal lobe-- is the part of the brain that makes judgment decisions, weighs risks vs. benefit, and can put a hold on impulsive behavior."
"This study is another example that shows helping kids with a forceful message about avoiding drugs and alcohol is the right thing to do," he says. The Partnership at Drugfree.org is a nonprofit group based in New York City that helps parents prevent, intervene in, and find treatment for drug and alcohol problems in their children.