Research Suggests Teen Alcohol Use Can Lead to Adult Brain Abnormalities

Second Study Says Binge Drinking Up, Especially Among Women

May 15, 2015 04:06 pm Chris Crawford

Alcohol abuse has touched most patients' lives in one way or another -- whether it is their own abuse or that of a family member or friend. So it's important for family physicians to educate patients, especially adolescents, to make informed decisions about alcohol use.

[Young woman talking with physician taking notes]

Results of two recent studies may offer guidance on how to approach this issue. In the first, researchers sought to explore whether alcohol use in adolescence can lead to long-lasting brain abnormalities in adulthood. The second demonstrated how binge drinking has increased across the United States, led by higher rates of drinking among women.

This Is Your Brain on Booze

Published April 27 in Alcoholism: Clinical & Experimental Research, the first study( found that alcohol consumption in adolescent rats led to long-term structural and functional abnormalities in their hippocampus in adulthood.

According to a news release,( earlier studies by the same research team at Duke University in Durham, N.C., had shown that adolescent animals exposed to alcohol grew into adults that were much less adept at memory tasks than normal animals -- even after no further alcohol exposure.

Story highlights
  • A recent study published in Alcoholism: Clinical & Experimental Research sought to examine how teen alcohol use can lead to brain abnormalities in adulthood.
  • Using rat models, the study found that alcohol consumption by adolescent rats led to long-term structural and functional abnormalities in the hippocampus in adulthood.
  • A second study in the American Journal of Public Health found that binge drinking has increased across the United States, led by higher rates of drinking among women.

For the new study, researchers used small electrical stimuli applied to the hippocampus to measure long-term potentiation (LTP), which is the strengthening of brain synapses as they are used to learn new tasks or conjure memories. "Learning occurs best when this synaptic activity is vigorous enough to build strong signal transmissions between neurons," said the release, so it came as a surprise when the researchers actually found that LTP in these animals was hyperactive compared with that in rats unexposed to alcohol.

"At first blush, you would think the animals would be smarter," said senior author Scott Swartzwelder, Ph.D., professor of psychiatry and behavioral sciences at Duke and senior research career scientist at the Durham Department of Veterans Affairs Medical Center, in the release. "But that's the opposite of what we found. And it actually does make sense, because if you produce too much LTP in one of these circuits, there is a period of time where you can't produce any more. The circuit is saturated, and the animal stops learning.

"For learning to be efficient, your brain needs a delicate balance of excitation and inhibition -- too much in either direction and the circuits do not work optimally."

This finding was accompanied by a structural change in individual nerve cells that suggested they were immature. Researchers suggested the immaturity of the cells could be linked to behavioral immaturity in the adult rats tested and that alcohol could have disrupted the maturation process.

The researchers said additional studies are being planned to focus on longer-term cognitive effects of alcohol on brains and cellular changes.

According to AAFP member Daniel Vinson, M.D., M.S.P.H., professor emeritus in the family and community medicine department at the University of Missouri School of Medicine in Columbia, research in both animals and people has shown that adolescent brains are more susceptible to changes that can lead to addiction, with most addictions in humans beginning between ages 15 and 25.

Family physicians could consider referencing this study, said Vinson, as part of a discussion about alcohol use with adolescent patients, who he described as having a "wonderful sense of invincibility."

"I think every young adolescent (ages 10-14) should be asked about substance use," he said. "Start with a question of, 'Do your friends have a drink of alcohol now and then?' Then, 'What about you? Do you have a drink of alcohol occasionally?'"

If the answer is "no," then the family physician should reinforce that behavior by congratulating the young patient on having made a wise decision, said Vinson. In addition to telling the patient about the study's specific findings, let the patient know that teen drinking can lead to a higher risk of becoming an alcoholic, he said. Recommend the adolescent consider delaying his or her first drink until the brain is fully developed -- well into his or her 20s.

If the adolescent patient admits to drinking alcohol occasionally, Vinson recommends addressing the situation as a chronic problem -- just as the physician would approach a patient with asthma.

"There is no ICD-9 or ICD-10 code for drinking," he said. "But a 15-year-old who is drinking probably needs to be seen back sooner, monitored and encouraged to adopt a healthier lifestyle."

If a family physician knows a patient has a family history of a substance use disorder and thinks the adolescent is aware that, for example, mom or dad has had problems with alcohol, the physician should explain to the patient that such problems are to some extent genetic and the risk of becoming an alcoholic is higher among people with this positive history than those without this history.

"My advice to them would be not to drink," Vinson said, "certainly, not before age 21, and probably not before age 30 or older -- because of that genetic risk."

Binge Drinking Is on the Rise

The second study,( published April 23 in the American Journal of Public Health, tracked trends in alcohol use by Americans 21 and older at the county level from 2002 to 2012.

Among its major findings:

  • heavy drinking has increased more than 17 percent since 2005 and
  • the rate of binge drinking among women increased 17.5 percent between 2005 and 2012 compared to an increase in men of about 5 percent during the same timeframe.

Madison County in Idaho had the lowest rate of binge drinking in 2012, at about 6 percent of its residents, while Menominee County in Wisconsin had the highest rate, at 36 percent.

Vinson said family physicians are particularly well-positioned to focus on the communities they serve, and he recommended that if an FP's county is listed as having a high rate of binge drinking,( that should definitely heighten the need to broach the subject with patients.

Vinson also noted that the increased rate of binge drinking in women signals the importance of highlighting to patients that binge drinking isn't just a problem among young men.

What Are Current Recommendations?

The U.S. Preventive Services Task Force recommends( screening adults age 18 and older for alcohol misuse and providing those engaged in hazardous drinking with brief behavioral counseling interventions to reduce misuse. But the group found insufficient evidence to assess the benefits and harms of screening and behavioral counseling in primary care settings to reduce alcohol use among adolescents. The AAFP largely mirrored these recommendations, noting that although it recognizes avoidance of alcohol products by adolescents ages 12 to 17 is desirable, the effectiveness of the physician's advice and counseling in this area is uncertain.

Vinson added that any patient visit for an injury or injury follow-up should prompt an inquiry about drinking and drug use. "This is because the No. 1 modifiable risk factor for injury is alcohol use," he said.

As for Vinson's opinion on screening for alcohol misuse in general: "It is something that we should do, and it's not that hard to do. A single question will pick up the problem most of the time."

Related AAFP News Coverage
AAFP Issues Final Recommendation on Screening, Counseling for Alcohol Misuse

Alcohol Screening Guide Helps Family Physicians Target Teens Who May Need Help
Substance Abuse Can Be Stopped Before It Starts, Says FP


More From AAFP
American Family Physician: Adolescent Substance Use and Abuse: Recognition and Management

American Family Physician: Adolescent Health Screening and Counseling

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