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Neuroscientists at Georgetown University Medical Center (GUMC) are zeroing in on brain factors and behaviors that put teens at risk of alcohol use and abuse even before they start drinking.
Four abstracts from the Adolescent Development Study exploring these factors will be presented at Neuroscience 2014, the Society for Neuroscience's annual meeting in Washington. The Adolescent Development Study, a collaboration between the University of Maryland School of Medicine (UMSOM) and GUMC funded by the National Institutes of Health (NIH), is a wide-ranging effort to understand how a teen brain "still under construction," as the NIH puts it, can lead to risky behaviors such as alcohol and drug use.
One abstract provides new evidence that adolescents at higher risk of alcoholism have reduced connections in key brain networks; another links impaired brain connections to impulsivity; and two abstracts examine impulsivity in relation to sugar intake and intake of DHA, an essential omega-3 fatty acid.
"What this study is attempting to do is identify the differences in the brains of adolescents who go on to misuse alcohol and other drugs," says VanMeter. "If we know what is different, we may be able to develop strategies that can prevent the behavior."
The studies were conducted with a participant pool of 135 preteen and teenage boys and girls with an average age of 12.6 years. All underwent structural and functional MRI to investigate the connection between brain development and behavior. Other tools the researchers used include questionnaires and several tests of neurocognitive function, including two tests used specifically while adolescents were scanned - the Continuous Performance Task (CPT), which measures impulsivity, and the Temporal Discounting Task (TD), which quantifies preference for immediate rather than delayed reward.
The first study examines a long-standing question: is lack of connectivity in the brain's Executive Control Network (ECN) a contributor to, or the result of, teen alcohol use?
Tomas Clarke, a research assistant and Stuart Washington, PhD, a post-doctoral fellow in VanMeter's laboratory, looked at the association between the Drug Use Screening Inventory questionnaire filled out by the 32 participants' parents and brain connectivity within the ECN, which includes the areas that process emotion, impulsivity and self-control.
The questionnaire is predictive of future alcohol misuse. It does not ask parents about their alcohol or drug use but probes social behaviors in their children such as irritability, anger, sadness, etc.
Clarke divided the participants into two groups--16 at high/medium risk for alcohol abuse, based on the test, and 16 at low risk. He then used fMRI scans to look at connectivity in the ECN. He found ECN connectivity was significantly lower in the high/medium risk groups compared to the low risk group.
"We know impaired functioning in the ECN is linked to an earlier age of drinking onset and higher frequency of drinking, but it was unclear whether this dysfunction occurred before drinking or was a consequence of alcohol use," Clarke says. "Our findings suggest reduced prefrontal cortex development predates alcohol use and may be related to future alcohol use disorders."
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Category(s):Addictions, Child and/or Adolescent Issues, Child Development
Source material from Georgetown University Medical Center
