Alcohol's Damaging Effects On Adolescent Brain Function

"The adolescent brain is a 'work in progress,'" said Peter M. Monti, symposium organizer and professor of medical sciences and director of the Center for Alcohol and Addiction Studies at Brown University. "It is often referred to as 'plastic' because it is built to acquire information, adapt, and learn. Alcohol, however, can disrupt the adolescent brain's ability to learn life skills. So, not only can heavy drinking during this time get the adolescent into trouble through behavior such as risk taking or drinking and driving, but it can also make the brain less able to learn important life skills that can help one avoid trouble as an adult."

Monti added that another important aspect of the symposium was its intent to "bridge the gap" between two quickly evolving but generally disparate areas of research, animal and human. "This is the first time we've pulled together neurobiological, behavioral and psychological mechanisms that are related to drinking in both human and animal models," he said. "What is called 'transdisciplinary science' is very hot right now; it refers to when you bring together experts from across different fields to sort of push the science further."

Some of the findings presented were:

# The neurochemical, cellular, synaptic, and structural organization of the adolescent brain makes it more vulnerable than the adult brain to disruption from activities such as binge drinking. Adolescent rats that were exposed to binge drinking appear to have permanent damage in their adult brains.

# Research has identified subtle but important brain changes occurring among adolescents with Alcohol Use Disorder (AUD), resulting in a decreased ability in problem solving, verbal and non-verbal retrieval, visuospatial skills, and working memory.

"AUD is a term that encompasses both of the diagnostic categories of alcohol abuse and alcohol dependence," said Monti. "These findings with kids really raise the possibility that as heavy drinking continues, the likelihood of neuronal damage increases, because the brain is no longer is able to compensate for the disruption caused by alcohol."

# The association between antisocial behavior during adolescence and alcoholism may be explained by abnormalities in the frontal limbic system, which appears to cause "blunted emotional reactivity."

"The 'emotional reactivity' concept is fairly novel in this context," said Monti. "Scientific findings suggest that certain behavioral patterns shown by kids and adolescents with conduct disorder – such as persistent, impulsive and aggressive behavior, lack of adherence to societal norms, etc. – may be a marker for underlying problems in emotional reactivity and related impairment in frontal limbic processes. This underlying dysfunction in central processes serving emotional reactivity, seen as poor self control, impaired decision making, and poor behavioral regulation, may in part explain why kids with conduct problems are especially prone to substance-abuse disorders."

# Alcohol-induced memory impairments, such as "blackouts," are particularly common among young drinkers and may be at least in part due to disrupted neural plasticity in the hippocampus, which is centrally involved in the formation of autobiographical memories.

# The symposium concluded that many serious adult mental disorders have their onset during childhood, and are risk factors for heavy alcohol involvement, especially attention deficit hyperactivity disorder, schizophrenia spectrum disorders, and bipolar spectrum disorders. The nature and extent of alcohol's effects on the neurodevelopmental and clinical aspects of these disorders should be a priority.

"I want to emphasize the complexity of this problem, the effects of alcohol on the adolescent brain, and the need to bring 'transdisciplinary and translational science' to bear on it," said Monti. "I don't think the problem can only be solved by people in neuropsychology, or clinical psychology, or neurobiology, or genetics. I think it's going to require a transdisciplinary approach; hopefully we've taken it a step in that direction with this symposium."

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Alcoholism: Clinical & Experimental Research (ACER) is the official journal of the Research Society on Alcoholism and the International Society for Biomedical Research on Alcoholism. Co-authors/presenters of the symposium proceedings published in the ACER paper, "Adolescence: Booze, Brains, and Behavior," were: Robert Miranda, Jr. of the Center for Alcohol and Addiction Studies at Brown University; Kimberly Nixon and Fulton T. Crews of the University of North Carolina; Kenneth J. Sher of the University of Missouri and the Midwest Alcoholism Research Center; H. Scott Swartzwelder and Aaron White of Duke University Medical Center and Durham VA Medical Center; and Susan F. Tapert of the VA San Diego Healthcare System and the University of California, San Diego. The research was funded by the Department of Veterans Affairs, the National Institute on Alcohol Abuse and Alcoholism, the Institute for Medical Research, and the National Institute on Drug Abuse.