Adolescent brains respond to risky situations differently if the teen's parents are alcoholics, new research finds.
While preceding studies have shown that adolescents with a family history of alcoholism (FHP) are at a risk for developing alcohol-abuse disorders and that drinking increases risky decision-making, the new study is the first to look at risk-taking behaviors among FHP teens who have never drunk alcohol themselves.
(The researchers defined family history of alcoholism as those teens with at least one biological parent with a history of alcohol abuse and/or alcohol dependence, or those with two or more second-degree relatives meeting this condition on either the maternal or paternal side of the family.)
"A previous study looked at young adults who were drinkers, therefore, it is hard to say if the differences found were purely a pre-existing neural risk factor for alcohol use," study researcher Megan Herting of Oregon Health & Science University said in a statement.
Researchers studied 31 teens between the ages of 13 and 15 from the Portland, Ore., area. Thirteen of the subjects had no family history of alcoholism, also known as a negative family history of alcoholism (FHN), while 18 had a family history of alcoholism. All the subjects had little to no experience with drinking alcohol prior to their participation in the study.
Researchers used functional magnetic resonance imaging (fMRI) to examine the teens' brain activity responses during a decision-making task that presented risky versus safe probabilities of winning different amounts of money.
The researchers did not find significant differences in task performance among teens, regardless of their family history of alcoholism, but the fMRI scans showed that two areas of FHP teens' brains responded differently during the tasks.
"These areas were in the prefrontal cortex and cerebellum, both of which are important for higher-order day-to-day functioning, such as decision-making," said study researcher Bonnie J. Nagel, assistant professor of psychiatry and behavioral neuroscience at Oregon Health & Science University.
"In these brain regions, FHP adolescents showed weaker brain responses during risky decision-making compared to their FHN peers," Nagel said.
The researchers suggest a weaker activation of these decision-making areas of the brain may pose an increased vulnerability toward risky decisions involving future alcohol use among FHP individuals who are already at risk for alcoholism.
"Taken together with other studies on FHP youth, these results suggest that atypical brain structure and function exist prior to any substance use, and may contribute to an increased vulnerability for alcoholism in these individuals," Nagel said.
However, the researchers noted that there are many different genetic and environmental factors involved in forming and influencing an individual's risk of future alcohol abuse. They added that, in order to help develop better prevention programs, further research is needed to determine the relative influence of specific traits on alcohol-abuse risk.