Although drinking by U.S. adolescents has decreased during the last decade, more than 20 percent of U.S. high-school students continue to drink alcohol before the age of 14 years. This can have adverse effects on their neurodevelopment. For example, youth who initiate drinking before 14 years of age are four times more likely to develop psychosocial, psychiatric, and substance-use difficulties than those who begin drinking after turning 20 years of age. Little is known about how the age of alcohol-use onset influences brain development. This is the first study to assess the association between age of adolescent drinking onset and neurocognitive performance, taking into account pre-existing cognitive function.
The researchers examined data from a longitudinal study on the neurocognitive effects of substance use in adolescents: 215 adolescents (127 boys, 88 girls) with minimal alcohol use experience were administered a neuropsychological test battery, which was repeated an average of 6.8 years later. Analyses examined whether earlier ages of onset for first and weekly alcohol use adversely affected neurocognition, controlling for substance-use severity, and familial and social environment factors.
Results showed that an earlier onset of drinking increases the risk for alcohol-related neurocognitive vulnerabilities, and that the initiation of any or weekly alcohol use at younger ages is a risk factor for poorer, subsequent neuropsychological functioning. More specifically, an earlier age of onset of first drinking predicted poorer performance in the domains of psychomotor speed and visual attention, and an earlier age of onset of weekly drinking predicted poorer performances on tests of cognitive inhibition and working memory. The authors suggested that these findings have important implications for public policies related to the legal drinking age and prevention strategies and further research on these effects is warranted.