Finally, a fundamental hypothesis that guides our work is that age-by-use interactions will be present. Neurodevelopment is more pronounced earlier versus later in the adolescent period (15,16,20). Thus, it is expected that neural circuitry will be most impacted in individuals who initiate use earlier versus later in the typical developmental course. We expect to be able to examine, with subsequent assessment waves, how the timing of initiation impacts the status of this circuitry in young adulthood after the adolescent-limited use has abated. This is important because adolescent alcohol use is widespread and the extent to which brain structure normalizes with abstinence is unclear (7). None of the participants in this study were diagnosed with alcohol dependence at the follow-up assessment, and few met formal diagnostic criteria for alcohol abuse. Their self-reported use patterns are similar to what might be described as “typical” for the United States adolescent population. As suggested here by emerging differences in self-reported behavioral control over time in alcohol use initiators, those impacts are likely to be neurodevelopmental but also behavioral. Behavioral effects associated with subclinical patterns
