Objective: This article reviews the literature on adolescent brain development and considers the impact of these neural alterations on the propensity to use and misuse alcohol. Methods: Neural, behavioral and hormonal characteristics of adolescents across a variety of species were examined, along with a review of the ontogeny of ethanol responsiveness, tolerance development and stress/alcohol interactions. Results: The adolescent brain is a brain in transition. Prominent among the brain regions undergoing developmental change during adolescence in a variety of species are the prefrontal cortex and other forebrain dopamine projection regions, stressor-sensitive areas that form part of the neural circuitry modulating the motivational value of alcohol and other reinforcing stimuli. Along with these characteristic brain features, adolescents also exhibit increased stressor responsivity and an altered sensitivity to a variety of ethanol effects. Findings are mixed to date as to whether exposure to ethanol during this time of rapid brain development alters neurocognitive function and later propensity for problematic ethanol use. Conclusions: Developmental transformations of the adolescent brain may have been evolutionarily advantageous in promoting behavioral adaptations to avoid inbreeding and to facilitate the transition to independence. These brain transformations may also alter sensitivity of adolescents to a number of alcohol effects, leading perhaps in some cases to higher intakes to attain reinforcing effects. These features of the adolescent brain may also increase the sensitivity of adolescents to stressors, further escalating their propensity to initiate alcohol use. Additional investigations are needed to resolve whether ethanol use during adolescence disrupts maturational processes in ethanol-sensitive brain regions.
