A longitudinal examination of adolescent response inhibition: neural differences before and after the initiation of heavy drinking.

RATIONALE: Response inhibition abnormalities contribute to several maladaptive behaviors commonly observed during adolescence, including heavy drinking.
OBJECTIVES: The present study aimed to determine whether abnormalities in brain response during response inhibition predate or follow adolescents' transition into heavy drinking, which is pivotal in identifying the neural antecedents and consequences of adolescent alcohol use.
METHODS: Longitudinal functional magnetic resonance imaging (fMRI) acquired during a response inhibition task was collected on adolescents before the onset of heavy drinking and then again on the same scanner approximately 3 years later. Adolescents who transitioned into heavy drinking (n = 20) were matched to continuously nondrinking adolescents (n = 20) on baseline and follow-up demographic and developmental variables.
RESULTS: During no-go relative to go trials, participants showed responses common to inhibitory circuitry: frontal (e.g., pre-supplementary motor area), temporal, and parietal regions. A repeated measures analysis of covariance revealed that adolescents who later transitioned into heavy drinking showed less fMRI response contrast at baseline than continuous nondrinkers in frontal, parietal, subcortical, and cerebellar regions (p < 0.01, clusters >756 μl), then increased activation after the onset of heavy drinking in frontal, parietal, and cerebellar areas.
CONCLUSIONS: Future heavy drinkers showed less activation of inhibitory circuitry before the onset of heavy drinking. After transitioning into heavy drinking, they showed more activation during response inhibition than nondrinking controls. These results contribute to the growing literature suggesting that neural vulnerabilities exist prior to the onset of substance use, and the initiation of heavy drinking may lead to additional alterations in brain functioning.