Background Habitual behavior and attentional bias are distinct cognitive processes that both contribute to inflexible behavior and are commonly observed in addiction. While animal studies provide strong evidence for an association between adolescent alcohol use and impairments in behavioral flexibility in adulthood, such a link in human research has not yet been explored. Moreover, since reduced flexible behavior serves as a risk factor for escalating alcohol intake, continued alcohol consumption use in adulthood may further exacerbate any deficits associated with adolescent drinking.

Methods We used principal component analysis to create composite scores for adolescent and past year alcohol use, based on self-report measures from a healthy adult sample. Group differences in alcohol use were examined in relation to habitual responding (n=71) and attentional bias (n=44) toward non-drug reward cues, using two behavioral flexibility tasks. We used linear regression analyses to explore associations between past year alcohol use and behavioral flexibility outcomes in adults with histories of light versus heavy adolescent alcohol use.

Results Heavy adolescent alcohol use was characterized by earlier drinking onset and higher binge-drinking frequency before age 18. Adults with a history of heavy adolescent alcohol use demonstrated significantly greater habitual responding compared to those with lighter use. Among this group, greater past year alcohol use was also associated with increased difficulty disengaging attention from non-drug reward cues.

Conclusions These results indicate that adolescent and current alcohol use may differentially impact habitual responding and attentional bias towards non-drug reward cues. Notably, this is the first human study to explore both aspects of behavioral inflexibility in relation to different periods of alcohol use within the same adult sample.

The authors have declared no competing interest.

This work was supported by Award Numbers P60AA011605 (CAB & DLR), T32DA007244 (EMV & MMR), T32AA007573 (EMV), and F31AA028427 (MMR) from the National Institutes of Health.

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IRB of University of North Carolina at Chapel Hill gave ethical approval for this work.

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