Reasons for alcohol use from 1976 to 2020 in the United States among individuals aged 18 to 30: Historical changes and mediation of cohort effects in binge drinking

BackgroundAlcohol use is declining among US adolescents/early young adults and increasing among other adults, with increases in adult binge drinking more concentrated in females than males. Reasons for drinking are historically patterned by age and sex, and if historically variant, could suggest that changes over time could in part explain age- and sex-differential cohort effects.MethodsWe analyzed longitudinal Monitoring the Future data for individuals born from 1958 to 1990. These individuals were aged 29/30 from 1987 to 2020, and first surveyed at age 18 from 1976 to 2008 (N = 14,190). Five reasons for drinking were analyzed (social, enhancement, avoid problems, relax, boredom). Drinking for social reasons and to relax were most prevalent. Total effects of birth cohort predicting past-2-week binge drinking were estimated with polynomial regression models by age; indirect effects through mediators were estimated.ResultsDrinking reasons exhibited dynamic time trends across birth cohort and sex. Notable increases were observed in social reasons: among women aged 29/30, social reasons increased from 53% to 87% from 1987 to 2020. Social reasons to drink had prominent positive indirect effects at adult ages (age 23/24 and above among men; age 19 and above among women), indicating that binge drinking would have increased less were it not for the increase in social reasons for drinking. Social reasons also mediated adult male/female differences, indicating that part of the reason sex differences are diminishing is the more rapid increases in social reasons for drinking among women. Indirect effects were also observed for drinking to relax and for boredom, and limited indirect effects were observed for enhancement and to avoid problems.ConclusionChanging endorsement of drinking reasons, especially social reasons, among US adult drinkers mediate cohort effects in binge drinking in the US adult population and explain in part why binge drinking is converging by sex.