Explaining Continuity and Discontinuity in Problematic Alcohol Use from Mid-Adolescence to Age 25

Alcohol misuse in adulthood is a leading cause of morbidity and mortality. Alcohol-related problems in adolescence are strongly related to misuse in adulthood, however, significant discontinuity exists. The factors that contribute to discontinuity in problematic alcohol use (e.g., problems early but not later) are poorly understood. Yet, insight into these factors holds considerable potential to improve treatment and preventive interventions and inform policy. Prior work on the International Youth Development Study (IYDS) has shown that the levels of risk and protective factors for adolescent drinking vary across Washington State (WA) and the State of Victoria (VIC) in Australia, but that their longitudinal relationship to drinking is largely similar despite these level differences and differences in alcohol policy (zero tolerance vs. harm minimization). The degree to which alcohol policy moderates the impact of early alcohol problems on later heavy alcohol use is unclear. The present study asks what factors influence continuity and discontinuity between adolescent alcohol-related problems and alcohol misuse at age 25, and whether these explanatory factors operate in the same way in two countries with different alcohol policy.

Data are drawn from the IYDS, a gender-balanced, multiethnic, statewide representative sample of 7^th grade students in WA and VIC in 2002 (n = 1,958). Data were collected at ages 13-15 and 25 (2014, 87% retention). Early alcohol problems (ages 13-15) included blackouts, violence/fights, trouble at school/home, and being unable to stop drinking. Alcohol misuse at age 25 was measured using the Alcohol Use Disorders Identification Test (AUDIT).

Rates of early alcohol problems were significantly higher in VIC (44% vs 30% in WA), as were rates of risky or harmful drinking at age 25 (29% vs 17% in WA). About 32% of those who reported early alcohol problems also reported risky or harmful drinking at age 25 (continuity); 18% of those without early alcohol problems reported risky or harmful drinking at age 25 (discontinuity). Factors related to continuity in alcohol problems included maternal education, sex, and age 25 employment. Factors related to discontinuity (no early problems, but later risky/harmful use) included age 25 family conflict and homelessness. Additional analyses will examine other factors that may contribute to discontinuity and test for cross-national differences.

These findings support the benefit of zero tolerance alcohol policies as compared to harm minimization for reducing early alcohol problems and adult alcohol misuse. Implications for interventions and policy aimed at interrupting continuity in alcohol problems and for preventing development of later misuse among youth without problems will be discussed.