A Cohort-Based Examination of Marijuana Use and Disapproval Among American Youth from Early Adolescence to Young Adulthood

Background and Purpose.  In the wake of large-scale changes in public perception and policy related to marijuana use, a bevy of recent studies and reports have examined changes in the use and perception of marijuana among youth in the United States. However, prior research has often overlooked potential cohort effects on marijuana use and disapproval patterns across adolescence and young adulthood. We address this critical gap by examining the use and the disapproval of marijuana across multiple cohorts of American youth in a national sample.

Methods.  Findings are based on repeated, cross-sectional data collected annually from adolescents (ages 12-17; n = 216,852) and young adults (ages 18-21; n = 114,131) surveyed as part of the National Survey on Drug Use and Health between 2002 and 2013. For each of the birth years between 1985 and 1997, we combined a series of nationally representative cross-sections of youth to provide multi-year strings of data that, in effect, reflect nationally representative cohorts (based on respondent age/survey year). To assess cohort differences, we report the prevalence estimates and corresponding 95% confidence intervals for marijuana disapproval and past year marijuana use among the birth cohorts (1985-1997) from early adolescence to young adulthood (ages 12-21).We primarily emphasize the birth cohorts from 1988 and 1994 while also presenting data from the 1991 cohort as a midway point. These groups were identified as the cohorts that provided the optimal combination of spacing in years (i.e., a multi-year gap between each of the cohorts) and inclusion of multiple ages (i.e., maximum coverage of ages 12-21).

Results. Across all cohorts, we observed a marked drop in marijuana disapproval and increase in marijuana use as youth moved from the early-to-mid adolescent to young adult stage. However, important cohort differences were observed. Compared to the 1988 cohort, youth from the 1994 birth cohort reported significantly higher levels of marijuana disapproval during the early adolescent years (Age 14: 1988 = 64.4%, CI = 63.0-65.7; 1988 = 70.4%, CI = 68.6-72.1) and lower levels of disapproval during the young adult years (Age 19: 1988 = 32.0%, CI = 30.4-33.7; 1994 = 25.0%, CI = 23.5-26.6). Additionally, youth in the 1994 cohort reported significantly lower levels of marijuana use during the early adolescent years (Age 14: 1988 = 11.8%, CI = 10.7-13.0; 1994 = 8.5%, CI = 7.6-9.5) and significantly higher levels of marijuana use as young adults (Age 18: 1988 = 30.5%, CI = 28.8-32.3; 1994 = 35.1%, CI = 33.2-37.1).

Conclusions. We identified a clear pattern of cohort differences in which youth born in 1994 report—relative to youth born in 1988—greater marijuana disapproval and lower marijuana use during early-to-mid adolescence in combination with relatively lower disapproval and greater use during the young adult years. While further research is needed to identify the factors influencing youth marijuana use and perception, findings suggest that increasingly permissive marijuana policies and public perceptions may have uniquely impacted the marijuana use trajectories of the cohort of youth coming-of-age at the height of the marijuana revolution.