Substance Use Among Youth in Washington State from 2008 to 2016: Associations with School-Level Graduation Rates and Race/Ethnicity

During the past decade Washington State has loosened restrictions on cannabis, raising concerns about effects on substance use (SU) among adolescents, particularly adolescents already at risk for adverse health outcomes. Adolescents at higher risk include students in disadvantaged schools marked by low educational attainment Further, given the disproportionate racial/ethnic distribution in low performing schools, the impact of school-context may be particularly felt by students of color, who are already at higher risk. We link statewide biennial Washington State Healthy Youth Survey cross-sectional data spanning 2008-2016 from 255,718 students in 10^th Grade in 379 high schools with data from the Office of Superintendent of Public Instruction to examine the independent and joint associations of school-level graduation rates, race/ethnicity (RE), and historical time with student-level likelihood of different margins of SU. Findings from multilevel models indicate that, overall, prevalence of any and frequent alcohol and cigarette use decreased substantially over time, and cannabis use decreased slightly. Any and frequent SU of all types was more prevalent in schools with lower average graduation rates across the study period (e.g., a 5% higher graduation rate was associated with 13.5% lower odds of frequent cannabis use, i.e., using 6 or more times in the prior month). This association between school-level graduation rate and frequent cannabis use grew slightly stronger over time. There were RE differences in the prevalence of any and frequent SU, with Asian and White students less likely to report any and frequent SU compared to other students of color, but there were few differential trends in SU by RE over time. Although males were more likely to report cannabis use, this gap decreased over time. The association of high school graduation rate with SU differed by RE with the association being weaker for Black, Hispanic, and Pacific Islander students than White students. Interestingly, prevalence of any and frequent cannabis use increased in rural Washington districts relative to Puget Sound region containing urban centers of Seattle, Bellevue, Tacoma, and Olympia. The findings point to elevated risk for SU among students at low performing schools and students of some RE groups, but do not point to clear differential changes in substance use during a period of loosening cannabis restrictions. Implications for prevention programming aimed at curbing adolescent substance use, particularly in the context of state-wide legalization of cannabis, will be discussed.