Longitudinal effects of school drug policies on student marijuana use in Washington State and Victoria, Australia.

OBJECTIVES: We examined the longitudinal effect of schools' drug policies on student marijuana use. METHODS: We used data from the International Youth Development Study, which surveyed state-representative samples of students from Victoria, Australia, and Washington State. In wave 1 (2002), students in grades 7 and 9 (n = 3264) and a school administrator from each participating school (n = 188) reported on school drug policies. In wave 2 (2003), students reported on their marijuana use. We assessed associations between student-reported and administrator-reported policy and student self-reported marijuana use 1 year later. RESULTS: Likelihood of student marijuana use was higher in schools in which administrators reported using out-of-school suspension and students reported low policy enforcement. Student marijuana use was less likely where students reported receiving abstinence messages at school and students violating school policy were counseled about the dangers of marijuana use. CONCLUSIONS: Schools may reduce student marijuana use by delivering abstinence messages, enforcing nonuse policies, and adopting a remedial approach to policy violations rather than use of suspensions.