Schools where administrators report using out-of-school suspension to enforce drug policy and where students report low policy enforcement, regardless of the type of drug policy adopted, show an increased likelihood of marijuana use, according to new research from the American Journal of Public Health. Schools that used abstinence-based prevention and those that counseled students about the dangers of marijuana use showed a lower likelihood of marijuana use.

Researchers used data from the International Youth Development Study in which they analyzed results from 3,264 students in grades 7 and 9 from Washington state and Victoria, Australia. They also surveyed the school administrators of the 188 schools the students attended. Survey responses were reviewed from two waves in 2002 and 2003. Students and administrators were asked about school policies and enforcement and students self-reported on their marijuana use. Researchers sought to understand how student marijuana use is impacted by the type of drug policy adopted. They also investigated how strongly the school drug policy was enforced and the degree to which the policy was based on abstinence and harm minimization principles.

The study reveals that students who attended schools with policies of out-of-school suspensions for incidents of illicit drug use were 1.6 times more likely than students in schools without policies of out-of-school suspension to be users of marijuana the following year. This effect was observed for all students in the school and not just those who were suspended. In contrast, counseling and abstinence-based drug policies were associated with schools showing lower likelihood of marijuana use.

"Schools may reduce student marijuana use by delivering abstinence messages, enforcing non-use policies, and adopting a remedial approach for policy violations rather than use of suspensions" the researchers conclude.

"Importantly, these findings are robust across the two states with differing national contexts, showing for the first time the impact of school policy on marijuana use."

"It is important for schools and state and federal agencies to identify effective methods for preventing marijuana use," said lead author Tracy Evans-Whipp.

["Longitudinal effects of school drug policies on student marijuana use in Washington state and Victoria, Australia." Contact: Tracy J. Evans-Whipp, PhD, Centre for Adolescent Health, Murdoch Children's Research Institute, Victoria, Australia.]