WEDNESDAY, March 25, 2015 (HealthDay News) -- Students at schools that impose suspensions for marijuana use are more likely to smoke pot than those at schools without a suspension policy, a new study finds.
Researchers also found that counseling was much more effective in reducing marijuana use than suspensions.
"To reduce marijuana use among all students, we need to ensure that schools are using drug policies that respond to policy violations by educating or counseling students, not just penalizing them," study co-author Richard Catalano, a professor of social work at the University of Washington, said in a university news release.
The researchers examined the effects of drug policies among more than 3,200 seventh and ninth graders at schools in Washington state and in Victoria, Australia.
Students at schools that handed out suspensions for drug use were nearly two times more likely to use marijuana in the next year than students at schools without suspension policies. This was true among all students, not just those who were suspended, the researchers said.
"That was surprising to us," said Catalano.
"It means that suspensions are certainly not having a deterrent effect. It's just the opposite," he added.
But the researchers also found that students at schools that referred marijuana users to a school counselor were nearly 50 percent less likely to use marijuana in the next year.
Other policies -- such as calling the police, expelling students, or referring them to a school nurse -- had no notable effect on marijuana use, according to the study published online recently in the American Journal of Public Health.
The American Academy of Child & Adolescent Psychiatry has more about teens and marijuana.