Youth who start smoking before they enter their teens are far more likely to smoke pot before they’re out of them, according to a new Finnish-American study. The study found that kids who started smoking tobacco by age 12 were 26 times more likely to smoke weed by the time they were 17. “The findings support the gateway hypothesis, which asserts that illicit substances such as tobacco and alcohol are a stepping stone to harder, illicit drugs,” says project team member Tellervo Korhonen from the University of Helsinki. (HealthDay)
http://health.usnews.com/health-news/family-health/childrens-health/articles/2011/03/28/teens-who-smoke-early-often-try-pot-later-study-finds