No 'smoking' gun -- Research indicates teen marijuana use does not predict drug, alcohol abuse

Marijuana is not a "gateway" drug that predicts or eventually leads to substance abuse, suggests a 12-year University of Pittsburgh study. The study, which found that young men who chose to initiate their drug use with marijuana were no more likely to go on to abuse drugs or alcohol than those who smoked or drank first, calls into question the long-held belief that has shaped prevention efforts and governmental policy for six decades.