Cigarette smoking, but not behavioral problems, independently and consistently predicted the use of marijuana by adolescents in a new study. The finding came from a study of more than 1,600 Dutch youngsters who were assessed at ages 10 to 12 and again at ages 12 to 15 and 15 to 18. The results showed that the association between what the researchers called externalizing behavior problems — conduct, attention deficit/hyperactivity and oppositio ... Jump to full article >>