They are also at greater risk of getting lung infections like pneumonia. Not everyone who uses marijuana becomes addicted. But, when a user begins to seek out and take the drug compulsively, that person is said to be dependent or addicted. According to one study, marijuana use by teenagers who have prior serious antisocial problems can quickly lead to dependence on the drug. Some frequent, heavy users of marijuana develop a tolerance for it.
Some young people use it because they see older people in the family using it.
Others may think it's cool to use marijuana because they hear songs about it and see it on TV and in movies. Some teens may feel they need marijuana and other drugs to help them escape from problems at home, at school, or with friends. Among students surveyed in a yearly national survey, only about one in five 10th graders report they are current marijuana users. Fewer than one in four high school seniors is a current marijuana user. You don't have to use marijuana just because you think everybody else is doing it.