Marijuana is the most common illicit drug used in the United States. Prior to 2007, marijuana use was on the decline. However, since that time, its use has been increasing. At the same time, young people are less likely to disapprove of marijuana use and to think it is harmful. The growing belief that marijuana is a safe drug may be the result of recent public discussions about medical marijuana and the public debate over the drug’s legal status. In addition, some believe marijuana cannot be harmful because it is “natural.” But not all natural plants are good for you—take tobacco, for example.
Graph from DrugAbuse.gov