Marijuana

https://www.sciencedaily.com/releases/2016/05/160524144915.htm

Source: Washington University School of Medicine

Summary: A survey of more than 216,000 adolescents from all 50 states indicates the number of teens with marijuana-related problems is declining. Similarly, the rates of marijuana use by young people are falling despite the fact more US states are legalizing or decriminalizing marijuana use and the number of adults using the drug has increased.