Myth Busters
CDC: Teen cannabis use dropped in Colorado and other states after legalization
Two possible reasons cited by the CDC for the decline or absence of youth marijuana use were that cannabis lost its novelty appeal and the reduction of the illegal market in states where cannabis is regulated.
Washington State University: Legal cannabis has not led to spikes in crime in WA and CO
Researchers found that legalizing marijuana had “no statistically significant long-term effects” on serious violent crime and property crime rates in either state.