Those favoring strict drug laws believe that, as marijuana becomes more available and less stigmatized, teen drug use will go up. It's a straightforward and logical belief. The reality is that, to date, not one jurisdiction, either in the U.S. or elsewhere, has seen a marked increase in teen drug use following the relaxation of marijuana restrictions. Not one. Both Colorado and Washington, the pioneer states of marijuana legalization, have actually seen drops in teen marijuana use following legalization. The drop in Colorado was particularly dramatic. Despite the wave of legalization, nationwide, teen drug use is at a 20-year low.