Dilley JA, et al. - Data from the nationally representative Monitoring the Future survey (MTF) were analyzed to determine the prevalence of cannabis use in youths after legalization in Washington state. Since the MTF is not intended to provide state-representative estimates, the article generated estimates of covariate-adjusted prevalence models for each state. A complex association was suggested between legalization and cannabis use among youths: increases in prevalence among Washington 8th and 10th graders, but not among 12th graders, relative to use in states without legalization of recreational marijuana.