Please use this link to access this publication. Abstract Study objectives Rates of cannabis use disorder (CUD) appear to be increasing nationally, with increases greater in states that legalized cannabis use. However, as legalization has progressed and stigma declined, some of these apparent increases could be due to greater willingness of survey respondents and patients to acknowledge cannabis involvement. Biological indicators of cannabis use overcome some concerns about trends denoted by self-report data whose validity is potentially changing over time. Our objective was to investigate the relationship between medical cannabis laws (MCL) and recreational cannabis laws (RCL) and the prevalence of cannabis-positive urine...