As the scientific community begins to disentangle the effects of marijuana legalization/ commercialization, certain US states present unique scientific opportunities. Colorado is a case in point. For example, Colorado not only maintains a medical marijuana registry but also posts summary information to the Colorado Department of Public Health and Environment (CDPHE) website, allowing monitoring of temporal trends. In many other states it is difficult to assess the impact of medical marijuana laws and policy change because they do not maintain a medical marijuana registry (e.g., Washington), the state registry is voluntary (e.g., California), or information from the registry is not made available to the public (e.g., Hawaii; Bowles, 2012). Although in November, 2000, with the passage of Amendment 20 to the state constitution, Colorado legalized marijuana for medical purposes, review of the CDPHE records supports that from June, 2001 through January, 2009 only 6,369 new patient applications were received by the CDPHE. In 2009 there was a confluence of three major policy decisions: (1) Attorney General Eric H. Holder Jr. announced an end to raids on distributors of medical marijuana
