EXECUTIVE HIGHLIGHTS: Colorado and Washington legalized marijuana in 2012, followed by Alaska and Oregon in 2014. The District of Columbia legalized cultivation and possession in 2014. Today’s highly potent marijuana represents a growing and significant threat to public health and safety, a threat that is amplified by a new marijuana industry intent on profiting from heavy use. State laws allowing marijuana have, in direct contradiction to federal law, permitted this industry to flourish, influencing both policies and policy makers. While the consequences of these policies will not be known for decades, early indicators are troubling. This report, reviewed by prominent scientists and researchers, serves as an evidence-based guide to what we currently observe in various states.