and proven. The FDA has thus not approved CBD for any other medical use; however, the 2018 farm bill legalized CBD extracted from hemp (less than 0.3% THC) at the federal level. The legality of CBD products also varies by state, and in some jurisdictions prohibition is not strictly enforced. Effects of legalizing medical cannabis A 2016 study found significant drops in violent crime in states that have legalized medical cannabis. A 2017 study similarly found that introduction of medical cannabis laws caused a reduction in violent crime in American states that border Mexico. A 2018 study found that legalizing medical cannabis in some states made residents of neighboring states increasingly tolerant toward cannabis regulation. A 2013 study found that medical cannabis legalization is associated with an 8-11% reduction in traffic fatalities. Several studies have found decreased rates of opioid use and abuse in states that have legalized medical cannabis. Several studies have found no increase in teen use in states that have legalized cannabis for medical purposes. A 2018 meta-analysis in the journal Addiction similarly found no increase. Qualifying conditions Below is a comparison of medical conditions for which doctors can recommend cannabis in each state or territory. The table does not include all approved conditions and could contain outdated information. Low-THC, high-CBD states are not listed. Data additionally obtained from Leafly and ProCon.org. Reciprocity Many states have reciprocity laws that recognize out-of-state registrations for medical cannabis patients. Below is a list of reciprocity policies as of October 8, 2021. See also Legal history of cannabis in the United States Timeline of cannabis laws in the United States Legality of cannabis by U.S. jurisdiction Legalization of non-medical cannabis in the United States Removal of cannabis from Schedule I of the Controlled Substances Act History of medical cannabis Notes References External links State Medical Marijuana Laws (National Conference of State Legislators) Cannabis in the United States Cannabis law in the United States Cannabis law reform in the United States Drug control law in the United States Drug policy of the United States Medicinal use of cannabis Federalism in the United States