The legality of cannabis for medical and recreational use varies by country, in terms of its possession, distribution, and cultivation, and (in regards to medical) how it can be consumed and what medical conditions it can be used for. These policies in most countries are regulated by three United Nations treaties: the 1961 Single Convention on Narcotic Drugs, the 1971 Convention on Psychotropic Substances, and the 1988 Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic Substances. Cannabis is classified as a Schedule I drug under the Single Convention treaty, meaning that signatories can allow medical use but that it is considered to be an addictive drug with a serious risk of abuse.