Single Convention on Narcotic Drugs
The Single Convention on Narcotic Drugs of 1961 is an international treaty to prohibit production and supply of specific (nominally narcotic) drugs and of drugs with similar effects except under licence for specific purposes, such as medical treatment and research. As noted below, its major effects included updating the Paris Convention of 13 July 1931 to include the vast number of synthetic opioids invented in the intervening thirty years and a mechanism for more easily including new ones. From 1931 to 1961, most of the families of synthetic opioids had been developed, including drugs in whatever way related to methadone, pethidine, morphinans and dextromoramide and related drugs; research on fentanyls and piritramide was also nearing fruition at that point.
Earlier treaties had only controlled opium, coca, and derivatives such as morphine, heroin and cocaine. The Single Convention, adopted in 1961, consolidated those treaties and broadened their scope to include cannabis and drugs whose effects are similar to those of the drugs specified. The Commission on Narcotic Drugs and the World Health Organization were empowered to add, remove, and transfer drugs among the treaty's four schedules of controlled substances. The International Narcotics Control Board was put in charge of administering controls on drug production, international trade, and dispensation. The United Nations Office on Drugs and Crime (UNODC) was delegated the Board's day-to-day work of monitoring the situation in each country and working with national authorities to ensure compliance with the Single Convention. This treaty has since been supplemented by the Convention on Psychotropic Substances, which controls LSD, MDMA, and other psychoactive pharmaceuticals, and the United Nations Convention Against Illicit Traffic in Narcotic Drugs and Psychotropic Substances, which strengthens provisions against money laundering and other drug-related offenses.
As of February 2015, the Single Convention has 185 state parties. The Holy See plus all member states of the United Nations are state parties, with the exception of Chad, East Timor, Equatorial Guinea, Kiribati, Nauru, Samoa, South Sudan, Tuvalu, and Vanuatu.
Regulation of cannabis
The Single Convention places the same restrictions on cannabis cultivation that it does on opium cultivation. Article 23 and Article 28 require each Party to establish a government agency to control cultivation. Cultivators must deliver their total crop to the agency, which must purchase and take physical possession of them within four months after the end of harvest. The agency then has the exclusive right of "importing, exporting, wholesale trading and maintaining stocks other than those held by manufacturers."
In the United States, the National Institute on Drug Abuse fulfills that function. NIDA administers a contract with the University of Mississippi to grow a 1.5 acre (6,000 m²) crop of cannabis every other year; that supply comprises the only licit source of cannabis for medical and research purposes in the United States. Similarly, in 2000, Prairie Plant Systems was awarded a five-year contract to grow cannabis in the Flin Flon mine for Health Canada, that nation's licit cannabis cultivation authority.
Article 28 specifically excludes industrial hemp from these regulations, stating, "This Convention shall not apply to the cultivation of the cannabis plant exclusively for industrial purposes (fibre and seed) or horticultural purposes." Hemp-growing countries include China, Romania, France, Germany, Netherlands, UK, and Hungary.
There is some controversy over whether cannabis is "particularly liable to abuse and to produce ill effects" and whether that "liability is not offset by substantial therapeutic advantages," as required by Schedule IV criteria. In particular, the discovery of the cannabinoid receptor system in the late 1980s revolutionized scientific understanding of cannabis' effects, and much anecdotal evidence has come to light about the drug's medical uses. The Canadian Senate committee's report notes,
At the U.S.’s insistence, cannabis was placed under the heaviest control regime in the Convention, Schedule IV. The argument for placing cannabis in this category was that it was widely abused. The WHO later found that cannabis could have medical applications after all, but the structure was already in place and no international action has since been taken to correct this anomaly.
The Commentary points out the theoretical possibility of removing cannabis from Schedule IV:
Those who question the particularly harmful character of cannabis and cannabis resin may hold that the Technical Committee of the Plenipotentiary Conference was under its own criteria not justified in placing these drugs in Schedule IV; but the approval of the Committee's action by the Plenipotentiary Conference places this inclusion beyond any legal doubt. Should the results of the intensive research which is at the time of this writing being undertaken on the effects of these two drugs so warrant, they could be deleted from Schedule IV, and these two drugs, as well as extracts and tinctures of cannabis, could be transferred from Schedule I to Schedule II.
Cindy Fazey, former Chief of Demand Reduction for the United Nations Drug Control Programme, has pointed out that it would be nearly impossible to loosen international cannabis regulations. Even if the Commission on Narcotic Drugs removed cannabis from Schedule IV of the Single Convention, prohibitions against the plant would remain imbedded in Article 28 and other parts of the treaty. Fazey cited amendment of the Articles and state-by-state denunciation as two theoretical possibilities for changing cannabis' international legal status, while pointing out that both face substantial barriers.
In a 2002 interview, INCB President Philip O. Emafo condemned European cannabis decriminalization measures:
It is possible that the cannabis being used in Europe may not be the same species that is used in developing countries and that is causing untold health hazards to the young people who are finding themselves in hospitals for treatment. Therefore, the INCB's concern is that cannabis use should be restricted to medical and scientific purposes, if there are any. Countries who are party to the Single Convention need to respect the provisions of the conventions and restrict the use of drugs listed in Schedules I to IV to strictly medical and scientific purposes.
However, Kathalijne Buitenweg on the European Parliament's Committee on Citizens' Freedoms and Rights, Justice and Home Affairs issued a report on 24 March 2003 criticizing the Single Convention's scheduling regime:
These schedules show that the main criterion for the classification of a substance is its medical use. In view of the principle according to which the only licit uses is those for medical or scientific purposes (art. 4), plants or substances deprived of this purpose are automatically considered as particularly dangerous. Such is the case for cannabis and cannabis resin which are classified with heroin in group IV for the sole reason that they lack therapeutic value. A reason which is in any event disputable, since cannabis could have numerous medical uses.
There have been several lawsuits over whether cannabis' Schedule IV status under the Single Convention requires total prohibition at the national level. In 1970, the U.S. Congress enacted the Controlled Substances Act to implement the UN treaty, placing marijuana into Schedule I on the advice of Assistant Secretary of Health Roger O. Egeberg. His letter to Harley O. Staggers, Chairman of the House Committee on Interstate and Foreign Commerce, indicates that the classification was intended to be provisional:
Some question has been raised whether the use of the plant itself produces "severe psychological or physical dependence" as required by a schedule I or even schedule II criterion. Since there is still a considerable void in our knowledge of the plant and effects of the active drug contained in it, our recommendation is that marijuana be retained within schedule I at least until the completion of certain studies now underway to resolve the issue.
The reference to "certain studies" is to the then-forthcoming National Commission on Marijuana and Drug Abuse. In 1972, the Commission released a report favoring decriminalization of marijuana. The Richard Nixon administration took no action to implement the recommendation, however. In 1972, the National Organization for the Reform of Marijuana Laws filed a rescheduling petition under provisions of the Act. The government declined to initiate proceedings on the basis of their interpretation of U.S. treaty commitments. A federal Court ruled against the government and ordered them to process the petition (NORM] v. Ingersoll 497 F.2d 654 (1974)). The government continued to rely on treaty commitments in their interpretation of scheduling related issues concerning the NORML petition, leading to another lawsuit (NORML v. DEA 559 F.2d 735 (1977)). In this decision, the Court made clear that the Act requires a full scientific and medical evaluation and the fulfillment of the rescheduling process before treaty commitments can be evaluated. See Removal of cannabis from Schedule I of the Controlled Substances Act.
Cannabis leaves (as opposed to buds) are a special case. The Canadian Health Protection Branch's Cannabis Control Policy: A Discussion Paper found that, while the Single Convention requires nations to take measures against the misuse of, and illicit traffic in, cannabis buds, a ban is not required on licit production, distribution, and use of the leaves.
The Single Convention defines "cannabis" as the flowering or fruiting tops of the cannabis plant (excluding the seeds and leaves when not accompanied by the tops) from which the resin has not been extracted. (Art. 1, s-para. 1(b)) It is generally accepted that this definition permits the legalization of the leaves of the cannabis plant, provided that they are not accompanied by the flowering or fruiting tops. However, uncertainty arises by virtue of paragraph 3 of Article 28 which requires parties to the Convention to "adopt such measures as may be necessary to prevent the misuse of, and illicit traffic in, the leaves of the cannabis plant." In summary, it appears that parties are not obliged to prohibit the production, distribution and use of the leaves (since they are not drugs, as defined the Convention), although they must take necessary, although unspecified, measures to prevent their misuse and diversion to the illicit trade.