A controlled substance is a drug or chemical whose manufacture, possession or distribution is highly regulated by the government and subject to legislative control.
Controlled drugs include the following: illegal drugs, prescription medications, and chemicals considered precursors to the production of illegal drugs. These are all deemed to cause harm to an individual, if they are not properly used.
Manufacturing and distribution of controlled drugs is closely monitored by the United Nations (UN) on a global basis. The construction of an international legal framework for controlled drugs has gone through several stages of development since the 1920 prohibition of alcohol in the US.
In 1961, the UN Single Convention on Narcotic Drugs was established as a universal system to limit the cultivation, production, distribution, trade use and possession of narcotic substances strictly to medical and scientific purposes, with special attention to substances produced from plants.
A decade later, in 1971, the Convention introduced prescription requirements for controlled drugs, as well as a regulatory framework to include the inspection of manufacturers (exporters, importers, wholesale and retail distributers, and medical/ scientific institutions). In a groundbreaking move, the Convention also created four schedules for controlled psychotropic substances, mainly evaluated based on the risk of creating drug dependency (2).