CHAPTER 3: Primary UK Drugs Legislation up to 1971

A series of Dangerous Drugs Acts that started in 1920 were primarily concerned with controlling certain plant-based drugs and the semi-synthetic drug diamorphine. This limited list had to be considerably enlarged following the United Nations (UN) Single Convention on Narcotic Drugs 1961. In the following years, misuse of amphetamine and other synthetic drugs led, in the United Kingdom, to the Drugs (Prevention of Misuse) Act 1964. The current primary legislation, the Misuse of Drugs Act 1971 (MDAct), was enacted largely to incorporate the provisions of the UN Convention on Psychotropic Substances of that year. The MDAct introduced the concept of ‘controlled drugs’. It prohibits certain activities with respect to these drugs (e.g., possession, possession with intent to supply and production). Controlled drugs are divided into Classes A, B and C. In principle, these groups represent, in decreasing order A to C, the propensity of the substances to cause social harm, but as discussed elsewhere there is almost no such clear correlation. The list of controlled drugs may be varied by a Modification or Amendment Order. The MDAct sets out maximum penalties for offences but the Sentencing Council produces guidelines for the large majority of offences which do not warrant the maximum penalty. Many reviews of the MDAct have been published in the past 50 years, particularly regarding the classification of cannabis. Few substances have been removed from control or moved to a lower classification.