Drugs considered addictive or dangerous in the United Kingdom are called "controlled substances" and regulated by law.
[citation needed] Until 1916 drug use was hardly controlled, and widely available opium and coca preparations commonplace.
[1]: 13–14 Between 1916 and 1928 concerns about the use of these drugs by troops on leave from the First World War and then by people associated with the London criminal society gave rise to some controls being implemented.
[1] It has been argued that the main legal innovations between 1925 and 1964 were in response to international pressures, not domestic problems.
[1] In 1991 a new phase of UK drug legislation started with an attempt to integrate health and criminal justice responses via Schedule 1A6 Probation Orders.