Changes

Throughout the 19th century, opium was widely traded despite its ban in a few countries. In the West, it was legal and often used to derive various drugs such as morphine and heroin. It was only in 1912 that opium became banned under the International Opium Convention. Similarly, the 1920s was an era where other drugs increasingly became banned, such as marijuana, as by then crime and heavy drug use became larger problems in Western countries.<ref>For more on a recent history of opium and its banning, see Inglis, Lucy. 2018. <i>Milk of Paradise: A History of Opium</i>. London: Macmillan. </ref>

Recreational drugs have long been a part of human history. For many ancient societies, recreational use of drugs and religious worship often went together, where mind-altering drugs were seen as a way to communicate with the world of the gods and spirits. Even after converting many societies to Christianity or other monotheistic religions, recreational drugs were still widely used, although not always accepted. However, trade continued to be robust. In the late 19th century, many naturally occurring drugs began to be derived into new derivatives, such as cocaine, morphine, and heroin. In the early 20th century, many countries banned most recreational drugs, except for the relatively weaker drugs such as tobacco.