Before finishing the historical consideration of the subject, one should pay attention to the interesting and long-standing relationship between the use of psychoactive substances as drugs (this is discussed in detail in Chapter 5) and their use for other purposes. Many of these drugs were once used for medicinal purposes. Medicine did not immediately become such a science as we know it now. Even in our century, various folk remedies and so-called “patented drugs” were widespread. Perhaps the best example is the opiates (opium and morphine), which throughout the 19th century were used in the treatment of various diseases – rheumatism, pain, fever, delirium tremens, colds, etc. Opiates served as anesthesia during surgical operations. Doctors widely used opiates and often prescribed them to patients, while very poorly imagining how they affect the body. They only knew that opiates relieve pain and other, mostly incomprehensible, symptoms. Unfortunately, such widespread use led to a significant increase in the number of people falling into physical dependence on these substances. The fact that drugs are addictive was clearly realized only in the 1870s.

There are many more examples. Chloroform and ether were developed as anesthetic drugs, but they also did not pass use for inappropriate purposes: it was in the middle of the last century. In the history of cocaine, there was a period when it was used to treat depression and relieve pain. He was even used as a cure for opium addiction! In the second half of the 19th century, doctors found many uses for marijuana, including the treatment of insomnia and nervous disorders. However, their list was smaller than for opiates. In the twentieth century, we witnessed the emergence of synthetic amphetamine stimulants, and some of them were available for a long time without a prescription.

It is important to understand that in medicine (whether popular or modern), the use of psychoactive substances as medicines and their use for non-medical purposes will always be closely related. In the past, such substances often came into medicine from religious ceremonies and traditional medicine practices. Nowadays, a situation where a substance developed as a drug replenishes the ranks of drugs is common. In any case, it will not be possible to separate medicine and drugs.