Short answers, pulled from the story.
It is estimated that about 5% of people worldwide aged 15 to 65 have used a controlled drug at least once, a figure representing between 158 million and 351 million individuals. This estimate excludes widely used legal substances such as caffeine, alcohol, and nicotine.
Recreational drugs are commonly divided into three categories: depressants, which slow down the central nervous system; stimulants, which speed it up; and hallucinogens, which induce perceptual distortions. Alcohol is the most widely used depressant, caffeine is described as the world's most widely consumed psychoactive drug, and LSD and psilocybin are among the best-known hallucinogens.
LSD was banned in the United States in October 1968 by President Lyndon B. Johnson. It had been first synthesized in 1938 by Albert Hofmann, though Hofmann did not notice its psychedelic effects until 1943.
The Controlled Substances Act of 1970 classified marijuana as a Schedule I drug alongside heroin and LSD, designating it as having the highest abuse potential and no accepted medical use. This classification followed a period in which arrests for marijuana possession in the United States had increased by 98% between 1966 and 1968, according to an FBI report.
Harm reduction is a policy approach that emphasizes minimizing the dangers of drug use rather than eliminating use entirely. It began in the 1970s counterculture and was popularized as a formal framework in the late 1980s. Core principles include not using drugs while driving or operating machinery, and advocates argue that legalized drug production and distribution would reduce overdose risks caused by adulterated or impure street drugs.
A 2019 systematic review and meta-analysis by Murrie et al. found that the transition rate from opioid-induced psychosis to schizophrenia was 12%, from alcohol-induced psychosis 10%, and from sedative-induced psychosis 9%. For hallucinogen-induced psychosis, the estimated transition rate to schizophrenia is 26%, while a separate 2019 meta-analysis found that 22% of people with amphetamine-induced psychosis later received a schizophrenia diagnosis.