Many researchers have explored the etiology of recreational drug use. In 2015, it was estimated that about 5% of people worldwide aged 15 to 65 (158 million to 351 million) had used controlled drugs at least once. What controlled substances are considered generally unlawful to possess varies by country, but usually includes methamphetamine, heroin, cocaine, LSD, psilocybin mushrooms, MDMA, Lean, and club drugs. Recreational drugs include alcohol, commonly found in beer, wine, and distilled spirits cannabis and hashish (with legality of possession varying inter/intra-nationally) nicotine, commonly found in tobacco caffeine, commonly found in coffee, tea, soft drinks, prescription drugs the controlled substances listed as controlled drugs in the Single Convention on Narcotic Drugs (1961) and the Convention on Psychotropic Substances (1971) of the United Nations and cocoa, commonly found in chocolate. Many people also use prescribed and controlled depressants such as opioids, along with opiates, and benzodiazepines. However, heavy use of some drugs is socially stigmatized.

In popular practice, recreational drug use generally is a tolerated social behaviour, rather than perceived as the medical condition of self-medication. Generally, recreational drugs are divided into three categories: depressants (drugs that induce a feeling of relaxation and calmness) stimulants (drugs that induce a sense of energy and alertness) and hallucinogens (drugs that induce perceptual distortions such as hallucination). When a psychoactive drug enters the user's body, it induces an intoxicating effect. Recreational drug use is the use of a psychoactive drug to induce an altered state of consciousness either for pleasure or for some other casual purpose or pastime by modifying the perceptions, feelings, and emotions of the user.

Drugs in fallout 4