Peruvians were chewing coca leaves some 8,000 years ago
Coffee, a glass of wine, an antidepressant and a banned hallucinogen share one trait: they change how the brain works. Humans have sought such substances for at least 10,000 years, and some researchers argue the urge to shift consciousness is as basic as hunger, visible even in children who love to spin until dizzy.
A psychoactive drug is any chemical that changes psychological functioning by acting on the central nervous system, usually by boosting or damping neurotransmitter activity. That can alter mood, perception, thinking and behaviour, and over time the brain may adapt through tolerance or sensitisation. The effect depends not only on the substance but also on the setting and the person taking it.
Pharmacologists sort these substances by effect. Anxiolytics such as the benzodiazepines Xanax and Valium ease anxiety; entactogens heighten feelings of empathy and closeness; stimulants raise alertness and are prescribed for ADHD and narcolepsy; depressants slow the nervous system; hallucinogens reshape perception and emotion. The word psychotropic sometimes means the same thing, though it can refer narrowly to psychiatric medicines or to substances with high abuse potential. Designer drugs, or novel psychoactive substances, are engineered to mimic banned drugs while slipping past existing laws.
The history is long and cross-cultural. Archaeology points to plant-based use at least 10,000 years ago and documented cultural use around 5,000 years ago; many animals seek out intoxicants too, and some legends credit them with teaching humans. In 1857 Fitz Hugh Ludlow's The Hasheesh Eater described drug-seeking in almost spiritual terms, as a longing to glimpse a higher reality. Today the most widely used examples are legal: caffeine, alcohol and nicotine.
Law has swung back and forth. The 20th century brought widespread criminalisation, including 13 years of alcohol Prohibition in the United States, and treaties such as the 1961 Single Convention on Narcotic Drugs. More recently some governments have moved toward harm reduction; Portugal decriminalised drug use with the aim of limiting health damage. Globally, the most common use disorders involve alcohol, cannabis and opioids. One US study covering 1988 to 2019 found that each extra day of tropical cyclone exposure was linked to a 3.84 percent rise in drug-related death rates that month.
Source: Psychoactive drug
