A category of addictive drugs that reduce the perception of pain and induce euphoria.

A narcotic is a depressant that produces a stuporous state in the person who takes it. Narcotics, while often inducing a state of euphoria or feeling of extreme well being, are powerfully addictive. The body quickly builds a tolerance to narcotics, so that greater doses are required to achieve the same effect. Because of their addictive qualities, most countries have strict laws regarding the production and distribution of narcotics.

Historically, the term narcotic was used to refer to the drugs known as opiates. Opium, morphine, codeine, and heroin are the most important opiate alkaloids—compounds extracted from the milky latex contained in the unripe seedpods of the opium poppy. Opium, the first of the opiates to be widely used, was a common folk medicine for centuries, often leading to addiction for the...