Lysergic acid diethlyamide (LSD) more commonly known in our culture as "acid,"" belongs to a group of illicit drugs classified as hallucinogens. Hallucinogens, when ingested, can cause severe hallucinations that may last anywhere from six to twelve hours depending on purity. Hallucinations are by definition "profound distortions in a person's perceptions of reality."" The use of hallucinogens is not a new phenomenon. Psilocybin, peyote, and mescaline (derived from the peyote cactus) have been dated back thousands of years to ancient Indian religious ceremonies. An archeological dig in Mexico uncovered ancient writings, preserved by lava, that indicate the use of hallucinogens as long as four thousand years ago.
Hallucinogens, especially LSD, were prominent in the hippie culture of the 1960s and 1970s, but their popularity declined during the 1980s, giving rise to harder substances such as cocaine. In 1972 it was reported that five percent of the nation, primarily under the age of eighteen, had experimented at least once with LSD. In 1974 that number had leapt to seventeen percent, and by 1979 the numbers were up to twenty-five percent. These numbers dropped steadily as heroine and cocaine gained popularity in the 1980's, but with the 1990's came another rise in the mainstream use of LSD. In 1992 nine percent of high school seniors had tried LSD. By 1996 that number had risen to thirteen percent and in 2000 declined to eleven percent. Acceptance of the drug has clearly risen as well. In 1991 ninety percent of high school students disapproved of even a single experimentation. By 1996 that number had dropped to eighty percent. As was the case in the sixties and seventies, the primary users were young white men and women, upper to middle class, who typically chose psychotropic substances as opposed to harder drugs. Although use of LSD was primarily white, young adults, use was also found in a small percentage of young Blacks and Hispanics.