The use of hallucinogens in the United States appears to be on the rise.

Hallucinogen use first became widespread in the 1960s, especially on college campuses. Promoted by Timothy Leary, a psychology instructor at Harvard, LSD and other drugs were hailed as the source of psychic awakening, happiness, fulfillment, creativity, and other good things. As the decade passed, it became clear that bliss could not be attained simply by dropping acid, and many people experienced negative effects resulting from habitual drug use. The use of hallucinogens decreased and reached its lowest level in the mid-1980s.

Since the beginning of the 1990s, however, hallucinogen use has steadily increased. The Drug Enforcement Agency (DEA) states on its website, "There has been a growing interest among young adults and adolescents to re-discover ethnobotanical plants" that can induce hallucinations or "mystical" experiences. The number of new hallucinogen...