Traditional Sources

• Toads, fungi, cacti and certain other plants have been the source of hallucinogens historically prior to the development of synthetic drugs.
  
  

Synthetic Drugs

• In the early 20th century, western scientists began to study some of the traditional hallucinogenic substances. In 1938, Albert Hoffman of Switzerland discovered lysergic acid diethylamide (LSD).
  
  

Modern Uses

• In the 1950s, psychiatrists used LSD to cure many conditions including schizophrenia, alcoholism and deviant behavior. From the early 1960s there was a boom in usage by the hippie counterculture, with LSD being the most widespread and popular.
  
  

Criminalization

• Possession of LSD was made illegal in the United States in 1967 for fear that it was becoming too mainstream. Criminalization and cultural changes led to reduced use for the next two decades.
  
  

Ecstasy

• During the 1990s, LSD made something of a comeback as Ecstasy, a new "party" drug. Ecstasy also became very popular in Europe, later in the United States. The resurgence lasted for one decade and then a new decline set in.