Who are the most common users of LSD?

At it's conception, LSD was primarily used to be scientists, scholars, and intellectuals to study the illicit effects it has on human cognition.

As time began to progress, others got their hands on the drug and began to experiment with its power.

In the 1950's it began being used as a treatment for alcoholics, and other wise men like Aldous Huxley turned onto the drug in 1953.

In '66 LSD becomes illegal in California. In '67 is the Summer of Love, when more people were turned onto LSD than any other.

Timothy Leary, who was later released from Harvard because of his controversial experiments with psilocybin, along with Ken Kesey, who traveled the United States in "magical bus" named Further, turned the youth onto LSD heavy in the 1960's and 70's.

To this day LSD is still widely used recreationaly by people of all kinds, primarily those in the "stoner' based counter-culture, and artists interested in expanding their perceptions.