Psilocybin, the active ingredient of "magic mushrooms," expands the mind. After a thousand years of use, that's now scientifically official.

The chemical promoted a mystical experience in two-thirds of people who took it for the first time, according to a new study. One-third rated a session with psilocybin as the "single most spiritually significant" experience of their lives. Another third put it in the top five.

The study, published online today in the journal Psychopharmacology, is the first randomized, controlled trial of a substance used for centuries in Mexico and Central America to produce mystical insights.

• PDF of Griffiths Psilocybin Study Results
• Official Press Release of Study from Johns Hopkins