THE STUDY: Volunteers who took psilocybin, an illegal drug made from mushrooms, reported profound mystical experiences that altered their attitudes and behavior for weeks.

THE CONFIRMATION: The drug has been used for centuries in religious practices, but the new work demonstrates its effects more clearly than before.

THE PAYOFF: Psilocybin may prove useful in treating drug addicts or terminally ill patients with depression. It may also enable the study or what happens in the brain during intense spiritual experiences.