National Geographic sent a reporter to take part in an ancient Peruvian shamanic ritual where the hallucinogenic plant ayahuasca is used.
The article describes the reporter’s account of what sounds like a profound and terrifying experience, and discusses the culture, traditions and interest from Western science that ayahuasca has inspired.
The taking of ayahuasca has been associated with a long list of documented cures: the disappearance of everything from metastasized colorectal cancer to cocaine addiction, even after just a ceremony or two. It’s thought to be nonaddictive and safe to ingest. Yet Western scientists have all but ignored it for decades, reluctant to risk their careers by researching a substance containing the outlawed DMT. Only in the past decade, and then only by a handful of researchers, has ayahuasca begun to be studied.
At the vanguard of this research is Charles Grob, M.D., a professor of psychiatry and pediatrics at UCLA’s School of Medicine. In 1993 Dr. Grob launched the Hoasca Project, the first in-depth study of the physical and psychological effects of ayahuasca on humans. His team went to Brazil, where the plant mixture can be taken legally, to study members of a native church, the Uni√£o do Vegetal (UDV), who use ayahuasca as a sacrament, and compared them to a control group that had never ingested the substance. The studies found that all the ayahuasca-using UDV members had experienced remission without recurrence of their addictions, depression, or anxiety disorders. In addition, blood samples revealed a startling discovery: Ayahuasca seems to give users a greater sensitivity to serotonin‚Äîone of the mood-regulating chemicals produced by the body‚Äîby increasing the number of serotonin receptors on nerve cells.
Link to article ‘Peru: Hell and Back’ with video clip (via MeFi)
Link to excellent Wikipedia page on ayahuasca.
Mind Hacks 
This article is quite interesting. These kinds of profound transformative experiences have long been associated with psychological healing. After psychology was emerging from its late 19th century “spiritualism” phase (prompted by the desire of the American populace wanting to contact their ancestors killed during the Civil War), William James wrote extensively on it, and it formed the basis for his lectures in Edinburgh on The Varieties of Religious Experience. He describes these kinds of transcendant experiences in his chapter on “Conversions.” We are only now, after the behaviorism, cognitive science, and neuroscience dominance of the field, coming back to study consciousness (despite James’ pleadings that the new science of psychology should not ignore consciousness). The wheel turns ’round.