Beware psychedelic South American teas.

From an interesting entry on travel site Gadling. (Thanks JenK!)

Fast-forward two years: I'm sitting in a large dug-out canoe in the Ecuadorian jungle with three German guys and our guide, Marcelo. We're in the middle of a week-long trip to the Cuyabeno Nature Reserve, an Amazonian rainforest located in the northeastern part of Ecuador.

We're on our way to visit a shaman (medicine man) and his family, when I turn to Marcelo and, remembering my paper from college, ask whether the religious groups around here ever use a tea called ayahuasca in their services. Marcelo pauses, looks at me with a half-smile, and says, "You want to try ayahuasca?"

[...] "That was the worst night of my life. I will, as always, blame someone else. Our guide Marcelo apparently thought we'd be okay without fasting before the ayahuasca. Turns out, all the food in my stomach absorbed the nasty tea, and instead of puking twenty minutes in-- like we were supposed to-- and returning to Earth three hours later, I writhed in agony for nine hours.... "It shouldn't go unmentioned, however, that I did manage to enjoy some of the positive effects of the ayahuasca: colorful open-eyed hallucinations, extreme visual mind-f***s, and an all-together giddy demeanor. But then, somehow, things began to turn south, or perhaps a better way to put it is that things turned into hell on Earth. It's difficult to describe with any precision, but I'll give it a go anyway. I began losing track of who I was; I couldn't form abstract thoughts; I turned into an animal looking only for survival...

"I couldn't wake up from the nightmare, couldn't return to anything resembling a functional human being. I had roughly a hundred false awakenings. They lasted forever... Never in my life have I felt so utterly alone, so helpless, so out of control, so insane. I remember asking a biologist from West Texas, as I was finally coming out of the daze, to tell me his life story so that I could latch on to someone else's coherent thoughts. So I could remember where I was, what I was doing.

"The most frightening part was not knowing if I'd ever return to normal. I imagined myself-- or rather, I would have imagined myself if I remembered how to imagine-- like Jack Nicholson at the end of Cuckoo's Nest when they wheel him in: the lights are on but nobody's home. It entered my mind that maybe I was dead, and that if I wasn't, maybe I wanted to be."