Steve Beyer
We have talked before about the Grob, McKenna, Callaway, et al., psychiatric study on the long-term effects of drinking ayahuasca in the ceremonies of the União do Vegetal church. I noted that the study had not clearly disentangled any bias that might have resulted from the fact that the ayahuasca drinkers — but not controls — had been preselected for their orderly churchgoing habits. Here is a study that may shed some light on that question.