Psychological and cognitive effects of long-term peyote use among Native Americans
Halpern, J. H., Hudson, J. I., Pope Jr, H. G., Sherwood, A. R., Yurgelun-Todd, D.
This correlational study (n=176) investigated the long-term residual psychological and cognitive effects of peyote use amongst native American Church members, compared between regular users (n=61), minimal users (n=79), and members with a history of alcohol dependence (n=36). Only members with prior alcohol dependence showed neuropsychological deficits, but there was no link between psychological or cognitive deficits linked to peyote use.
Abstract
Background: Hallucinogens are widely used, both by drug abusers and by peoples of traditional cultures who ingest these substances for religious or healing purposes. However, the long-term residual psychological and cognitive effects of hallucinogens remain poorly understood.Methods: We recruited three groups of Navajo Native Americans, age 18-45: 1) 61 Native American Church members who regularly ingested peyote, a hallucinogen-containing cactus; 2) 36 individuals with past alcohol dependence, but currently sober at least 2 months; and 3) 79 individuals reporting minimal use of peyote, alcohol, or other substances. We administered a screening interview, the Rand Mental Health Inventory (RMHI), and ten standard neuropsychological tests of memory and attentional/executive functions.Results: Compared to Navajos with minimal substance use, the peyote group showed no significant deficits on the RMHI or any neuropsychological measures, whereas the former alcoholic group showed significant deficits (p < .05) on every scale of the RMHI and on two neuropsychological measures. Within the peyote group, total lifetime peyote use was not significantly associated with neuropsychological performance.Conclusions: We found no evidence of psychological or cognitive deficits among Native Americans using peyote regularly in a religious setting. It should be recognized, however, that these findings may not generalize to illicit hallucinogen users.