Psychological and cognitive effects of long-term peyote use among Native Americans
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.
Research Summary of 'Psychological and cognitive effects of long-term peyote use among Native Americans'
Introduction
Hallucinogen use is widespread and increasing, yet the long-term psychological and cognitive consequences remain poorly characterised. Previous studies have been hampered by methodological problems, chiefly that users of one hallucinogen have typically used many other illicit substances, and by potential confounders such as premorbid cognitive differences, concurrent psychiatric disorder, and recent intoxication. The peyote-containing Native American Church (NAC) offers a distinctive opportunity to study long-term exposure to a single naturally occurring hallucinogen, mescaline, because many adherents ingest peyote regularly in a religious context while largely abstaining from alcohol and other drugs. Halpern and colleagues therefore set out to assess whether long-term ceremonial peyote use is associated with residual psychological or neuropsychological deficits. The investigation compares longstanding NAC members with two Navajo comparison groups — one reporting minimal substance use and one comprising formerly alcohol-dependent but currently sober individuals — using a standard mental health inventory and a battery of neuropsychological tests focused on memory and attentional/executive functions. The aim was both to detect any peyote-related impairments and to verify that the test battery could identify deficits in a group expected to show alcohol-related impairment.
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Study Details
- Study Typeindividual
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- APA Citation
Halpern, J. H., Sherwood, A. R., Hudson, J. I., Yurgelun-Todd, D., & Pope, H. G. (2005). Psychological and cognitive effects of long-term peyote use among Native Americans. Biological Psychiatry, 58(8), 624-631. https://doi.org/10.1016/j.biopsych.2005.06.038
References (2)
Papers cited by this study that are also in Blossom
Halpern, J. H., Pope Jr, H. G. · Drug and Alcohol Dependence (1999)
Halpern, J. H., Pope Jr, H. G. · Drug and Alcohol Dependence (2003)
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