Ayahuasca in adolescence: a neuropsychological assessment

This study (n=80) evaluated the neuropsychology of adolescents who used ayahuasca in a religious context, compared to a matched control group of adolescents who did not use ayahuasca. There was no significant difference between the two groups on neuropsychological measures.

Abstract

“The purpose of the study was to evaluate neuropsychologically adolescents who use ayahuasca in a religious context. A battery of neuropsychological tests was administered to adolescents who use ayahuasca. These subjects were compared to a matched control group of adolescents who did not use ayahuasca. The controls were matched with regards to sex, age, and education. The neuropsychological battery included tests of speeded attention, visual search, sequencing, psychomotor speed, verbal and visual abilities, memory, and mental flexibility. The statistical results for subjects from matched controls on neuropsychological measures were computed using independent t-tests. Overall, statistical findings suggested that there was no significant difference between the two groups on neuropsychological measures. Even though, the data overall supports that there was not a difference between ayahuasca users and matched controls on neuropsychological measures, further studies are necessary to support these findings.”

Authors: Evelyn Doering-Silveira, Enrique Lopez, Charles S. Grob, Marlene Dobkin de Rios, Luisa K. Alonso, Cristiane Tacla, Itiro Shirakawa, Paulo H. Bertolucci & Dartiu X. Da Silveira

Notes

This paper pairs well with another study that year by Da Silveria and colleagues (2011) that investigated the use of ayahuasca in adolescents. And Dobkin de Rios and colleagues (2011) that compared this group to non-ayahuasca using peers.

Summary

Ayahuasca is a hallucinogenic beverage made essentially of two Amazonian plants, although other plants are often mixed in as well. It has been used for centuries by native Indian and mestizo shamans, and was taken up by colonists during the Colonial period.

According to the laws of the UDV, adolescents are encouraged to drink ayahuasca during religious ceremonies. However, no studies have been conducted on the effects of ayahuasca use by adolescents.

A multinational research team conducted a comprehensive study with adult UDV members in 1993. The results showed that the ritualistic use of ayahuasca did not cause any injurious effects, and that the members had improved personal values, behavioral compliance, and sense of purpose.

A study of UDV adolescents’ cognitive profile is warranted, considering the growing population of people who consume ayahuasca worldwide.

Subjects and Method

Sample

Eighty-four adolescents from three cities in Brazil volunteered to participate in a study on the neuropsychological effects of ayahuasca use. The subjects were 40 adolescents from the Brazilian syncretic church UDV who had drunk ayahuasca within a ritual context at least 24 times in the last two years. Ayahuasca-nave adolescents were compared to a group of control adolescents who had never drunk ayahuasca. Both groups had similar social and economic profiles, belonged to the same community, and shared the same environmental influences.

Procedure

Subjects and controls were taken on four-day stays to farms near Brasilia and So Paulo, and on two-day stays to quiet beaches near So Paulo. Both subjects and controls were exposed to the same environmental and psychological conditions, and were kept away from tobacco, alcohol, and other drugs. They slept six to eight hours a night, and were provided with comfortable, quiet and well lit assessment rooms.

Neuropsychological Assessment

All 40 experimental adolescent subjects and 40 controls were administered a neuropsychological battery that included the Trailmaking Test, Stroop-Victoria version, Rey-Osterrieth Complex Figure Test, Conners’ Continuous Performance Test-II, and the World Health Organization/University of California at Los Angeles Auditory Verbal Learning Test.

The Trailmaking Test requires the participant to connect 25 numbers in proper order and 25 numbers and letters in alternating order.

The Digit Span and Digit Backwards subtests are used to assess psychomotor speed, and the Digit Symbol and Symbol Search subtests are used to calculate the Processing Speed Index. The Object Assembly subtest measures visual-spatial constructional abilities.

The Stroop-Victoria version is a test that measures selective attention and cognitive flexibility, and the Rey-Osterrieth Complex Figure Test is used to measure visuomotor skills, visual-spatial constructional ability, and visual memory.

The Conners’ Continuous Performance Test – Second Edition is a computerized task used to assess abilities such as sustained attention, vigilance, reaction time, and impulsivity.

The WHO/UCLA Auditory Verbal Learning Test is a verbal memory-list test that assesses verbal learning and memory.

Results

The neuropsychological tests showed no difference between ayahuasca users and controls on measures of visual search, sequencing, visual attention, psychomotor speed, and mental flexibility. Additionally, the two groups did not differ significantly on measures of verbal attention, processing speed, or memory.

Adolescent ayahuasca users and matched controls scored similarly on most trials of the WHO/UCLA Auditory Verbal Learning Test, except on two initial trials.

Discussion

This is the first study to focus on cognition of long-term ayahuasca-using adolescents. The study found no overall differences in neuropsychological performance between the group of ayahuasca-consuming adolescents and the group of adolescents who had never used the substance.

Both groups performed well and presented similar results in most neuropsychological measures, except for two trials from a verbal learning memory list test, where the ayahuasca-consuming adolescents had lower scores. However, the mean raw scores of both groups were in the average range.

Although this data overall supports the theory that ayahuasca users do not differ on neuropsychological measures, there may be subtle differences in abilities. Therefore, further studies are necessary to elucidate these findings.

In this pilot study, the authors found no evidence of injurious effects of ayahuasca on adolescents. They speculate that since the UDV adolescents use less alcohol, marijuana and other intoxicants, ayahuasca may protect the UDV adolescents from further harm.