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Miguel Ángel Alcázar‐córcoles

Universidad Autónoma de Madrid

17 papers in the library · 1,530 citations · publishing 2008-2025

Papers

Personality, Psychopathology, Life Attitudes and Neuropsychological Performance among Ritual Users of Ayahuasca: A Longitudinal Study

PLoS ONE August 8, 2012 José Carlos Bouso, Débora González, Sabela Fondevila et al. 313 citations

Regular ayahuasca use over one year is associated with better psychological well-being, mental health, and cognitive performance compared to active controls in non-ayahuasca religions. Users scored higher on Reward Dependence and Self-Transcendence, lower on Harm Avoidance and Self-Directedness, and showed significantly lower psychopathology scores. They performed better on tests of attention, executive function, and working memory (Stroop test, Wisconsin Card Sorting Test, Letter-Number Sequencing). Life attitude measures indicated greater spiritual orientation, purpose in life, and psychosocial well-being. No evidence of psychological maladjustment, mental health deterioration, or cognitive impairment emerged in the ayahuasca group.

Efficacy, tolerability, and safety of serotonergic psychedelics for the management of mood, anxiety, and substance-use disorders: a systematic review of systematic reviews

Expert Review of Clinical Pharmacology August 13, 2018 Rafael G. Dos Santos, José Carlos Bouso, Miguel Ángel Alcázar‐córcoles et al. 231 citations

Serotonergic hallucinogens/psychedelics such as ayahuasca, psilocybin, and LSD show promise for reducing anxiety, depression, and substance dependence. Psilocybin and LSD reduced anxiety and depression in cancer patients and symptoms of alcohol and tobacco dependence; ayahuasca reduced depression symptoms in treatment-resistant depression. However, many studies were open-label, few were randomized controlled trials, most had small sample sizes and short duration. Single or few doses appear well tolerated, but long-term studies are lacking. New RCTs with larger samples and longer duration are needed to confirm these findings.

Assessment of addiction severity among ritual users of ayahuasca

Drug and Alcohol Dependence June 17, 2010 Josep María Fábregas, Débora González, Sabela Fondevila et al. 228 citations

Regular ritual use of ayahuasca, a psychoactive Amazonian tea containing N,N-dimethyltryptamine, does not appear to cause the psychosocial problems typical of other drugs of abuse. In two studies comparing ayahuasca users (56 jungle-based and 71 urban-based) with matched controls, users scored significantly lower on the Addiction Severity Index (ASI) Alcohol Use and Psychiatric Status subscales. Jungle-based users had a higher frequency of past illicit drug use, but this had ceased at examination except for cannabis. At one-year follow-up, abstinence from illicit drugs was maintained except for cannabis in the jungle group. ASI differences remained significant for the jungle group but not the urban group. A time-dependent worsening was observed only in the Family/Social relationships subscale in the urban group.

MDMA-Assisted Psychotherapy Using Low Doses in a Small Sample of Women with Chronic Posttraumatic Stress Disorder

Journal of Psychoactive Drugs September 1, 2008 José Carlos Bouso, Rick Doblin, Magı́ Farré et al. 206 citations

In a small, prematurely terminated study, six women with chronic posttraumatic stress disorder (PTSD) from sexual assault received low doses (50–75 mg) of MDMA during psychotherapy. The treatment was psychologically and physiologically safe for all participants. The study was originally planned for 29 subjects but closed early due to political pressures. The authors present these preliminary results and call for future research with larger samples and higher doses to better assess MDMA's safety and efficacy for PTSD.

Serotonergic psychedelics and personality: A systematic review of contemporary research

Neuroscience & Biobehavioral Reviews February 13, 2018 José Carlos Bouso, Rafael G. Dos Santos, Miguel Ángel Alcázar‐córcoles et al. 135 citations

Serotonergic psychedelics, which activate 5-HT2A receptors in the brain, can alter personality traits. A systematic review of 18 studies from 1985 to 2016 found that traits like Absorption and Self-Transcendence influence how people respond to these drugs. Users and nonusers differ in certain personality characteristics. When given in controlled settings, psychedelics may increase Openness and Self-Transcendence. Acute administration raises global brain entropy, which predicts changes in Openness. In long-term ayahuasca users, Self-Transcendence is negatively correlated with thinning of the posterior cingulate cortex. Both acute and long-term use appear to produce personality changes mediated by 5-HT2A receptors, suggesting therapeutic potential that warrants further randomized controlled trials.

Effects of ayahuasca on mental health and quality of life in naïve users: A longitudinal and cross-sectional study combination

Scientific Reports March 5, 2020 José Carlos Bouso, Daniel Jiménez‐garrido, María de Lourdes Gómez-sousa et al. 111 citations

Ayahuasca, a hallucinogenic decoction used in traditional Amazonian medicine, may have therapeutic benefits for psychiatric disorders. In a study of 40 first-time users, nearly half (45%) initially met criteria for a psychiatric disorder; after ayahuasca use, more than 80% of those showed clinical improvements that persisted at 6 months. Questionnaires indicated significant reductions in depression and psychopathology. Long-term users (n=23) had lower depression scores and higher self-transcendence and quality of life compared to first-time users. The authors suggest further controlled and observational studies are warranted to assess risks and benefits.

Ayahuasca and Public Health: Health Status, Psychosocial Well-Being, Lifestyle, and Coping Strategies in a Large Sample of Ritual Ayahuasca Users

Journal of Psychoactive Drugs February 7, 2019 Genís Oña, Maja Kohek, Tomàs Massaguer et al. 76 citations

Long-term ayahuasca use in community settings is linked to better self-reported health and healthier lifestyles. A survey of 380 regular users in Spain found that 56% reduced their prescription drug use after starting ayahuasca. Those who had used ayahuasca more than 100 times scored higher on measures of personal values. The authors conclude that respectful, controlled use of psychedelic drugs in group settings can benefit public health.

Psychological variables implied in the therapeutic effect of ayahuasca: A contextual approach

Psychiatry Research April 4, 2018 Alba Franquesa, Alberto Sainz-Cort, Sam Gandy et al. 58 citations

Ayahuasca, a psychedelic brew from Amazonia, may support mental health and boost mindfulness, but the psychological mechanisms behind its therapeutic effects are unclear. Comparing 81 ayahuasca users with 41 non-users, users scored higher on Decentering and Positive self, but not on Valued living, Life fulfillment, or measures of self in social or close relations. More experienced users (over 15 sessions) showed higher Decentering scores than less experienced ones. These findings suggest that psychological processes like Decentering could help explain ayahuasca's benefits in psychotherapy, warranting their inclusion in future studies.

Cross-Sectional Associations Between Lifetime Use of Psychedelic Drugs and Psychometric Measures During the COVID-19 Confinement: A Transcultural Study

Frontiers in Psychiatry June 16, 2021 Dóra Révész, Genís Oña, Giordano Novak Rossi et al. 42 citations

During the first strict COVID-19 lockdown (April–July 2020), people who had used psychedelic drugs regularly (more than once per six months) reported less psychological distress, less peritraumatic stress, and more social support than occasional or non-users. Regular users also scored higher on novelty-seeking and self-transcendence and lower on cooperativeness. The findings suggest that lifetime psychedelic use may be a protective factor for mental health under stressful confinement, or that pre-existing personality traits make some individuals more likely to use psychedelics. The study surveyed 2,974 English, Portuguese, and Spanish speakers online.

Assessment of the Psychotherapeutic Effects of Ritual Ayahuasca Use on Drug Dependency: A Pilot Study

November 22, 2013 Xavier Fernández, Rafael G. Dos Santos, Marta Cutchet et al. 37 citations

Ayahuasca shows promise in reducing anxiety and altering personality traits, with a study involving 80 participants revealing a significant decrease in anxiety levels for 70% of users. Participants reported enhanced emotional resilience and lower worry, suggesting ayahuasca's potential role in clinical psychology and psychiatry. The effects may stem from its influence on neurotransmitter receptors, paralleling findings in cannabis research. The temperament and character inventory indicated shifts towards more adaptive personality profiles, highlighting the therapeutic potential of psychedelics in addressing psychopathology.

Ayahuasca and Public Health II: Health Status in a Large Sample of Ayahuasca-Ceremony Participants in the Netherlands

Journal of Psychoactive Drugs May 28, 2022 Maja Kohek, Genís Oña, Michiel van Elk et al. 25 citations

Regular participation in ayahuasca ceremonies is not linked to relevant health harms. Compared to normative Dutch data, 377 participants (50.1% women, mean age 48.8 years) showed better general well-being, fewer chronic or lifestyle-related diseases, more physical activity, and a more balanced diet. During the COVID-19 pandemic, they used less alcohol. Although they used more illegal drugs than the general population, they did not report associated harms. This evidence could inform drug policymakers in developing evidence-based public policies.

The Ibogaine Experience: A Qualitative Study on the Acute Subjective Effects of Ibogaine

Anthropology of Consciousness March 1, 2020 Maja Kohek, Maurice Ohren, Paul Hornby et al. 20 citations

Ibogaine, the main alkaloid in the African shrub Tabernanthe iboga, produces a range of acute subjective effects. Interviews with twenty recent users, analyzed using grounded theory, revealed eight categories of experience: physical, sensory, visual, cognitive, auditory, adverse, anti-dependency agent, and after-effects. Ten subcategories included open and closed eye visuals (ancestors, entities, landscapes, horrific scenarios), self-psychoanalysis enhancement, empathy, love, prosocial behavior, catharsis, observer quality, ego dissolution, and spiritual states. The findings advance understanding of ibogaine's role in personal growth, prosocial behavior, therapeutic use, and anti-dependency treatments.

An analytical study of iboga alkaloids contained in Tabernanthe iboga-derived products offered by ibogaine treatment providers

Archives of Clinical Psychiatry (São Paulo) April 1, 2020 José Carlos Bouso, I. Fornís, Mireia Ventura et al. 15 citations

The purity of iboga products sold online and by treatment providers is highly variable. Analysis of 16 samples—including root bark, total alkaloids, purified total alkaloids, and ibogaine hydrochloride—found ibogaine content ranging from 0.6% to 11.2% in root bark, 8.2% to 32.9% in total alkaloid products, 73.7% in one purified sample, and 61.5% to 73.4% in ibogaine hydrochloride samples. One sample contained no iboga alkaloids. Almost all samples also contained other alkaloids and unknown substances. The variability poses risks for correct dosing and potential adverse reactions or interactions.

Detoxification from methadone using low, repeated, and increasing doses of ibogaine: A case report

Journal of Psychedelic Studies April 1, 2017 Clare Wilkins, Rafael G. Dos Santos, Jordi Solà et al. 15 citations

A woman on methadone maintenance treatment for 17 years self-treated with several low and cumulative doses of ibogaine over 6 weeks. Each dose attenuated withdrawal symptoms for hours and reduced tolerance to methadone until all withdrawal signs disappeared. No serious adverse effects occurred, and QTc measures never reached clinically significant scores. Twelve months after treatment, she was no longer on methadone maintenance. This first case report suggests that low and cumulative ibogaine doses may reduce withdrawal symptoms in patients on methadone maintenance treatment, though clinical trials are lacking.

Longitudinal and transcultural assessment of the relationship between hallucinogens, well-being, and post-traumatic growth during the COVID-19 pandemic

Scientific Reports September 11, 2023 José Carlos Bouso, Dóra Révész, Genís Oña et al. 9 citations

During the peak of the COVID-19 pandemic in April 2020, a longitudinal transcultural study surveyed English-, Spanish-, and Portuguese-speaking participants about sociodemographics, lifestyle, COVID-19 circumstances, and drug use, emphasizing hallucinogenic drugs. Users of hallucinogenic drugs reported higher psychological well-being and lower scores on psychopathology scales at baseline and follow-ups, with regular users showing even larger differences. Among those with more psychological distress, regular hallucinogen users had higher scores for post-traumatic growth. Results varied across cultural contexts, with more English-speaking regular users. The findings suggest a potential role for hallucinogens in promoting post-traumatic growth during large-scale catastrophes.

Tripping to Cope: Coping Strategies and Use of Hallucinogens during the COVID-19 Pandemic in Three Cultural Contexts

Psychoactives September 2, 2022 Genís Oña, Dóra Révész, Maja Kohek et al. 9 citations

Coping strategies are more closely linked to psychological well-being and psychopathology than to hallucinogenic drug use, according to a survey of 2,971 people from three cultural contexts followed for six months during the COVID-19 pandemic. Hallucinogen users scored higher on problem-focused engagement and disengagement coping and lower on wishful thinking than non-users. Longitudinally, most baseline coping scores were associated with psychological distress and symptom severity, while only some coping strategies were related to hallucinogen use. The results suggest an adaptive pattern of coping among hallucinogen users, but coping strategies are only marginally associated with such drug use, and other mechanisms for better pandemic adjustment should be explored.

The Ibogaine Experience Scale (IES): Development and psychometric properties of a multidimensional measure of ibogaine’s subjective effects

PLoS ONE October 13, 2025 Francisco González-espejito, Laura Esteban Rodríguez, Eduardo J. Pedrero Pérez et al.

Ibogaine, a compound from the iboga plant used in traditional Bwiti rituals, shows promise for treating opioid dependence and neurological conditions, but existing tools fail to capture its dream-like subjective effects. A new 70-item Ibogaine Experience Scale (IES) was developed from a prior qualitative study and tested with 499 participants in neuropsychiatric and substance use treatment settings. The final scale has seven factors—including narrative visions, visual changes, discomfort, cosmic visions, introspection, somatosensory sensitivity, and dissociation—explaining 53.9% of variance, with excellent statistical fit and high internal consistency. The IES offers a reliable way to measure ibogaine's multidimensional effects for research and clinical use.