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

Ayahuasca is an Amazonian decoction combining Banisteriopsis caapi, which provides harmala alkaloids that act as reversible MAO inhibitors, with plants such as Psychotria viridis that supply DMT. Franquesa and colleagues note that the brew produces an altered, introspective state featuring autobiographical imagery, emotional material and transpersonal experiences, and that anecdotal and some empirical evidence point to therapeutic benefits for conditions including addiction and treatment‑resistant depression, as well as improvements in creativity, neuropsychological function and certain personality domains. Although safety concerns are discussed in the literature, the authors report that studies comparing ritual ayahuasca users with non‑users generally have not found worse psychopathological or neuropsychological outcomes among users. The investigators identify a gap in the literature: the psychological process variables that might explain ayahuasca's putative therapeutic effects have not been well characterised. They propose that constructs emphasised in contextual psychotherapies—especially Decentering (the capacity to observe thoughts and feelings as transient mental events rather than identifying with them), values‑based living, and aspects of self‑experience such as public control and a ‘‘positive self’’—could mediate outcomes. The study therefore aims to compare ayahuasca users and non‑users on measures of Decentering, Values and experience‑of‑self, and to explore whether these process measures differ by frequency of ayahuasca use.

This cross‑sectional, naturalistic study recruited 122 adults: 81 people with prior ayahuasca experience and 41 who had never used it. Ayahuasca users were drawn from local associations, collectives and Santo Daime church groups in Catalonia; all reported using ayahuasca in ritualised group settings (ceremonies usually guided by a facilitator, often a psychologist). The authors report that none of the participants used ayahuasca in purely recreational settings. The study received ethical approval from the Unió Catalana d'Hospitals Ethics Committee and all participants provided written informed consent. Sociodemographic and descriptive data included age, gender, education, ayahuasca and other drug history, and psychiatric medication. Psychopathology was screened using the Brief Symptom Inventory‑18 (BSI‑18) for global distress and subscales of somatisation, depression and anxiety, and the psychoticism scale of the SA‑45. Process‑oriented instruments were: the Experiences Questionnaire (EQ) for Decentering and rumination (11 items), the Engaged Living Scale (ELS) with subscales for Valued Living and Life Fulfilment (16 items total), and the Experiencing of Self Scale (EOSS; 37 items) assessing public control of the self in intimate and casual relationships and general self, plus a Positive self factor reflecting creativity and spontaneity. Spanish validated versions of these scales were used. Statistical analyses compared ayahuasca users and non‑users using chi‑square tests for categorical variables and independent‑samples t‑tests for continuous variables. To examine dose/experience effects, the ayahuasca group was split into AYA 1–15 (1–14 experiences) and AYA >15 (more than 15 experiences), yielding three groups (non‑users, AYA 1–15, AYA >15). Group comparisons on sociodemographics used chi‑square and ANOVA with Bonferroni post hoc correction; process variables were compared with ANOVA (Bonferroni). Correlations between the number of ayahuasca experiences and the process measures were also computed.

The sample comprised 81 ayahuasca users and 41 non‑users. No between‑group differences emerged for age, gender or education when users and non‑users were compared as whole groups. Psychopathology indices (BSI‑18 subscales and SA‑45 psychoticism) did not differ between users and non‑users. On the primary process measures, ayahuasca users scored higher than non‑users on Decentering (EQ) and on the Positive self factor of the EOSS. There were no overall group differences for Valued Living, Life Fulfilment, Self in general, Self in social relations or Self in close relations. When the ayahuasca users were stratified by experience, the groups differed in mean age: the AYA >15 group was older on average than the other groups. Substance‑use comparisons across the three groups identified a higher recent MDMA consumption in the AYA 1–15 group (χ2 = 8.80; p = 0.012). Comparing the three experience groups, Decentering scores were significantly higher in the AYA >15 group than both non‑users and AYA 1–15. AYA 1–15 scored lower than AYA >15 on Valued Living and higher than AYA >15 on Self in social relations. The AYA 1–15 group also scored higher than both non‑users and AYA >15 on Self in general. Correlation analyses between the absolute number of ayahuasca experiences and Decentering, Valued Living, Life Fulfilment, Self in general, Self in social relations, Self in close relations and Positive self were non‑significant.

Franquesa and colleagues interpret their findings as preliminary support for the idea that ayahuasca use is associated with psychological process changes relevant to psychotherapy, particularly Decentering and aspects of a Positive self (creativity and spontaneity). They highlight that the lack of group differences on standard psychopathology measures aligns with prior naturalistic studies showing ritual ayahuasca users do not typically display elevated psychopathology compared with controls. The observation that higher Decentering appeared mainly in those with more than 15 ayahuasca experiences is noted as consistent with limited prior evidence of post‑session increases in decentering, and the authors situate this capacity within mechanisms proposed for mindfulness‑based and cognitive therapies as protective against relapse. The authors discuss Values findings cautiously: while no overall difference was seen for Valued Living or Life Fulfilment between users and non‑users, more experienced users scored higher on Valued Living than less experienced users, which the investigators link to reports that psychedelic experiences can shift life meaning and purpose. Regarding self‑experience, only the Positive self index differed between users and non‑users; changes in other public‑control dimensions were inconsistent, with less experienced users showing some indicators of greater dependence on others. The authors speculate that lower Valued Living and greater public control among less experienced users might reflect pre‑existing struggles that motivated ayahuasca use or early crisis processes during therapeutic work, whereas sustained use and integration could lead to longer‑term increases in decentering and positive self‑functioning. Key limitations are emphasised: the cross‑sectional, retrospective design and exclusive reliance on self‑report instruments prevent causal inference and make it impossible to separate pharmacological effects from ritual/contextual influences. The authors acknowledge missing information on dosage, acute subjective effects and the broader context of each session. They also note potential confounding from differences in recent MDMA use and the possibility that observed differences reflect pre‑existing personality traits rather than ayahuasca exposure. Given these constraints, Franquesa and colleagues call for prospective, controlled studies with richer contextual and behavioural measures and for attention to set, setting and post‑session integration processes to better understand how ayahuasca may produce therapeutic change.