Ayahuasca’s ‘afterglow’: improved mindfulness and cognitive flexibility in ayahuasca drinkers.

Renewed interest in classical psychedelics has prompted investigation of their therapeutic potential across psychiatric disorders, particularly where current treatments fail. Ayahuasca, a plant brew that renders DMT orally active via harmala alkaloids from Banisteriopsis caapi combined with Psychotria viridis, produces a 4–6 h altered state and has been associated with improvements in depression, anxiety and substance use. Beyond pharmacology (serotonergic 5-HT2A agonism), the literature notes an ‘‘afterglow’’ period of improved mood that can last weeks to months, and the authors identify psychological mechanisms — notably mindfulness (including decentering) and cognitive flexibility — as plausible contributors to ayahuasca’s therapeutic effects. Murphy-Beiner and colleagues set out to probe whether mindfulness, decentering and cognitive flexibility change from baseline to within 24 h after an ayahuasca ceremony. The study therefore tests whether total mindfulness and decentering increase in the 24-h afterglow and whether cognitive flexibility shows concomitant improvement, while examining whether prior ayahuasca exposure moderates these short-term changes.

The study used a naturalistic, within-subject pre–post design: participants were assessed at baseline (prior to drinking) and again approximately 24 h after attending one of two secular group ayahuasca ceremonies. Recruitment was via psychedelic-interest mailing lists; eligible volunteers were aged over 18, had used or were considering using ayahuasca, and were excluded for current/prior substance dependence, current psychiatric or medical diagnoses, prescribed psychiatric medication, ongoing psychological treatment, or neurological conditions. Participants were requested to abstain from drugs and alcohol (except nicotine) for at least 24 h prior to assessments. Of 54 recruited, 48 completed both time points; mean age was 38.48 years (SD = 7.21), 54% were female, and prior lifetime ayahuasca use ranged from 0 to 130 occasions (with 12.5% psychedelic-naïve). Assessments comprised self-report questionnaires and computerised neuropsychological tasks administered in a roughly 30-minute session at each time point. Self-report instruments were the short form Five Facets Mindfulness Questionnaire (FFMQ-Short, 24 items) measuring five mindfulness facets, the Experiences Questionnaire (EQ) assessing decentering, the Cognitive Flexibility Scale (CFS, 12 items), and a study-specific drug history and dependence screen (Severity of Dependence Scale adapted for ayahuasca). Neuropsychological tests were a computerised Stroop colour–word task (reaction times and error rates for congruent vs incongruent trials) and a simplified Wisconsin Picture Card Sorting Task (WPCST) measuring set-shifting (percent correct and reaction times). Parallel/alternate versions of the Stroop and WPCST were used at the two time points to reduce practice effects. Data were analysed in SPSS 23. Total and mean scores were computed for questionnaire measures; Stroop and WPCST scores were summarised by reaction times and errors or percent correct. Given the wide range of lifetime ayahuasca use, repeated-measures ANCOVAs compared baseline and 24-h post-ayahuasca scores with prior lifetime ayahuasca use entered as a covariate. A 2 × 2 repeated-measures ANCOVA (condition congruency × time) examined Stroop reaction times, again with prior use as a covariate. A significance threshold of p = 0.05 was applied. The extracted text does not report additional details such as sample size calculations, blinding (not applicable), or biological verification of drug abstinence.

Forty-eight participants provided complete datasets at both time points. Mean scores on questionnaire measures increased from baseline to 24 h post-ceremony across total mindfulness, decentering and cognitive flexibility, and across all five FFMQ subscales. The authors report statistically significant increases for FFMQ total, CFS (cognitive flexibility self-report), and EQ (decentering). Reported statistics included F(1,46) = -8.21, η2 = 0.15 for the FFMQ total, F(1,46) = 8.25, η2 = 0.15 for the CFS, and F(1,46) = 4.15, η2 = 0.08 for the EQ. Of the five FFMQ subscales, significant increases were reported for observe (F(1,46) = 13.38, η2 = 0.24), describe (F(1,46) = 3.76, η2 = 0.08), act with awareness (F(1,46) = 7.08, η2 = 0.13), and non-reactivity (reported F(1,46) = 0.02, η2 = 0.10). The extracted text contains some inconsistencies in the reported test statistics (for example a negative F value and a very small F reported alongside a moderate η2); these may reflect extraction artefacts and the original report should be consulted for precise values. In all questionnaire analyses, there were no significant interactions between time and prior lifetime ayahuasca use (all p's > 0.05), indicating the pre–post changes did not differ by prior exposure. On the WPCST, participants showed a significantly higher percentage of correct responses 24 h after ayahuasca relative to baseline, with no significant change in reaction times; the authors interpret this as improved accuracy without slowing. For the Stroop task, a robust main effect of congruency was observed for reaction time (F(1,46) = 58.28, η2 = 0.56) and number of errors (F(1,46) = 20.42, η2 = 0.31), reflecting the expected interference effect. There was no significant main effect of time on Stroop reaction time or errors, but a significant time × condition interaction was reported for number of errors (F(1,46) = 4.11), indicating a relative reduction in errors on the incongruent (interference) condition post-ayahuasca; reaction time showed no such interaction. As with the questionnaires, no significant covariate interactions with prior ayahuasca use were found for the neuropsychological task outcomes (all p's > 0.05).

Murphy-Beiner and colleagues interpret their findings as evidence that a single ayahuasca ceremony is associated with short-term increases in mindfulness (total FFMQ scores and four of five facets), decentering, and cognitive flexibility (self-report CFS and objective WPCST performance) within 24 h. They note that these changes occurred irrespective of prior ayahuasca exposure, suggesting that both experienced and less experienced or naïve users may show similar short-term psychological gains in the afterglow period. The authors position these results alongside earlier studies that reported increased mindfulness 24 h after ayahuasca and link the cognitive findings to neurobiological work showing ayahuasca-related modulation of networks implicated in flexibility (default mode, central executive and salience networks) and structural differences in regions such as the anterior cingulate cortex. Differences across studies in which FFMQ facets change are acknowledged; the authors suggest that sample characteristics, differing questionnaire versions (short vs full FFMQ), and unmeasured variables such as prior meditation experience may account for inconsistencies. They argue that the concurrent improvement in decentering and emotional-acceptance facets supports the idea that ayahuasca can influence both attentional and acceptance components of mindfulness. Regarding cognition, the authors contrast their WPCST/WCFS findings with prior mixed reports using divergent- and convergent-thinking tasks, noting that different tasks tap distinct aspects of flexibility or creativity. Key limitations reported by the authors include susceptibility of the WCST and Stroop to learning/practice effects despite use of parallel versions, reliance on self-reported drug histories without biological verification, unknown and unrecorded doses of ayahuasca, absence of acute-phase measures (only pre and 24-h post were collected), and lack of a control group. They further note the sample was self-selected and largely experienced, limiting generalisability to clinical or psychedelic-naïve populations, although the present sample was less experienced than some prior work. The authors conclude that mindfulness and cognitive flexibility are plausible psychological mechanisms contributing to ayahuasca's therapeutic potential and that understanding the afterglow period is important for developing ayahuasca-assisted treatments, while calling for controlled and longer-term studies to clarify dose, durability and causal relationships.