During the last twenty years, analysis into psychedelic and cannabinoid-based therapies for psychological well being issues has quickly expanded.
Classical psychedelics (LSD, psilocybin and DMT) are being investigated as therapies for melancholy and anxiousness (Wickham, 2024) and cannabis-based medicines are being more and more explored for a variety of indications from insomnia to tic issues, and autism (De Bode, 2024).
Because the scientific neighborhood grapples with a quickly evolving proof base, contrasting approaches to regulatory approval and authorities coverage have already begun to form public entry. In 2023, Australia turned the primary nation to licence psilocybin as a remedy for melancholy inside psychiatric settings (Henriques, 2023), In the meantime within the UK, cannabis-based medicinal merchandise at the moment are be prescribed by specialist medical doctors, though use is essentially confined inside the non-public sector.
As these beforehand prohibited substances turn out to be extra utilised, acquainted questions resurface: what are their long-term results on the mind and psychological well being?
A brand new examine by Bouso et al (2026) sought to discover this by investigating if long-term customers of hashish and ayahuasca (a natural brew containing DMT) differed to non-users with respect to character, cognition and psychological well being.
Strategies
This was a cross-sectional examine primarily based in Spain evaluating measures of character, cognition, and psychological well being between ayahuasca, hashish, and non-regular substance customers.
Ayahuasca customers have been members of the Spanish Santo Daime Church, a spiritual group the place ayahuasca is consumed ceremonially, whereas hashish customers have been members of Catalan cannabis-activist teams.
Contributors attended a screening go to, then a examine go to the place a battery of neuropsychological, character and psychological well being scales have been accomplished. To be included contributors wanted to be abstinent from ayahuasca for 10 days, and hashish for 30 days previous to the examine go to, and have a damaging urine drug check on the day.
To determine how character, cognition and psychological well being differed throughout the teams, researchers used multinomial linear regression (MLR). To forestall overloading the mannequin with predictors, solely variables that exhibited a near-significant (p<0.1) relationship with person group have been included.
Variables have been entered into the MLR in phases (stepwise method). At every stage non-significant predictors have been eliminated. Mannequin match was assessed utilizing the Akaike Info Criterion (AIC) metric. A decrease AIC signifies a greater mannequin match with fewer pointless predictors.
Outcomes
The ultimate pattern comprised 219 contributors: 69 ayahuasca customers, 56 hashish customers and 94 non-regular substance customers. Lifetime publicity indicated long-term use with ayahuasca customers reporting a imply use of practically 190 instances and hashish customers over 33,000 instances.
The ultimate mannequin had an adjusted R2 worth of 28% that means that the included predictors defined 28% of the variability in group membership.
Stage 1: sociodemographic, psychiatric historical past and IQ
Hashish customers have been youthful, extra prone to be male, have decrease instructional attainment and better fluid intelligence than non-user controls. Ayahuasca customers have been extra prone to have a earlier melancholy or anxiousness analysis than non-users. When these variables have been added into the MLR, solely age, intercourse and former melancholy analysis remained statistically important predictors of group membership. This preliminary mannequin defined 8% of variability in group membership.
Stage 2: neuropsychological exams
There have been no statistically important variations throughout person teams on measures of govt functioning, working reminiscence, selective consideration, cognitive flexibility or determination making. These measures have been due to this fact not included within the ultimate mannequin.
Stage 3: psychological well being signs
Hashish customers demonstrated statistically considerably decrease obsessive-compulsive and psychoticism scores than non-users. Nevertheless, none of those associations remained important as soon as entered into the MLR and have been due to this fact not retained, suggesting the presence of psychological well being signs was much less vital for distinguishing teams.
Stage 4: schizotypal traits
Ayahuasca customers reported extra uncommon experiences than wholesome controls, whereas hashish customers demonstrated higher impulsive non-conformity and introvertive anhedonia. Inclusion of those variables elevated the proportion of variance in group membership defined to 14.1%.
Stage 5: temperament and character dimensions
Ayahuasca customers demonstrated statistically considerably larger self-transcendence, and decrease persistence and hurt avoidance to wholesome controls. Hashish customers, alternatively, demonstrated higher novelty looking for than wholesome controls. These variables remained important within the MLR and inclusion elevated the defined variance to roughly 28%. This implies that variations in temperament and character dimensions accounted for probably the most variation in group membership.
Conclusions
Bouso et al. (2026) in contrast long-term ayahuasca customers, hashish customers and non-users on measures of cognition, psychological well being and character. Whereas person teams had substantial lifetime substance use, no variations have been recognized in exams of govt functioning, working reminiscence, consideration or decision-making.
Persona measures that assessed temperament and character dimensions defined the biggest variation in group membership. Ayahuasca customers demonstrated larger self-transcendence and decrease persistence and harm-avoidance to non-users, whereas hashish customers demonstrated higher novelty looking for.
Strengths and limitations
Learning the long-term results of a drug is difficult. Customers typically devour a number of substances, differ in vital sociodemographic traits, and will have co-morbid psychological well being circumstances. In an try to minimise the affect of those confounding variables, Bouso et al. (2026) adopted a novel naturalistic design, recruiting contributors from established social teams the place ayahuasca (Santo Daime church) or hashish (hashish activist networks) use was an built-in cultural observe.
Whereas this method strengthens the examine via improved ecological validity by capturing functioning people with real-world publicity relatively than skewed treatment-seeking populations, it possible launched choice bias. Non secular organisations and activist networks might appeal to people with distinct beliefs, values and attitudes unbiased of substance use. Consequently, though the noticed character profiles have been in keeping with earlier analysis (larger self-transcendence in ayahuasca customers and novelty looking for in hashish customers), it’s unclear whether or not these variations mirror neighborhood membership or the long-term results of the drug. With out potential evaluation, the path of causality can’t be inferred. The distinctive recruitment technique may restrict the generalisability of the findings to individuals who use these substances outdoors these communities.
Whereas the distinct recruitment technique aimed to scale back the incidence of polysubstance use, contributors additionally reported utilizing different substances. This isn’t an uncommon discovering in drug analysis. Right here, greater than 40% of hashish customers reported MDMA or cocaine use within the earlier month and 42% of ayahuasca customers reporting hashish use within the final month. Though the frequency of use of those substances was not reported, these ranges of polysubstance use usually are not insignificant and will have contributed to the findings. Moreover, whereas the recruitment method was supposed to enhance matching teams on age, intercourse, training and psychological well being historical past, variations between teams remained, with age, intercourse and former melancholy being retained within the ultimate mannequin.
Regardless of these limitations, the authors must be recommended for his or her efforts to minimise acute drug results by requiring each an abstinence interval and a damaging drug check earlier than participation. That is notably vital when investigating cognition, as earlier meta-analyses recommend that many cognitive deficits related to hashish use diminish following extended abstinence (Schreiner & Dunn, 2012). That stated, the 10-day abstinence interval for ayahuasca customers was supposed to scale back acute results, nonetheless it stays unclear whether or not subacute modifications in neuroplasticity might nonetheless have influenced cognition or psychological well being outcomes (De Vos et al., 2021).
Moreover, the authors used a complete evaluation battery incorporating a number of validated exams assessing a wide range of cognitive domains, alongside questionnaires measuring psychopathology and character. This allowed the authors to check a number of competing explanations for group variations inside a single analytical framework.
Implications for observe
In 1987, anti-drug campaigners in the US ran an commercial evaluating the results of medicine on the mind to frying an egg.
Whereas Bouso et al.’s examine challenges this simplistic message, discovering no important variations throughout a variety of neuropsychological exams, the outcomes require cautious interpretation. Sure, ayahuasca and hashish customers on this examine didn’t differ from controls on measures of working reminiscence, govt functioning, selective consideration or cognitive flexibility. Nevertheless, this doesn’t essentially imply these substances don’t have any long-term cognitive results.
On the one hand, Bouso et al.’s cognitive findings align with earlier hashish analysis suggesting that cognitive deficits might diminish following extended abstinence (Schreiner & Dunn, 2012). Nevertheless, earlier opinions point out that cannabis-related cognitive outcomes could also be affected by age of onset, frequency of use, THC dose and co-occurring psychological well being difficulties (Kroon et al., 2021). As this was a cross-sectional examine recruiting socially built-in customers, it’s attainable that people who skilled dangerous cognitive or psychological well being penalties arising from hashish have been much less prone to be recruited as a result of they’d already stopped utilizing hashish or have been now not a part of these socially built-in communities. Subsequently, the examine’s pattern might characterize a subgroup of customers who can tolerate these substances or who had larger baseline cognitive functioning, maybe mirrored by the excessive fluid intelligence noticed amongst hashish customers.
Whereas the restrictions of the character findings have already been mentioned, the variations noticed between ayahuasca and hashish customers are notably fascinating provided that particular person variations might affect one’s response to psychoactive substances. It is a central assumption in psychedelic analysis, the place “set” (a person’s mindset, expectations and character) and “setting” (the social, cultural and bodily atmosphere by which a substance is taken) have been hypothesised to affect the acute drug experiences – though this has largely lacked empirical testing (Carhart-Harris et al., 2018). Subsequently, when character dimensions comparable to self-transcendence are larger in ayahuasca customers this may occasionally not merely characterize an impact of the drug or the kind of particular person drawn to ayahuasca. As an alternative, it might mirror an interplay between character, the cultural context of use, and the drug’s pharmacological results. This interplay might have vital medical implications as psychedelic- or cannabis-based therapies enter medical observe, with sure people probably being extra prone to search explicit substances and to expertise each desired therapeutic and hostile outcomes.
To disentangle these prospects, long-term potential analysis is required to find out if character traits predict subsequent substance use, and whether or not repeated publicity can itself produce lasting psychological modifications. Understanding who takes these substances, the context by which they’re consumed, and the way people make that means from these experiences could also be simply as vital as understanding the pharmacological results of the substances themselves.
Assertion of pursuits
Matthew Cohen doesn’t know the researchers concerned on this examine. He has been a examine medic in psychedelic trials and has acquired fee for that work. AI was used to assist polish the textual content of this text to enhance readability.
Editor
Edited by Éimear Foley. ChatGPT assisted with language refinement and formatting through the editorial section.
Hyperlinks
Main paper
José Carlos Bouso, Jordi Riba et al (2026) Persona, not cognition, distinguishes continual ayahuasca and hashish customers from non-users. European Neuropsychopharmacology 106, 112782. https://doi.org/10.1016/j.euroneuro.2026.112782
Different references
Wickham R. Psychedelics and psychological well being: can the sector ship on its promise? The Psychological Elf, 2024.
Nationwide Elf Service weblog
De Bode N. Medical cannabinoids as a remedy for psychological well being: useful or hazardous? The Psychological Elf, 2024.
Nationwide Elf Service weblog
Henriques M. Australia turns into first nation to recognise psychedelics as medicines. BBC Information, 1 Jul 2023.
BBC Information article
Schreiner A.M, Dunn M.E. (2012) Residual results of hashish use on neurocognitive efficiency after extended abstinence: a meta-analysis. Experimental and Scientific Psychopharmacology 20(5), 420–429. Full textual content
De Vos C.M, Mason N.L, Kuypers Ok.P.C. (2021) Psychedelics and neuroplasticity: a scientific evaluation unraveling the organic underpinnings of psychedelics. Frontiers in Psychiatry 12, 724606. Full textual content
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