During the last 20 years, analysis into psychedelic and cannabinoid-based therapies for psychological well being problems has quickly expanded.
Classical psychedelics (LSD, psilocybin and DMT) are being investigated as therapies for despair and nervousness (Wickham, 2024) and cannabis-based medicines are being more and more explored for a variety of indications from insomnia to tic problems, and autism (De Bode, 2024).
Because the scientific group 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 grew to become the primary nation to licence psilocybin as a remedy for despair 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 personal sector.
As these beforehand prohibited substances change into 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 persona, cognition and psychological well being.
Strategies
This was a cross-sectional examine based mostly in Spain evaluating measures of persona, cognition, and psychological well being between ayahuasca, hashish, and non-regular substance customers.
Ayahuasca customers had been members of the Spanish Santo Daime Church, a spiritual group the place ayahuasca is consumed ceremonially, whereas hashish customers had been members of Catalan cannabis-activist teams.
Individuals attended a screening go to, then a examine go to the place a battery of neuropsychological, persona and psychological well being scales had been accomplished. To be included members wanted to be abstinent from ayahuasca for 10 days, and hashish for 30 days previous to the examine go to, and have a unfavourable urine drug take a look at on the day.
To determine how persona, 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 had been included.
Variables had been entered into the MLR in levels (stepwise strategy). At every stage non-significant predictors had 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 members: 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 occasions and hashish customers over 33,000 occasions.
The ultimate mannequin had an adjusted R2 worth of 28% which means that the included predictors defined 28% of the variability in group membership.
Stage 1: sociodemographic, psychiatric historical past and IQ
Hashish customers had been youthful, extra prone to be male, have decrease instructional attainment and better fluid intelligence than non-user controls. Ayahuasca customers had been extra prone to have a earlier despair or nervousness prognosis than non-users. When these variables had been added into the MLR, solely age, intercourse and former despair prognosis remained statistically important predictors of group membership. This preliminary mannequin defined 8% of variability in group membership.
Stage 2: neuropsychological assessments
There have been no statistically important variations throughout person teams on measures of government functioning, working reminiscence, selective consideration, cognitive flexibility or choice making. These measures had been subsequently 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 had been subsequently not retained, suggesting the presence of psychological well being signs was much less essential 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 greater self-transcendence, and decrease persistence and hurt avoidance to wholesome controls. Hashish customers, however, demonstrated higher novelty searching 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 essentially 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 persona. Whereas person teams had substantial lifetime substance use, no variations had been recognized in assessments of government 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 greater self-transcendence and decrease persistence and harm-avoidance to non-users, whereas hashish customers demonstrated higher novelty searching for.
Strengths and limitations
Learning the long-term results of a drug is difficult. Customers typically devour a number of substances, differ in essential sociodemographic traits, and should have co-morbid psychological well being circumstances. In an try and minimise the affect of those confounding variables, Bouso et al. (2026) adopted a singular naturalistic design, recruiting members from established social teams the place ayahuasca (Santo Daime church) or hashish (hashish activist networks) use was an built-in cultural observe.
Whereas this strategy strengthens the examine via improved ecological validity by capturing functioning people with real-world publicity fairly than skewed treatment-seeking populations, it seemingly launched choice bias. Spiritual organisations and activist networks could entice people with distinct beliefs, values and attitudes unbiased of substance use. Consequently, though the noticed persona profiles had been in line with earlier analysis (greater self-transcendence in ayahuasca customers and novelty searching for in hashish customers), it’s unclear whether or not these variations replicate group 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 can also 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, members 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 should have contributed to the findings. Moreover, whereas the recruitment strategy 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 despair 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 unfavourable drug take a look at earlier than participation. That is notably essential when investigating cognition, as earlier meta-analyses recommend that many cognitive deficits related to hashish use diminish following extended abstinence (Schreiner & Dunn, 2012). That mentioned, the 10-day abstinence interval for ayahuasca customers was supposed to scale back acute results, nevertheless 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 assessments assessing quite a lot of cognitive domains, alongside questionnaires measuring psychopathology and persona. 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 USA ran an commercial evaluating the consequences of medication 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 assessments, the outcomes require cautious interpretation. Sure, ayahuasca and hashish customers on this examine didn’t differ from controls on measures of working reminiscence, government 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 could diminish following extended abstinence (Schreiner & Dunn, 2012). Nevertheless, earlier critiques 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 potential that people who skilled dangerous cognitive or psychological well being penalties arising from hashish had been much less prone to be recruited as a result of that they had already stopped utilizing hashish or had been not a part of these socially built-in communities. Due to this fact, the examine’s pattern could signify a subgroup of customers who can tolerate these substances or who had greater baseline cognitive functioning, maybe mirrored by the excessive fluid intelligence noticed amongst hashish customers.
Whereas the restrictions of the persona findings have already been mentioned, the variations noticed between ayahuasca and hashish customers are notably fascinating provided that particular person variations could affect one’s response to psychoactive substances. This can be a central assumption in psychedelic analysis, the place “set” (a person’s mindset, expectations and persona) and “setting” (the social, cultural and bodily atmosphere wherein 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). Due to this fact, when character dimensions equivalent to self-transcendence are greater in ayahuasca customers this may occasionally not merely signify an impact of the drug or the kind of particular person drawn to ayahuasca. As a substitute, it could replicate an interplay between persona, the cultural context of use, and the drug’s pharmacological results. This interplay could have essential medical implications as psychedelic- or cannabis-based therapies enter medical observe, with sure people probably being extra prone to search specific substances and to expertise each desired therapeutic and opposed outcomes.
To disentangle these prospects, long-term potential analysis is required to find out if persona traits predict subsequent substance use, and whether or not repeated publicity can itself produce lasting psychological modifications. Understanding who takes these substances, the context wherein they’re consumed, and the way people make which means from these experiences could also be simply as essential 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 obtained cost 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 part.
Hyperlinks
Major paper
José Carlos Bouso, Jordi Riba et al (2026) Persona, not cognition, distinguishes power 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 sphere 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 evaluate unraveling the organic underpinnings of psychedelics. Frontiers in Psychiatry 12, 724606. Full textual content
Kroon E, Kuhns L, Cousijn J. (2021) The short-term and long-term results of hashish on cognition: current advances within the discipline. Present Opinion in Psychology 38, 49–55. Full textual content
Lorenzetti V, Hoch E, Corridor W. (2020) Adolescent hashish use, cognition, mind well being and academic outcomes: a evaluate of the proof. European Neuropsychopharmacology 36, 169–180. Full textual content
Griffiths R.R, Richards W.A, McCann U. et al (2006) Psilocybin can event mystical-type experiences having substantial and sustained private which means and non secular significance. Psychopharmacology 187(3), 268–283. Full textual content
Carhart-Harris R.L, Roseman L, Haijen E. et al (2018) Psychedelics and the important significance of context. Journal of Psychopharmacology 32(7), 725–731. Full textual content
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