Valérie-Anne O'Callaghan
A growing narrative is circulating: that psilocybin, MDMA, ayahuasca, or cannabis could resolve what conventional therapy cannot. This message resonates particularly strongly with a specific population: neurodivergent individuals who have spent years searching for answers and often live with anxiety, depression, or chronic exhaustion.
The question that is almost never asked is whether the risk profile is the same. And it isn't.
I write this without any intention of prohibition. Decisions about one's own body are a personal one. What I believe is essential is that these decisions be made with complete information, and in this area, the information circulating is heavily biased towards enthusiasm.
The starting point: there is almost no data
That's the first thing you should know.
People with autism and ADHD are systematically excluded from clinical trials with psychedelics. What we know about efficacy and safety comes almost entirely from neurotypical populations, and its applicability to other neurological profiles remains unestablished.
The limited research specifically on autism falls into two categories. Trials conducted in the 1960s and 70s with LSD in children suffered from serious methodological problems, imprecise diagnostic criteria, and documented adverse effects including aggression, dissociative states, and psychotic episodes. These findings stifled research for decades.
And recent studies are very small. The most cited, by Danforth et al. (2018), worked with twelve autistic adults with severe social anxiety using MDMA in a controlled therapeutic setting, with improvements that were maintained at six months. Twelve people, with professional support, in a designed environment, and with prior selection. That result does not authorize any conclusions about someone who buys pills and goes to a festival.
There are ongoing trials, including work at King's College London on sensory processing with low doses of psilocybin. The results are coming, but they aren't available yet.
Ayahuasca: the risk that can kill
It is important to be categorical here, because this is the point where misinformation can have irreversible consequences.
Ayahuasca contains monoamine oxidase inhibitors (MAOIs). Combined with serotonergic antidepressants, including SSRIs, SNRIs, and St. John's wort, they can produce serotonin syndrome. Symptoms include confusion, muscle rigidity, high fever, seizures, and severe changes in blood pressure and heart rate. This is a medical emergency and can be fatal.
This matters especially in this population for a simple statistical reason: a very high proportion of neurodivergent adults take or have taken antidepressants, often prescribed by previous diagnoses that came before the neurodivergent profile was identified.
And there's an additional risk that's rarely mentioned. Retreat centers require discontinuing medication weeks in advance, sometimes six or eight weeks depending on the drug. Withdrawing an antidepressant without medical supervision, within the timeframe of a retreat, and under the pressure of a trip already paid for, is inherently dangerous: discontinuation syndrome, relapse, risk of decompensation.
The same precaution applies to MDMA combined with monoamine oxidase inhibitors, and to mixtures of stimulants with ayahuasca.
If you are taking psychiatric medication, this decision should be made by your doctor, not by a form from a retreat center.
Why the retirement context is especially demanding
This point is rarely raised, and I think it's one of the most relevant.
Think about what a typical retreat entails: traveling to an unfamiliar place, sleeping in a new environment, living in a group for days, eating what is served, following a schedule you don't control, participating in long ceremonies with intense music, strong smells, dim lighting, people around in altered states, physical contact not always announced, and an unpredictable duration.
Each of these elements represents a considerable burden for a nervous system with low sensory thresholds and a need for predictability. Combined, and under the influence of a substance that amplifies perceptual intensity, the overall effect can be overwhelming.
Markram and Markram (2010) proposed the intense world theory: hyperreactive circuits that produce a perception of overwhelming intensity. Adding a substance that amplifies perception to this base has a logic that should be considered before doing so.
And there's more. Many neurodivergent people have interoceptive difficulties, so they are slow to recognize their own state of overload. And many others have developed compliance responses that make it extremely difficult to say they want to stop. The combination of both, in an environment where stopping is frowned upon and interpreted as resistance to the process, is worrying.
Cannabis: the most widespread and the worst rated
Cannabis deserves its own section because it is, by far, the most used substance, frequently as a daily self-regulation tool for sleep, to reduce anxiety, or to tolerate sensory overload.
THC and the risk of psychosis. The association between cannabis use and psychosis is well-documented, dose-dependent, and the risk increases with earlier onset and greater frequency of use. The potency of cannabis available today is far greater than it was decades ago, which changes the calculation.
A potentially greater vulnerability. Clinical guidelines and recent reviews indicate that autistic individuals may be more likely to develop cannabis-related psychosis. They also add an important point: in autistic individuals, detecting psychotic symptoms is more difficult and often occurs later, because they overlap with pre-existing traits.
Brain development. Exposure to THC during adolescence and well into one's twenties coincides with the period of synaptic pruning and prefrontal maturation. Guidelines recommend avoiding THC before the age of twenty-six unless there is a strong clinical indication.
CBD is something else, and it's also limited. Cannabidiol has a distinct risk profile, and there are trials in autism using CBD-rich extracts. A recent meta-analysis identified only three randomized controlled trials, with a total of 276 participants and mixed results. Professional societies do not recommend cannabinoids for core features of autism based on current evidence.
And the practical problem. Cannabis works in the short term to lower arousal, and this immediate relief makes it easy to develop a habit. Over time, however, it often worsens deep sleep, motivation, and working memory—precisely the three areas where many neurodivergent people already struggle.
What can be stated is
I summarize the above in clear terms.
There is preliminary evidence that some of these substances could help autistic individuals with social anxiety or depression, in a controlled therapeutic setting and with professional support. This evidence comes from very small samples.
There is no evidence to support self-use, commercial retreats, or recreational use for this population.
There are specific documented risks: potentially fatal interaction with serotonergic antidepressants, a higher likelihood of adverse reactions described in older literature, a possibly increased risk of psychosis with THC, and a withdrawal context that is sensorially adverse by design.
And the most important thing is missing: we don't know how a nervous system with a different configuration responds to these substances, because it hasn't been studied.
If you're still going to do it
I prefer to say this rather than remain silent, because other people do it anyway and silence doesn't protect anyone.
Talk to your doctor about the medication you're taking before anything else. This part is non-negotiable and there are no shortcuts.
Check the training of the facilitator. Ask what they would do in a crisis, what access to medical care is available, and how far away the nearest hospital is.
Ask explicitly if it's possible to stop, leave the room, or abandon the ceremony without penalty. If that question makes you uncomfortable, you already have the answer.
Think about the environment using sensory criteria, not just emotional ones: noise, smells, light, presence of physical contact, duration, possibility of withdrawing.
And consider who will be with you afterward. The aftermath is just as important as the experience itself, and an overwhelmed nervous system needs recovery days that are best planned for.
What worries me most is...
The discourse promising transformation is precisely aimed at those who have long been exhausted and without answers. This combination of pent-up hope and quiet despair is exactly where risk is least accurately assessed.
And it's worth remembering something that doesn't sell well: most of what stabilizes a neurodivergent nervous system isn't flashy. Reducing sensory overload, sleeping better, masking less, adjusting demands, having someone secure nearby. Not very photogenic, and with more evidence behind it than any ceremony.
Sources and references
Bertelli, M.O., et al. (2022). Cannabis use in autism: reasons for concern about risk for psychosis. Healthcare, 10(8), 1553.
Danforth, A.L., et al. (2018). Reduction in social anxiety after MDMA-assisted psychotherapy with autistic adults: a randomized, double-blind, placebo-controlled pilot study. Psychopharmacology, 235(11), 3137-3148.
Markram, K. and Markram, H. (2010). The intense world theory: a unifying theory of the neurobiology of autism. Frontiers in Human Neuroscience, 4, 224. École Polytechnique Fédérale de Lausanne.
Porges, SW (2011). The Polyvagal Theory. WW Norton. Neuroscientist, Indiana University.
Trevisan, D.A., et al. (2019). A meta-analysis on the relationship between interoceptive awareness and alexithymia. Journal of Abnormal Psychology, 128(8), 765-776. Yale University.
Utah Department of Health and Human Services, Center for Medical Cannabis (2021). Evidence-based guidelines: autism. Clinical guide on cannabinoids in autism spectrum disorder.
Wolstencroft, J., et al. (2022). Evaluating the potential use of serotonergic psychedelics in autism spectrum disorder. Frontiers in Pharmacology.
Note: This article is for informational purposes only and does not replace medical advice. Any changes to psychiatric medication should be made under medical supervision.