An independent information page about truffle ceremonies

One of the best-known lines of research into psilocybin concerns what researchers call a "mystical-type experience". American researcher Roland Griffiths and colleagues at Johns Hopkins University first described this in detail in 2006, and follow-up research has repeatedly confirmed the findings since.¹⁰ It is a recognisable pattern: a sense of unity and connectedness with everything around you, timelessness, awe and wonder, and a temporarily less sharp boundary between the self and the world outside. Many people also describe it as an experience steeped in love.

What makes this research striking is how participants rate the experience afterwards. In several studies, a considerable share of participants ranked the experience among the most meaningful of their entire life, comparable to the birth of a child. Some participants also describe a gentler relationship to their own mortality, and existential insights that kept working through for a long time. Researchers see this mystical-type experience as one of the factors associated with positive effects in later research into, for example, depression and anxiety.

This experience often raises philosophical questions, and it helps to keep three layers apart. Subjectively, participants often describe something like "everything is one", a dissolving of the usual boundary between themselves and their surroundings. Researchers measure and describe this as a recognisable pattern of perceived unity, timelessness and meaning, without making a claim about the nature of reality. Spiritual traditions interpret such experiences in their own way in turn: the Buddhist idea of "non-self", for example, is mentioned by some as an interesting parallel. Scientific research does not prove that "everything is one", but it does describe that people can experience this in a convincing, personal way during and after an experience with psilocybin.

For a few years now, psilocybin has been studied as a possible treatment for treatment-resistant depression: depression that does not respond sufficiently to the usual treatments such as antidepressants and therapy. Research centres such as Johns Hopkins University and the Centre for Psychedelic Research at Imperial College London run clinical trials for this.

One of the most striking results came in 2021, when researchers from Imperial College London published in The New England Journal of Medicine that two psilocybin sessions in people with long-term, moderate to severe depression worked at least as well as six weeks of daily escitalopram, a commonly used antidepressant.¹³ For a treatment given in just two sessions, that is a notable outcome.

In this research, participants do not receive psilocybin as a standalone substance, like a pill you take at home. The sessions take place in a controlled, clinical setting, with extensive preparation beforehand, guidance during the session itself, and structured aftercare afterwards. Researchers regard that guidance as an essential part of the effect. In the Netherlands, psilocybin is not yet a recognised treatment within mental healthcare, but it is exactly this kind of research that is paving the way toward a possible future application.

One of the most frequently cited lines of research concerns people with a life-threatening diagnosis, such as metastatic cancer. Researchers such as Roland Griffiths (Johns Hopkins)¹¹ and Stephen Ross (New York University)¹² published studies in which participants with such a diagnosis received a single, high dose of psilocybin, in a carefully guided clinical setting.

The findings were striking: in a large share of participants, the fear of death noticeably decreased, and more acceptance of their situation emerged. What makes these studies remarkable is how long these effects lasted. At follow-up measurements, sometimes months or even years later, some participants reported that the reduced fear of death and increased acceptance had persisted, after a single session.

This research took place in intensive, therapeutically guided settings, with careful preparation, medical screening and professional aftercare focused specifically on this stage of life. It shows how deeply and how long a single, well-guided experience can continue to work through.

With PTSD (post-traumatic stress disorder) and trauma, extra caution and honesty are called for. Research into psilocybin specifically for PTSD is still at an early stage, with considerably less clinical data available than for depression or fear of death, for example.

The theory behind possible effects relates to two mechanisms. Psilocybin appears to temporarily reduce avoidance behaviour: the automatic mechanism by which people with trauma steer clear of painful memories and feelings. Researchers also see reduced activity in the so-called default mode network, the brain network associated with rumination and fixed thought patterns among other things, combined with a temporary increase in neuroplasticity: the ability of brain cells to form new connections.¹⁵ The idea is that these effects together can create room to approach traumatic memories with more inner distance.

This is largely theory, based on early and small studies. With current, severe PTSD, caution is essential: always consult a treating clinician first before considering a ceremony. This is explicitly not a recognised treatment for PTSD.

Psilocybin is also being studied as a possible aid for addiction, with most research so far focused on smoking addiction. A pilot study by Johns Hopkins University combined a limited number of psilocybin sessions with behavioural therapy guidance aimed at smoking cessation.¹⁴

The results were striking: of the fifteen participants, 80 percent were still not smoking after six months, a considerably higher percentage than is usually seen with standard treatments for smoking addiction. Researchers suspect that a combination of factors plays a role here, including breaking through entrenched habit patterns and the motivating effect of a meaningful experience.

This was a small, initial study, and follow-up studies into smoking addiction and other forms of addiction, such as alcohol addiction, are now underway. This early research does count among the most promising results within psychedelics research to date.

Not all meaningful effects of a truffle ceremony can be measured in a laboratory. Many people, also outside clinical research, say that a ceremony raises questions about what really matters in their life: about mortality, about connection with others, about love, and about choices they had long been putting off.

A possible explanation for this lies in the line of research into mystical-type experiences described above. The sense of unity, timelessness and the temporary letting go of the usual self-image studied there seems, for many people, to touch exactly the layer these kinds of life questions come from. Some people find words for that layer in spiritual traditions, such as the Buddhist idea of non-self, or simply by describing a feeling of "everything is one". Those are personal, meaningful interpretations, not scientific conclusions.

This section is deliberately less clinical than the other themes above. It is fair to note, though, that for many people this is one of the most commonly mentioned reasons to start a ceremony.