Psychedelic therapy
glossary

The session in which the psychedelic substance is actually taken — as distinguished from the preparation and integration sessions that surround it. In Oregon's licensed psilocybin framework, this is the specific term used for when clients consume a psilocybin product at a licensed service center under facilitator supervision.

A psychedelic brew made by combining two plants: Banisteriopsis caapi (which contains MAOIs) and Psychotria viridis (which contains DMT). The MAOI in the vine makes the DMT orally active. Ayahuasca has been used in Amazonian healing traditions for millennia. Sessions typically last 4–8 hours and involve intense physical purging alongside visionary and emotional experiences. Legal for ceremonial use in Brazil, Peru, and some other countries; Schedule I federally in the US.

A colloquial term for a psychedelic experience characterized by fear, paranoia, panic, or deeply uncomfortable psychological content. Harm reduction practitioners prefer difficult experience or challenging experience, because what feels "bad" during a session often yields meaningful insight in integration — and because framing the experience as inherently bad can make it harder to navigate. The clinical protocol response to a difficult experience is not suppression or rescue, but rather gentle encouragement to "move toward" the difficult material. See also: surrender, harm reduction.

A protein that promotes the growth, maintenance, and survival of neurons. Psychedelics — and ketamine — increase BDNF production, which is one of the proposed mechanisms behind their rapid antidepressant effects. Higher BDNF is associated with stronger synaptic connections and neuroplasticity. Interestingly, many conventional antidepressants also increase BDNF, but more slowly and through different pathways. The rapid BDNF boost from ketamine may explain why it relieves depression in hours rather than weeks.

An FDA designation for drugs that show preliminary clinical evidence of substantial improvement over existing therapies. It accelerates the review process but does not guarantee approval. Both psilocybin (for treatment-resistant depression and MDD, granted to Compass Pathways and Usona Institute) and MDMA (for PTSD, granted to MAPS/Lykos) received this designation — a meaningful signal that the FDA considered the early evidence compelling. The MDMA designation did not prevent the FDA from declining approval in 2024.

A structured ritual context for a psychedelic experience, typically rooted in indigenous healing traditions. A ceremony differs from a clinical session in that it is organized around spiritual or cultural frameworks rather than medical ones — often involving music, prayer, ceremonial objects, and traditional healing practices. Many practitioners blend ceremonial and clinical approaches. The container, music, and ritual structure of a ceremony are understood to shape the experience and its outcomes.

A metaphor for the physical, relational, and psychological conditions that hold a psychedelic experience safely. A strong container includes: a trusted guide or therapist, a comfortable and aesthetically considered physical space, clear agreements and informed consent, and adequate preparation time. The concept acknowledges that the setting is not passive — it actively shapes what arises and how safely difficult material can be explored. Creating a good container is a primary responsibility of the facilitator.

When tolerance to one psychedelic produces tolerance to another. Classic psychedelics (psilocybin, LSD, mescaline, DMT) all act primarily on 5-HT2A receptors and therefore show significant cross-tolerance with each other. Taking psilocybin on Monday and LSD on Thursday will produce a much weaker LSD experience than expected. This is why protocols like Fadiman include rest days — and why experienced users space different substances by at least two weeks for full effect. Ketamine and MDMA do not share this cross-tolerance profile.

A traditional healer in Latin American indigenous cultures, often using plant medicines including ayahuasca, psilocybin mushrooms, or other entheogens in their practice. The curandero/a role encompasses years or decades of apprenticeship, specialized ritual knowledge, and spiritual authority within their community. Many ayahuasca retreat centers work with curanderos from Shipibo, Quechua, or other Amazonian traditions. The term should not be applied casually to any psychedelic facilitator — it carries specific cultural weight.

A network of brain regions most active during rest, self-referential thought, mind-wandering, and rumination. The DMN is sometimes described as the "default" mode because it activates when we're not focused on a specific external task. It is heavily implicated in the narrative sense of self — the ongoing story we tell about who we are. Psychedelics consistently and dramatically reduce DMN activity, which correlates with the ego dissolution experience. Overactive DMN function is associated with depression and anxiety; the dampening of DMN activity may be part of how psychedelics produce therapeutic effects.

A preparatory practice in Amazonian plant medicine traditions involving dietary restrictions (no pork, alcohol, sugar, salt, or sex) for a period before and after an ayahuasca ceremony. In traditional Shipibo practice, the dieta can last weeks or months and may involve extended isolation with a particular plant teacher. Many modern retreat centers ask for a simplified dieta of a few days to a week. The dieta is understood not merely as dietary preparation but as a relational and spiritual commitment to the healing process.

A powerful, rapidly-acting psychedelic tryptamine found in many plants and animals. When smoked or vaporized, DMT produces an intense 10–20 minute experience. When consumed as part of ayahuasca (with MAOI-containing plants), it becomes orally active for 4–8 hours. DMT naturally occurs in the human body, though its endogenous role is not well understood. Schedule I in the US. Under Colorado's Proposition 122, DMT may eventually be added to the list of regulated natural medicines after June 2026.

The temporary loss of the ordinary sense of self — the autobiographical "I" that organizes continuous identity. During ego dissolution, the boundary between self and world softens or disappears. This can be experienced as terrifying (particularly if unexpected) or profoundly peaceful, depending on set and setting and the individual's relationship with the experience. The phenomenon is closely linked to the default mode network (DMN) quieting under psychedelics. Ego dissolution is not actual death of the ego's functional capacities — which remain intact — but rather a temporary loosening of the identifying narrative self. Research suggests that the depth of ego dissolution correlates with therapeutic outcomes in depression and end-of-life anxiety.

A class of psychoactive substances that primarily produce feelings of emotional openness, closeness to others, and heightened empathy — distinct from the classic psychedelics which produce more perceptual and consciousness-altering effects. MDMA is the primary example. The term entactogen (from Latin en "within," tactus "touch") emphasizes the sense of emotional contact the drug facilitates. These work through serotonin, dopamine, and norepinephrine release rather than primarily through 5-HT2A receptor agonism.

From the Greek: en (within) + theos (god) + gen (to generate) — "generating the divine within." A term coined in 1979 as a more precise and culturally respectful alternative to hallucinogen or psychedelic, specifically for substances used in spiritual or religious contexts. The distinction matters: the same molecule can be a recreational drug, a psychedelic medicine, or an entheogen depending on the intention and context of its use. Peyote in Native American Church practice is an entheogen; psilocybin in a clinical trial is a psychedelic medicine. Context and intention are not trivial.

The S-enantiomer of ketamine — one of ketamine's two mirror-image molecular forms. Esketamine is the active form as a nasal spray, FDA-approved in 2019 for treatment-resistant depression and in 2020 for MDD with acute suicidal ideation or behavior (under the brand name Spravato). Because it has FDA approval, esketamine/Spravato is covered by many insurance plans with prior authorization — a significant advantage over off-label IV ketamine infusions. Must be administered in a certified medical setting with 2-hour monitoring.

A trained practitioner who supports a person through a psychedelic experience. In Oregon's licensed psilocybin framework, "facilitator" is the specific legal term for a licensed provider. More broadly, the role involves creating the container, conducting preparation and integration sessions, and being present during the session itself. Facilitators are distinct from therapists (who conduct ongoing psychotherapy), though many facilitators have therapeutic training. The Fadiman and Stamets protocols for microdosing were developed by people known for their facilitation work and research.

The most widely used microdosing schedule, developed by psychologist Dr. James Fadiman: one day of microdosing followed by two rest days, repeated for 4–8 weeks before a break. The rest days allow tolerance to reset and enable observation of the contrast between dose and non-dose days. Fadiman collected self-reported microdosing data from thousands of people worldwide over several decades, forming the observational basis for current microdosing practice.

The primary receptor through which classical psychedelics (psilocybin, LSD, DMT, mescaline) produce their effects. When these drugs bind to 5-HT2A receptors in the prefrontal cortex and other brain regions, they trigger a cascade of downstream effects including increased glutamate release, reduced default mode network activity, and enhanced neuroplasticity. 5-HT2A agonism is what distinguishes classical psychedelics from empathogens like MDMA (which work primarily through serotonin release) and dissociatives like ketamine (which work through NMDA receptor antagonism).

A powerful psychedelic found in several plants and in the venom of the Sonoran Desert toad (Bufo alvarius). Effects begin within seconds of inhalation and last 15–45 minutes — far more intense and shorter than psilocybin. Often described as producing a complete dissolution of identity, sometimes experienced as a "reset." Legal in Mexico, where several retreat centers administer it — often in combination with ibogaine. Conservation concerns around Sonoran Desert toad harvesting are serious; synthetic 5-MeO-DMT is ethically preferable. Schedule I in the US.

An informal term for someone who accompanies another through a psychedelic experience. In non-clinical and underground contexts, guides operate without formal licensure. In clinical and ceremonial contexts, the term is often used interchangeably with facilitator or sitter. A good guide has personal experience with the substance, training in psychological support, and a non-directive stance — meaning they don't try to shape the experience toward a particular outcome. The Zendo Project's harm reduction model distinguishes between guides and sitters based on level of training and experience.

An older clinical and regulatory term for substances that produce perceptual distortions, visions, and altered states of consciousness. Still used in pharmacological and regulatory writing. Many researchers and practitioners consider it imprecise or misleading — "hallucination" implies seeing things that aren't there, but many psychedelic experiences involve enhanced perception of things that are there, or profound internal states with no visual component at all. Psychedelic (mind-manifesting) and entheogen are often preferred in clinical and spiritual contexts respectively.

A public health approach that aims to reduce the negative consequences of drug use without requiring abstinence. In the psychedelic context, harm reduction includes: accurate information about risks, drug checking services (testing substances for purity), peer support at events and festivals, and crisis support services like the Fireside Project. The Zendo Project is the field's leading harm reduction organization. Harm reduction recognizes that people will use psychedelics regardless of legal status, and focuses on making that use as safe as possible.

A rare condition in which visual or perceptual disturbances from a psychedelic experience persist or recur after the drug has left the body — sometimes for months or years. Symptoms range from visual snow and trailing after-images to more pronounced distortions. HPPD is distinct from a simple flashback and represents a persistent neurological change. Estimated prevalence is less than 1% of people who use psychedelics, though milder perceptual aftereffects are more common. Risk factors include frequent high-dose use, pre-existing anxiety, and combining substances. There is no established treatment; benzodiazepines and antipsychotics are sometimes used with mixed results.

Ibogaine is the primary psychoactive alkaloid from the iboga plant (Tabernanthe iboga), sacred in the West African Bwiti tradition. A single ibogaine experience lasts 24–36 hours and is notable for producing what users describe as a "film" of autobiographical memories. Ibogaine has shown remarkable results for opioid addiction, including dramatically reducing withdrawal symptoms, and for PTSD in veterans — but carries serious cardiac risk (QTc prolongation) requiring cardiac monitoring. Legal and clinically administered in Mexico, Portugal, and several other countries; Schedule I in the US. Stanford's 2024 study of veterans was significant.

The process of making sense of a psychedelic experience and bringing insights into daily life. Integration is considered by most clinical practitioners to be as important as the experience itself — the session opens material, integration is where the work happens. It involves practices like journaling, therapy, somatic work, and community support, and it unfolds over weeks or months. Poorly integrated experiences are associated with worse outcomes; well-supported integration is associated with lasting benefit. The field is increasingly recognizing "integration therapy" as a distinct specialty.

A psychotherapy model developed by Richard Schwartz that views the psyche as made up of distinct "parts" — each with its own perspectives, feelings, and roles — organized around a core Self. IFS has become widely used in psychedelic integration because the psychedelic experience often makes these parts more vivid and accessible. Many facilitators specifically trained in IFS use it to work with material that arises during sessions. The model's emphasis on compassion toward all parts — even protective or defensive ones — fits well with the psychedelic therapeutic approach.

A format of ketamine treatment in which a licensed therapist is present throughout the ketamine session, using the drug's effects to facilitate deeper psychological work. KAP is distinguished from simple ketamine infusions by the presence of an active therapeutic relationship during the session itself. Research suggests KAP produces better and more sustained outcomes than infusion alone, particularly for trauma and depression with psychological complexity. Field Trip Health is notable for standardizing KAP at all their locations.

A dissociative anesthetic with powerful rapid-onset antidepressant effects. Unlike classical psychedelics, ketamine works primarily as an NMDA receptor antagonist rather than a serotonin agonist. Legal for medical use in the US — administered off-label for depression, PTSD, and chronic pain as IV infusions or intramuscularly; and on-label as esketamine nasal spray (Spravato) for treatment-resistant depression. The only legal psychedelic-adjacent therapy available in all 50 states right now. Effects are typically felt within hours, lasting days to weeks from a single infusion.

A semisynthetic psychedelic compound first synthesized by Albert Hofmann in 1938. Active at doses measured in micrograms (µg) — far smaller than psilocybin. Effects begin 30–60 minutes after ingestion and last 8–12 hours, significantly longer than psilocybin. Primarily a 5-HT2A agonist. The longer duration is practically significant — LSD taken in the afternoon will affect sleep. Schedule I in the US. The most studied psychedelic in early research (1950s–70s) and the most precisely doseable due to the tiny active quantities.

A full psychedelic dose — as opposed to a microdose. In psilocybin, a macrodose is typically 3–5g dried mushrooms (producing a full psychedelic experience) versus a microdose of 0.05–0.3g. A "heroic dose" (term coined by Terence McKenna) refers to very high doses, typically 5g or more of dried psilocybin mushrooms, intended to produce complete ego dissolution. Clinical trial doses for therapeutic psilocybin are typically 25mg pure psilocybin (equivalent to roughly 3–4g dried mushrooms).

A class of drugs that inhibit the enzyme monoamine oxidase, preventing the breakdown of monoamine neurotransmitters including serotonin, dopamine, and norepinephrine. MAOIs are both a class of antidepressant medication and a natural component of ayahuasca (the Banisteriopsis caapi vine). In ayahuasca, the MAOI allows oral DMT to become active by preventing its breakdown in the gut. Combining an MAOI antidepressant with psilocybin, MDMA, or ayahuasca is dangerous — it can cause serotonin syndrome, a potentially life-threatening condition.

A nonprofit founded by Rick Doblin in 1986, focused on developing psychedelic medicines through clinical research and advocacy. MAPS conducted the pivotal Phase 3 trials for MDMA-assisted therapy for PTSD, developed the MAPS treatment protocol and therapist training program, and maintains the MAPS Integration List of therapists. In 2024, MAPS's subsidiary Lykos Therapeutics received an FDA Complete Response Letter declining to approve MDMA therapy — a setback, though research continues.

An empathogen/entactogen that produces intense feelings of emotional openness, closeness, and reduced fear response — distinct from classical psychedelics. MDMA releases serotonin, dopamine, and norepinephrine, creating 3–5 hours of effects. Used in the MAPS Phase 3 trials for PTSD, producing some of the most dramatic results in psychiatric research history (67% no longer met PTSD criteria vs. 32% placebo). Schedule I in the US. Not FDA-approved after the 2024 CRL decision. Formally approved in Australia as of 2023 for PTSD.

Taking sub-perceptual doses of a psychedelic — typically 1/10th to 1/20th of a full dose — at regular intervals, usually every few days. The goal is subtle benefit (mood, focus, creativity) without intoxication. Popularized by Dr. James Fadiman. Evidence is real but more modest than advocates claim; the research base is growing but most RCTs show more limited cognitive benefits than observational reports suggest.

A profound altered state characterized by a sense of unity with all things, transcendence of time and space, noetic quality (the sense of having encountered deep truth), sacredness, deeply felt positive mood, and ineffability (difficulty putting the experience into words). Walter Pahnke identified these qualities in his 1962 "Good Friday Experiment." Importantly, the depth of mystical experience in clinical trials correlates with therapeutic outcomes — participants who report stronger mystical experiences show greater reductions in depression, anxiety, and addiction at follow-up. This is why researchers believe the experience itself, not just the pharmacology, is therapeutically active.

The brain's ability to form new neural connections and reorganize existing ones. Psychedelics are now understood to be potent promoters of neuroplasticity — UC Davis researcher David Olson coined the term psychoplastogen for this class of compounds. Even at sub-perceptual doses, psychedelics increase dendritic spine density and synaptic connectivity. This structural remodeling may explain why a small number of psychedelic sessions can produce lasting therapeutic effects — the brain is physically more capable of forming new patterns of thought and feeling during the "plasticity window" following a session.

A glutamate receptor involved in synaptic plasticity, memory formation, and pain processing. Ketamine — and dissociatives like PCP — produce their effects by blocking NMDA receptors. This is mechanistically distinct from how classical psychedelics work (via 5-HT2A agonism). NMDA antagonism triggers downstream glutamate release, BDNF production, and rapid antidepressant effects. Understanding NMDA receptor function has been central to explaining why ketamine works so much faster than conventional antidepressants.

A dimension of altered consciousness measured by the 5D-ASC (Five Dimensional Altered States of Consciousness) questionnaire — one of the primary research tools used in psychedelic studies. Oceanic boundlessness refers to the positively experienced dissolution of ego boundaries: feelings of unity, bliss, and transcendence. It is contrasted on the scale with dread of ego dissolution — the same loss of boundaries experienced as frightening rather than liberating. The balance between these poles is significantly influenced by set and setting.

The work done before a psychedelic session to maximize safety and therapeutic potential. In clinical trials, preparation typically involves 2–5 sessions of psychotherapy exploring the person's history, intentions, concerns, and expectations. The therapeutic relationship established in preparation is considered foundational — research suggests that the quality of the therapeutic alliance predicts outcomes more than any other measurable variable. Preparation also includes medical screening, informed consent, logistics (who will pick you up, where you'll sleep), and setting intentions.

Psilocybin is a prodrug found in over 200 species of fungi. The body converts psilocybin to psilocin, the active compound, which binds primarily to 5-HT2A receptors. Effects begin 30–60 minutes after ingestion and last 4–6 hours. FDA has granted Breakthrough Therapy Designation for psilocybin therapy for treatment-resistant depression and MDD. Licensed for supervised therapeutic use in Oregon and Colorado. Decriminalized in several US cities. Legal in Jamaica, Netherlands (truffles). The most studied psychedelic in current clinical research.

From the Greek psyche (mind/soul) + delos (to reveal) — "mind-manifesting." The term was coined by psychiatrist Humphry Osmond in 1957 in correspondence with Aldous Huxley. Classical psychedelics (psilocybin, LSD, DMT, mescaline) share the mechanism of 5-HT2A receptor agonism. In broader usage, "psychedelic" is sometimes applied to ketamine, MDMA, ibogaine, and cannabis — substances that produce profound altered states through different mechanisms. The clinical and cultural boundaries of the word are actively debated.

A treatment model in which psychedelic substances are used as adjuncts to psychotherapy, rather than as standalone pharmacological interventions. The key distinction: the drug is understood as a catalyst for psychological work, not the treatment itself. Standard protocols involve multiple preparation sessions, one or more medicine sessions (often with the therapist present), and multiple integration sessions. This is different from, say, taking an SSRI daily — there is no equivalent of psychedelic "maintenance dosing." The most studied versions use psilocybin and MDMA.

A term coined by UC Davis researcher David Olson for compounds that rapidly promote neural plasticity. Psychoplastogens include classic psychedelics, ketamine, and related compounds. Olson's research group is developing non-hallucinogenic psychoplastogens — molecules that provide the neuroplasticity benefits of psychedelics without the altered consciousness. This research direction could eventually produce treatments that achieve similar therapeutic effects with less disruption to daily functioning.

The most restrictive category under the US Controlled Substances Act, defined as substances with "no currently accepted medical use and a high potential for abuse." Psilocybin, LSD, MDMA, DMT, ibogaine, and mescaline are all Schedule I. The Schedule I designation creates a circular problem: it limits research funding while also being used to justify continued scheduling. The FDA's Breakthrough Therapy Designations for psilocybin and MDMA acknowledged therapeutic potential despite Schedule I status.

The two primary factors shaping a psychedelic experience. Set refers to the internal environment — mindset, intentions, emotional state, expectations, relationship with the guide, psychological history. Setting refers to the external environment — physical space, music, lighting, who is present, the legal and cultural context. The concept was developed by Timothy Leary in the 1960s but is now firmly established in clinical research: the same dose of psilocybin produces vastly different experiences depending on set and setting. This is why clinical protocols invest heavily in preparation and environmental design — the container shapes the content.

A potentially life-threatening condition caused by excess serotonergic activity in the nervous system — typically resulting from combining multiple serotonergic drugs. Symptoms range from mild (shivering, diarrhea) to severe (fever, muscle rigidity, seizures, death). Relevant combinations to avoid: MDMA + SSRIs, MDMA + MAOIs, psilocybin + MAOIs at high doses. Symptoms typically appear within hours of combining drugs. Medical emergency — requires immediate hospital care. A key reason why medication screening before any psychedelic session is non-negotiable.

An indigenous people of the Peruvian Amazon with a centuries-old tradition of ayahuasca healing. Shipibo curanderos are among the most sought-after traditional healers in the global retreat industry, and several Peruvian retreat centers are specifically rooted in Shipibo healing traditions. Shipibo healing involves icaros (healing songs), arkanas (protective chants), and working with the plant spirit of ayahuasca. The appropriation of Shipibo practices by non-indigenous retreat operators is an active ethical concern in the field.

A person who remains present during a psychedelic experience without actively facilitating or guiding it — holding space, ensuring physical safety, and being available if needed. In underground contexts, sitters often have less formal training than guides or facilitators. In clinical contexts, a "sitter" or "monitor" role may be distinct from the primary therapist. The Zendo Project trains harm reduction sitters specifically for festival and event contexts.

The most common class of antidepressant medication (Prozac, Zoloft, Lexapro, etc.). SSRIs work by blocking the reabsorption of serotonin, increasing its availability in synapses. Chronic SSRI use downregulates 5-HT2A receptors — the same receptors through which classical psychedelics produce their effects — which is why people on SSRIs often experience blunted or blocked psychedelic responses. Tapering off SSRIs before a psychedelic session is sometimes considered but carries real risks and should only be done with medical supervision. Never stop SSRIs abruptly.

A microdosing protocol and supplement combination developed by mycologist Paul Stamets: psilocybin mushrooms + Lion's Mane mushroom + niacin (vitamin B3), taken 5 days on / 2 days off. The theoretical rationale is that psilocybin promotes neuroplasticity, Lion's Mane (which contains NGF — Nerve Growth Factor) enhances neurogenesis, and niacin acts as a carrier helping distribute compounds. The neuroplasticity rationale is scientifically plausible; the specific combination has not been formally tested in controlled human trials.

In psychedelic therapy contexts, surrender refers to releasing resistance to the experience — allowing what arises to be present without fighting it. Clinical protocols across MAPS, Hopkins, and Imperial all teach some version of "trust, let go, be open" as the core instruction for navigating a session. Resistance and control-seeking are consistently associated with more difficult experiences; surrender and acceptance with more therapeutically productive ones. Surrender is not passivity — it is an active choice to remain present and open to whatever emerges.

The formation of new synapses — connection points between neurons. Psychedelics promote synaptogenesis rapidly, increasing the density of dendritic spines (the receiving ends of synaptic connections) in the prefrontal cortex and other regions. This is part of the neuroplasticity effect and is one proposed mechanism for lasting therapeutic benefit from a small number of sessions. The brain becomes structurally more connected and flexible in the period following a psychedelic experience.

The quality of the relationship between a client and therapist/facilitator — including trust, agreement on goals, and sense of collaboration. Research in standard psychotherapy finds therapeutic alliance is the strongest predictor of outcomes, more than the specific technique used. This appears to hold in psychedelic therapy as well — the quality of relationship established during preparation sessions significantly predicts the depth and benefit of the psychedelic session itself. A primary reason why good facilitation is not interchangeable with simple drug administration.

The reduction in response to a drug following repeated use, requiring a higher dose to achieve the same effect. Classical psychedelics develop tolerance extremely rapidly — taking psilocybin on consecutive days produces dramatically diminished effects on the second and third days. This is why protocols include mandatory rest days. Tolerance fully resets within 1–2 weeks of abstinence. Classical psychedelics are not associated with physiological dependence or withdrawal — but their rapid tolerance is why daily use is ineffective and pointless.

Depression that has not responded adequately to at least two different antidepressant medications tried at therapeutic doses for adequate duration. TRD affects approximately 30% of people with major depressive disorder. It is the primary target population for both FDA-approved esketamine (Spravato) and the psilocybin research receiving Breakthrough Therapy Designation from the FDA. TRD patients are often the focus of psychedelic trials because conventional treatments have already failed them — making the risk-benefit calculation more favorable for experimental approaches.

A traditional nighttime psilocybin mushroom ceremony in Mazatec indigenous culture, typically conducted by a curandera (female healer) and involving singing, prayer, and healing work in darkness. The Mazatec curandera María Sabina is credited with introducing the velada to Western knowledge when she shared the ceremony with R. Gordon Wasson in 1955 — an encounter Wasson later publicized in Life magazine, launching modern Western interest in psilocybin mushrooms. Several retreat centers in Oaxaca, Mexico, offer velada-rooted experiences.

The period following a psychedelic session — estimated at 1–4 weeks — during which the brain exhibits heightened neuroplasticity. New neural connections are more easily formed; habitual patterns are more flexible; psychological work is believed to be more effective. Integration therapy, journaling, lifestyle changes, and somatic practices during this window are thought to be especially important. This is one theoretical explanation for why what happens in the weeks after a session matters as much as the session itself.