|Summary sheet: Psilocybin mushrooms|
Psilocybin mushrooms (commonly referred to as magic mushrooms, mushrooms, and shrooms) are a family of mushrooms that contain a mixture of psychoactive indole alkaloids, particularly the tryptamines psilocybin, psilocin, baeocystin, and norbaeocystin. When consumed, these mushrooms produce "classical psychedelic" effects (i.e. those associated with Mescaline, LSD, psilocybin mushrooms and DMT).
As the name implies, the principal psychoactive component of these mushrooms is psilocybin, which is thought to be converted into psilocin in the body before exerting their characteristic psychedelic effects. Both psilocybin and psilocin share a close structural relationship with the powerful visionary entheogen DMT, as well as the endogenous neurotransmitter serotonin.
Psilocybin mushrooms have been noted for their connection to a number of shamanic and ceremonial traditions among various cultures that used these mushrooms to produce visionary or entheogenic states of consciousness for spiritual or religious purposes.
Unlike most highly prohibited substances, psilocybin-containing mushrooms are not considered to be toxic or addictive by the scientific community. Nevertheless, unpredictable adverse reactions such as anxiety, paranoia, delusions and psychotic breaks can still always occur, particularly among those predisposed to psychiatric conditions. While these negative reactions or "bad trips" can often be attributed to factors like the user's inexperience or inadequate preparation of set and setting, they have been known to happen spontaneously among even the most experienced of users as well.
- 1 History and culture
- 2 Chemistry
- 3 Pharmacology
- 4 Subjective effects
- 5 Natural occurrence
- 6 Common usage
- 7 Research
- 8 Toxicity and harm potential
- 9 Legal status
- 10 See also
- 11 External links
- 12 Literature
- 13 References
History and culture
This History and Culture section is a stub.
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Psilocybin mushrooms may have been used since prehistoric times. Evidence shows that they have been consumed by ancient cultures since as far back as 7000 B.C. They are possibly depicted in Stone Age rock art in Europe and Africa, and have a history of use in pre-Columbian Mesoamerica. Many cultures have used these mushrooms in their religious rites and ceremonies.
Psilocybin mushrooms are the most commonly used form of psilocybin and psilocin. They have likely been used since prehistoric times and may have been depicted in ancient rock art. There are hypotheses of psilocybin mushrooms playing an evolutionary role in the advancement of human consciousness and language.
Many cultures such as the Mazatecs and even the Aztecs have used these mushrooms in religious rites for centuries and are still used today in Oaxaca, Mexico by the indigenous Mazatec people for divinatory purposes. In modern Western society, they are used medicinally, recreationally, scientifically and spiritually for their psychedelic effects.
Psilocybin, or 4-phosphoryloxy-N,N-dimethyltryptamine (4-PO-DMT), is an organic indole alkaloid molecule of the tryptamine chemical class. Tryptamines share a core structure comprised of a bicyclic indole heterocycle attached at R3 to an amino group via an ethyl side chain. 4-PO-DMT is substituted at R4 of its indole heterocycle with a phosphoryloxy (-PO) functional group; it also contains two methyl groups CH3- bound to the terminal amine RN. This makes psilocybin the 4-phosphoryloxy ring-substituted analog of DMT, and is largely thought to be inactive until it dephosphorylates into psilocin (4-HO-DMT) by the alkaline phosphatase enzyme, via hydrolysis..
Psilocin's psychedelic effects are believed to come from its efficacy at the 5-HT2A receptor as a partial agonist. Unlike LSD, this compound has no significant effect on dopamine receptors and only affects the noradrenergic system at very high dosages. However, the role of these interactions and how they result in the psychedelic experience continues to remain unknown and is subject to ongoing scientific investigation.
The effects listed below are based upon the subjective effects index and personal experiences of PsychonautWiki contributors. The listed effects should be taken with a grain of salt and will rarely (if ever) occur all at once, but heavier doses will increase the chances and are more likely to induce a full range of effects. Likewise, adverse effects become much more likely on higher doses and may include serious injury or death.
- Sedation - In terms of its effects on the physical energy levels of the user, psilocybin is considered by most to be relaxing, stoning and mildly sedating. This sense of sedation is often accompanied by compulsive yawning.
- Perception of bodily heaviness- This effect corresponds to the general sense of sedation and relaxation that characterizes psilocybin experiences, this manifests as a bodily heaviness that discourages movement but is typically only prominent during the first half of the experience. This particular physical effect seems to be more commonly experienced and pronounced with certain “woodlover” species of mushrooms such as Psilocybe azurescens.
- Spontaneous physical sensations - The "body high" of psilocybin can be described as a pleasurable, soft and all-encompassing tingling sensation or glow. This maintains a consistent presence that steadily rises with the onset and hits its limit once the peak has been reached. Once the peak of the experience or sensation is reached it can feel incredibly euphoric and tranquil or heavy and immobilizing depending on the dose.
- Tactile enhancement - This effect is less prominent than with that of LSD or 2C-B but is still present and unique in its character. It is repeatedly described as feeling very primitive in its nature often times with the small hairs on the user's arms or legs feeling slightly itchy or even ticklish against the skin.
- Changes in felt bodily form - This effect is often accompanied by a sense of warmth or unity and usually occurs around the peak of the experience or directly after. Users can feel as if they are physically part of or conjoined with other objects. This is usually reported as feeling comfortable in its sensations and even peaceful.
- Nausea - This effect can be greatly lessened or even completely avoided if the individual has an empty stomach prior to ingestion. It is often recommended that one either refrain from eating for approximately 6 to 8 hours beforehand, or eat a light meal 3 to 4 hours before if they are feeling physically fatigued.
- Changes in felt gravity
- Excessive yawning - This effect seems to be uniquely pronounced among psilocybin and related tryptamines. It can occur to a lesser degree on LSD and very rarely on psychedelic phenethylamines like mescaline. It typically occurs in combination with watery eyes.
- Watery eyes
- Frequent urination
- Muscle contractions
- Olfactory hallucinations
- Pupil dilation
- Runny nose
- Brain zaps - Although this effect is very rare, it can still occur for those susceptible to it. This component is however much less common and intense than it is with serotonin releasing agents such as MDMA.
- Seizure - This is a rare effect but can happen in a small population of those who are predisposed to them, particularly while in physically taxing conditions such as being dehydrated, undernourished, overheated, or fatigued.
- Colour enhancement - Relative to other psychedelics, this effect may appear to be more saturated.
- Pattern recognition enhancement
- Visual acuity enhancement - This effect typically occurs prominently at lower doses and becomes increasingly suppressed as one raises the dose.
- Drifting (melting, flowing, breathing and morphing) - In comparison to other psychedelics, this effect can be described as highly detailed, realistic, slow and smooth in motion and static in appearance.
- Colour shifting
- Colour tinting
- Visual haze
- After images
- Symmetrical texture repetition
- Perspective distortions
- Depth perception distortions
- Environmental orbism
- Scenery slicing
The visual geometry that is present throughout this experience can be described as more similar in appearance to that of 4-AcO-DMT, ayahuasca and 2C-E than LSD or 2C-B. It can be comprehensively described through its variations as intricate in complexity, abstract in form, organic in feel, structured in organization, brightly lit, and multicoloured in scheme, glossy in shading, soft in its edges, large in size, slow in speed, smooth in motion, rounded in its corners, non-immersive in-depth and consistent in intensity. It has a very "organic" feel and at higher dosages is significantly more likely to result in states of Level 8B visual geometry over level 8A.
Psilocybin and its various other forms produce a full range of high level hallucinatory states in a fashion that is more consistent and reproducible than that of many other commonly used psychedelics. These effects generally include:
- Internal hallucinations (autonomous entities; settings, sceneries, and landscapes; alterations in perspective and scenarios and plots) - This effect is very consistent in dark environments at appropriately high dosages. They can be comprehensively described through their variations as lucid in believability, interactive in style, new experiences in content, autonomous in controllability, geometry-based in style and almost exclusively of a personal, religious, spiritual, science-fiction, fantasy, surreal, nonsensical, or transcendental nature in their overall theme.
- External hallucinations (autonomous entities; settings, sceneries, and landscapes; alterations in perspective and scenarios and plots) - These are more common within dark environments and can be comprehensively described through their variations as lucid in believability, interactive in style, new experiences in content, autonomous in controllability, geometry-based in style and almost exclusively of a personal, religious, spiritual, science-fiction, fantasy, surreal, nonsensical or transcendental nature in their overall theme.
- Object activation
The cognitive effects of psilocybin are described by many as extremely relaxing, profound and stoning in style when compared to other commonly used psychedelics such as LSD or 2C-B which tend to be energetic and stimulating, it is also regarded as being significantly less clearheaded than other commonly used tryptamines such as DMT and ayahuasca. It contains a large number of psychedelic typical and unique cognitive effects.
The most prominent of these typical effects generally include:
- Emotion enhancement - This effect can be described as being more prominent, consistent and profound when compared to other traditional psychedelics such as mescaline or LSD. This can lead to strong feelings of compassion, urgency and even completely sporadic moments of intense emotional significance that can also be periodically affected by enhancement and suppression cycles.
- Empathy, affection, and sociability enhancement - This effect differs from MDMA and other entactogens in that it isn't as central to the experience, feels less forced and more natural and is experienced at a less consistent rate. The sociability enhancement in particular only occurs rarely and it appears to be more emotional.
- Language suppression - This effect can be described as a perceived inability or general unwillingness to talk aloud despite feeling perfectly capable of formulating coherent thoughts within one's internal narrative. It is much more common among inexperienced users.
- Analysis enhancement - This effect is consistent in its manifestation and outrospection dominant.
- Enhancement and suppression cycles - This can be described as constant waves of extremely stimulated and profound thinking which are spontaneously surpassed in a cyclic fashion by waves of general thought suppression and mental intoxication. These two states seem to switch between each other in a consistent loop once every 20 to 60 minutes.
- Feelings of impending doom - This effect is usually only experienced during the come up phase but typically completely passes or subsides once the primary effects begin. It should be noted that this effect is relatively consistent and normal for psilocybin and related tryptamines which is why a positive and well-informed mindset is key. Less regularly this aspect can also occur during the peak but will most often be met afterwards with sensations of euphoria, catharsis or rejuvenation.
- Cognitive euphoria
- Autonomous voice communication
- Conceptual thinking
- Thought connectivity
- Thought deceleration
- Thought loops
- Thought organization
- Confusion - This effect occurs at a higher rate than other psychedelics such as LSD or DMT. It is more commonly observed in users who are inexperienced with psilocybin, or psychedelics in general
- Novelty enhancement
- Creativity enhancement
- Déjà vu
- Increased music appreciation
- Immersion enhancement
- Memory enhancement
- Memory suppression
- Simultaneous emotions
- Personal bias suppression
- Ego replacement - Although this effect is rare and more likely to occur with certain psychedelics like DMT or ayahuasca, it can still spontaneously occur, usually with higher doses.
- Personality regression - Although this effect is rare it can still manifest spontaneously and is thought to depend primarily on the user's set and setting.
- Rejuvenation - While this component can occur spontaneously at any point, it typically follows a difficult phase of the experience, if not the entire experience itself. It is however almost always felt during the offset of a psilocybin experience and tends to slowly transition into the after effects which are generally described as positive. These positive or mindful after effects are sometimes referred to as an "afterglow" and is both common and consistent for psilocybin and related tryptamines.
- Addiction suppression
- Time distortion
- Synaesthesia - In its fullest manifestation, this is a very rare and non-reproducible effect. Increasing the dosage can increase the likelihood of this occurring, but seems to only be a prominent part of the experience among those who are already predisposed to synaesthetic states.
- Dosage independent intensity
- Anecdotally, these components are generally considered to be most consistent with the naturally-occurring entheogenic tryptamines such as ayahuasca, ibogaine and psilocybin. They are listed below as follows:
- Cannabis - When used in conjunction with cannabis, both the visual and cognitive effects of psilocybin can be intensified and extended with great efficiency. This should be used with extreme caution, especially if one is not experienced with psychedelics. This interaction can also amplify the anxiety, confusion and delusion producing aspects of cannabis significantly. The THC and psilocybin synergy is unique in that the severity of its mind-altering qualities can greatly depend on when during the experience the cannabis is taken. Those who choose to use this combination are advised to start off with only a fraction of their usual cannabis dose, and slow down the pace of their normal intake considerably.
- Dissociatives - When used in combination with dissociatives, the geometry, euphoria, dissociation and hallucinatory effects are often greatly enhanced. Dissociative-induced holes, spaces, and voids while under the influence of psilocybin can result in significantly more vivid visuals than dissociatives alone present, along with more intense internal hallucinations, confusion, nausea, delusions and chances of a psychotic reaction.
- MDMA - When used in conjunction with MDMA, the physical and cognitive effects of MDMA are amplified. The visual, physical and cognitive effects of psilocybin are also intensified with an overwhelming euphoric bliss manifested through uniquely pleasurable body highs and headspaces, and uniquely colorful, intricate and majestic visuals. The synergy between these substances is unpredictable, and it is best to start with lower dosages than one would take for both substances individually. It should be noted, however, that the potential toxicity of this combination is unknown.
- Alcohol - This interaction is not typically recommended due to alcohol’s ability to cause dehydration, nausea, and physical fatigue which can negatively affect an experience if taken in moderate to high dosages. This combination is, however, considered to be reasonably safe in low doses and when used responsibly, this can often "take the edge off a trip" as well as dull its psychedelic effects in a fashion somewhat similar to benzodiazepines, albeit in a more physically draining way. With psilocybin mushrooms in particular it is often recommended that the user waits until the "come down" phase if they wish to consume any alcohol due to the sometimes already nauseating and disorienting physical effects of mushrooms, especially within the first 2 - 3 hours of the experience.
- Benzodiazepines - When used in combination with benzodiazepines, benzodiazepines can, depending on the dosage, slightly to completely reduce the intensity of the cognitive, physical and visual effects of a psilocybin trip. They can be very efficient at largely stopping or mitigating a bad trip at the cost of amnesia and reduced trip intensity. Caution is advised when acquiring them for this purpose, however, due to the very high addiction potential that benzodiazepines possess.
- Psychedelics - When used in combination with other psychedelics, each substance's physical, cognitive and visual effects intensify and synergize strongly. The synergy between those substances is unpredictable, and for this reason, is generally not advised. If choosing to combine psychedelics, it is recommended to start with lower dosages than one would take for either substance individually.
There are currently 0 anecdotal reports which describe the effects of this compound within our experience index.
Additional experience reports can be found here:
Biological genera containing psilocybin mushrooms include Copelandia, Galerina, Gymnopilus, Inocybe, Mycena, Panaeolus, Pholiotina, Pluteus, and Psilocybe. Over 100 species are classified in the genus Psilocybe.
Risk of species confusion
As psilocybin mushrooms are capable of being harvested in nature, there is a major risk in misidentifying mushroom species and accidentally consuming poisonous, if not lethal varieties. This can be avoided by educating oneself in advance on how to properly identify the correct species of mushroom and the potential look-alike mushrooms found within one's local area. It is recommended to not learn to do this by oneself, but instead, have someone experienced in mushroom-picking as a mentor.
The dosage of psilocybin mushrooms depends on the potency of the mushroom (the total psilocybin and psilocin content of the mushrooms), which varies significantly both between species and within the same species, but is typically around 0.5–2.0% of the dried weight of the mushroom.
The concentration of active psilocybin mushroom compounds varies not only from species to species, but also from mushroom to mushroom inside a given species, subspecies or variety. The same holds true even for different parts of the same mushroom. In the species Psilocybe samuiensis, the dried cap of the mushroom contains the most psilocybin at about 0.23%–0.90%. The mycelium contains about 0.24%–0.32%.
Psilocybe cubensis (also known as cubes) is one of the most commonly used species of psilocybin mushrooms. The doses for oral consumption for dried cubensis mushrooms are generally considered to be:
- Threshold: 0.25 - 0.50 grams
- Light: 0.5 - 1.5 grams
- Common: 1.5 - 3 grams
- Strong: 3 - 5 grams
- Heavy: 5 grams +
Preparation methods for this compound within our tutorial index include:
- Simple psilocybin mushroom growing technique
- Outdoor mushroom cultivation
- Mushroom chocolates
- Mushroom tea
While further research is needed to establish the utility of psilocybin and other psychedelics in treating depression, a pilot study has observed significantly decreased depression scores in terminal cancer patients six months after treatment with psilocybin. An open-label study was carried out in 2016 in the UK to investigate the feasibility, safety and efficacy of psilocybin in treating patients with unipolar treatment-resistant depression with promising results; although the study was small and involved only twelve patients, seven of those patients met formal criteria for remission one week following psilocybin treatment and five of those were still in remission from their depression at three months.
The mechanism behind this is not known as of yet, but researchers have suggested that psilocin's deactivation of the medial prefrontal cortex (mPFC) may be relevant to its antidepressant effects, as the mPFC is known to be elevated in depression and normalized after effective treatment. mPFC hyperactivity has been associated with trait rumination. Another possible factor to psilocybin's potential against depression may be that depressed patients with high levels of dysfunctional attitudes were found to have low levels of 5-HT(2A) agonism.
Toxicity and harm potential
Psilocybin is non-addictive, is not known to cause brain damage, and has an extremely low toxicity relative to dose. Similar to other psychedelic drugs, there are relatively few physical side effects associated with acute psilocin exposure. Various studies have shown that in reasonable doses in a careful context, it presents little to no negative cognitive, psychiatric or toxic physical consequences.
The toxicity of psilocybin and psilocin is extremely low. In rats, the median lethal dose (LD50) of psilocybin when administered orally is 280 milligrams per kilogram (mg/kg). Psilocybin comprises approximately 1% of the weight of Psilocybe cubensis mushrooms and so nearly 1.7 kilograms (3.7 lb) of dried mushrooms or 17 kilograms (37 lb) of fresh mushrooms would be required for a 60 kilogram (130 lb) person to reach the 280 mg/kg LD50 value of rats. Based on the results of animal studies, the lethal dose of psilocybin has been extrapolated to be 6 grams, 1000 times greater than the effective dose of 6 milligrams.
Despite its lack of physical toxicity, however, it is still strongly recommended that one use harm reduction practices if choosing to use this substance.
Tolerance and addiction potential
Psilocybin is not habit-forming and the desire to use it can actually decrease with use. As with most psychedelics, it is generally considered to have a built-in, self-regulating aspect to it, though cases of dependence and addiction have been documented in the scientific literature. Notably, there it has been claimed that is virtually no withdrawal syndrome when the chronic use of this substance is ceased.
Tolerance to the effects of psilocin are built almost immediately after ingestion. After that, it takes about 3 days for the tolerance to be reduced to half and 7 days to be back at baseline (in the absence of further consumption). Psilocin presents cross-tolerance with all psychedelics, meaning that after the consumption of psilocin all psychedelics will have a reduced effect.
Although many psychoactive substances are safe on their own, they can become dangerous and even life-threatening when combined with other substances. The list below contains some common potentially dangerous combinations, but may not include all of them. Certain combinations may be safe in low doses of each but still increase the potential risk of death. Independent research should always be done to ensure that a combination of two or more substances is safe before consumption.
- Tramadol - Tramadol lowers the seizure threshold and psychedelics may act as triggers for seizures, particularly in those who are predisposed to them.
- Stimulants - Stimulants affect many parts of the brain. Combined with psychedelics, stimulation can turn into uncontrollable anxiety, panic, thought loops and paranoia. This interaction may cause elevated risk of psychosis.
- Lithium - Lithium is often used as treatment for bipolar disorder. It may possibly cause elevated risk of seizures and psychosis due to its glutaminergic and GABAergic effects.
Under international law, the possession and sale of psilocybin (including psilocybin-containing mushrooms and psilocin) is prohibited in most countries.
- Austria: Psilocybin and psilocin containing mushrooms are illegal to possess, produce and sell under the SMG (Suchtmittelgesetz Österreich).
- Brazil: Possession, production and sale is illegal as it is listed on Portaria SVS/MS nº 344, but mushrooms fall under religious use laws.
- British Virgin Isles: The sale of mushrooms is illegal, but possession and consumption is legal.
- Bulgaria: The sale of mushrooms is illegal, but possession and consumption is legal.
- Belgium: Possession and sale of mushrooms have been illegal since 1988.
- Canada: Psilocybin and psilocin are illegal to possess, obtain or produce without a prescription or license as they are Schedule III under the Controlled Drugs and Substances Act.
- Czech Republic: The distribution (including sale) of mushrooms is illegal, but consumption is legal. The possession of over 40 hallucinogenic caps is considered a crime if they contain more than 50mg of psilocin or the corresponding amount of psilocybin. The possession of more than 40g of hallucinogenic mycelium is considered a crime. If these limits are not exceeded, the act is considered a minor offense and a fine of up to 15 thousand CZK may be imposed.
- Cyprus The possession, sale and consumption of mushrooms is illegal.
- Denmark: The possession, growth, sale and consumption of mushrooms is illegal.
- Finland: The possession, growth, sale and consumption of mushrooms is illegal.
- Germany: The possession, growth, sale and consumption of mushrooms is illegal.
- Greece: The possession, growth, sale and consumption of mushrooms is illegal.
- Ireland: The possession, growth, sale and consumption of mushrooms is illegal.
- Japan: The possession, growth, sale and consumption of mushrooms is illegal.
- Latvia: Hallucinogenic mushrooms, psilocin and psilocybin are Schedule I controlled substances.
- Mexico: The possession, growth, sale and consumption of mushrooms is illegal. Rules are relaxed regarding religious use however.
- The Netherlands: The possession, growth, sale and consumption of mushrooms is illegal. However, due to a legal loophole, psilocybin truffles can be legally possessed, grown, sold and consumed.
- New Zealand: Psilocybin is Class A.
- Norway: Possession, growth, sale and consumption of mushrooms is illegal. Spores, even though not containing psilocybin, are also illegal.
- Turkey: The possession, growth, sale and consumption of mushrooms is illegal.
- United Kingdom: According to the 2005 Drugs Act, fresh and prepared psilocybin mushrooms are Class A.
- United States: Psilocybin and psilocin are illegal Schedule I drugs.
- Psilocybin mushrooms (Wikipedia)
- Psilocybin mushrooms (Erowid Vault)
- World Wide Distribution of Magic Mushrooms
- The Big & Dandy Psilocybin Mushrooms Thread (Bluelight)
- Psilocybin mushrooms, broken down and described (Disregard Everything I Say)
- Passie, Torsten, et al. The Pharmacology of Psilocybin. Addiction Biology 7.4 (2002): 357-364. https://doi.org/10.1080/1355621021000005937
- Tylš, F., Páleníček, T., & Horáček, J. (2014). Psilocybin–summary of knowledge and new perspectives. European Neuropsychopharmacology, 24(3), 342-356. http://doi.org/10.1016/j.euroneuro.2013.12.006.
- Vollenweider, F. X., & Kometer, M. (2010). The neurobiology of psychedelic drugs: implications for the treatment of mood disorders. Nature Publishing Group, 11(9), 642–651. https://doi.org/10.1038/nrn2884
- Nichols, D. E. (2016). Psychedelics, (April), 264–355. https://doi.org/10.1124/pr.115.011478
- Lüscher, C., & Ungless, M. A. (2006). The Mechanistic Classification of Addictive Drugs, 3(11). https://doi.org/10.1371/journal.pmed.0030437
- Strassman, R. J. (1984). Adverse Reactions to Psychedelic Drugs: A Review of the Literature. The Journal of Nervous and Mental Disease, 172(10), 577-595. PMID: 6384428
- The oldest Representations of Hallucinogenic Mushrooms in the World | http://www.shroomery.org/6228/The-oldest-Representations-of-Hallucinogenic-Mushrooms-in-the-World
- Horita, A., & Weber, L. J. (1961). Dephosphorylation of psilocybin to psilocin by alkaline phosphatase. Proceedings of the Society for Experimental Biology and Medicine, 106(1), 32-34.
- Petri, G., Expert, P., Turkheimer, F., Nutt, D., Hellyer, P. J., & Vaccarino, F. (2014). Homological scaffolds of brain functional networks, 14–18. https://doi.org/10.1098/rsif.2014.0873
- Psilocybin Investigator’s Brochure | http://www.maps.org/research/psilo/psilo_ib.pdf
- Johnson, M. W., Garcia-Romeu, A., Cosimano, M. P., & Griffiths, R. R. (2014). Pilot study of the 5-HT2AR agonist psilocybin in the treatment of tobacco addiction. Journal of Psychopharmacology, 28(11), 983-992. https://doi.org/10.1177/0269881114548296
- Gartz J, Allen JW, Merlin MD (2004). "Ethnomycology, biochemistry, and cultivation of Psilocybe samuiensis Guzmán, Bandala and Allen, a new psychoactive fungus from Koh Samui, Thailand". Journal of Ethnopharmacology. 43 (2): 73–80. PMID 7967658. https://doi.org/10.1016/0378-8741(94)90006-X.
- Grob, C. S., Danforth, A. L., Chopra, G. S., Hagerty, M., McKay, C. R., Halberstadt, A. L., & Greer, G. R. (2011). Pilot study of psilocybin treatment for anxiety in patients with advanced-stage cancer. Archives of General Psychiatry, 68(1), 71-78. https://doi.org/10.1001/archgenpsychiatry.2010.116
- Carhart-Harris, R. L., Bolstridge, M., Rucker, J., Day, C. M., Erritzoe, D., Kaelen, M., ... & Taylor, D. (2016). Psilocybin with psychological support for treatment-resistant depression: an open-label feasibility study. The Lancet Psychiatry, 3(7), 619-627. https://doi.org/10.1016/S2215-0366(16)30065
- Carhart-Harris, R. L., Erritzoe, D., Williams, T., Stone, J. M., Reed, L. J., Colasanti, A., ... & Hobden, P. (2012). Neural correlates of the psychedelic state as determined by fMRI studies with psilocybin. Proceedings of the National Academy of Sciences, 109(6), 2138-2143. https://doi.org/10.1073/pnas.1119598109
- Farb, N. A. S., Anderson, A. K., Bloch, R. T., & Segal, Z. V. (2011). Mood Linked Responses in Medial Prefrontal Cortex Predict Relapse in Patients with Recurrent Unipolar Depression. Biological Psychiatry, 70(4), 366–372. https://doi.org/10.1016/j.biopsych.2011.03.009
- Bhagwagar, Z., Hinz, R., Taylor, M., Fancy, S., Cowen, P., & Grasby, P. (2006). Increased 5-HT 2A receptor binding in euthymic, medication-free patients recovered from depression: a positron emission study with [11 C] MDL 100,907. American Journal of Psychiatry, 163(9), 1580-1587. http://dx.doi.org/10.1176/ajp.2006.163.9.1580
- Meyer, J. H., McMain, S., Kennedy, S. H., Korman, L., Brown, G. M., DaSilva, J. N., ... & Houle, S. (2003). Dysfunctional attitudes and 5-HT2 receptors during depression and self-harm. American Journal of Psychiatry, 160(1), 90-99. https://www.doi.org/10.1176/appi.ajp.160.1.90
- Development of a rational scale to assess the harm of drugs of potential misuse (ScienceDirect) | http://www.sciencedirect.com/science/article/pii/S0140673607604644
- Diaz, Jaime (1996). How Drugs Influence Behavior: A Neurobehavioral Approach. Englewood Cliffs: Prentice Hall. ISBN 9780023287640
- Talaie, H., Panahandeh, R., Fayaznouri, M. R., Asadi, Z., & Abdollahi, M. (2009). Dose-independent occurrence of seizure with tramadol. Journal of medical toxicology, 5(2), 63-67. doi:10.1007/BF03161089
- Controlled Drugs and Substances Act of Canada
- Noteikumi par Latvijā kontrolējamajām narkotiskajām vielām, psihotropajām vielām un prekursoriem (I saraksts) | http://likumi.lv/doc.php?id=121086
- Legislation - Drugs Act 2005| http://www.legislation.gov.uk/ukpga/2005/17/contents
- FDA - Controlled Substances Act| http://www.fda.gov/regulatoryinformation/legislation/ucm148726.htm