Psilocybe cubensis, a widely recognized psychoactive mushroom species, has played a significant role in both historical and modern therapeutic practices. This review explores the complex interplay between genetic diversity, strain variability and environmental factors that shape the biosynthesis of key psychoactive compounds, including psilocybin and psilocin. With many strains exhibiting substantial variability in their phenotypic characteristics and biochemical content, understanding and documenting this diversity is crucial for optimizing therapeutic applications. The review also highlights advances in cultivation techniques, such as submerged fermentation of the mycelium, and innovative analytical methodologies that have improved the precision of compound quantification and extraction. Although there is limited scientific information on P. cubensis due to nearly four decades of regulatory restrictions on psychedelic research, recent developments in genetic and biochemical studies are beginning to provide valuable insights into its therapeutic potential. Furthermore, this review emphasizes key knowledge gaps and offers insights into future research directions to advance the cultivation, scientific documentation of strain diversity, regulatory considerations and therapeutic use of P. cubensis.

• Keywords
• Psilocybe, fungi, genetics, mushroom, mycelium, psilocin, psilocybin, psychoactive,
• Publication type
• Journal Article MeSH
• Review MeSH

Since not only psilocybin (PSB) but also PSB-containing mushrooms are used for psychedelic therapy and microdosing, it is necessary to know their concentration variability in wild-grown mushrooms. This article aimed to determine the PSB, psilocin (PS), baeocystin (BA), norbaeocystin (NB), and aeruginascin (AE) concentrations in a large sample set of mushrooms belonging to genera previously reported to contain psychotropic tryptamines. Ultra-high performance liquid chromatography coupled with tandem mass spectrometry was used to quantify tryptamine alkaloids in the mushroom samples. Most mushroom collections were documented by fungarium specimens and/or ITS rDNA/LSU/EF1-α sequencing. Concentrations of five tryptamine alkaloids were determined in a large sample set of 226 fruiting bodies of 82 individual collections from seven mushroom genera. For many mushroom species, concentrations of BA, NB, and AE are reported for the first time. The highest PSB/PS concentrations were found in Psilocybe species, but no tryptamines were detected in the P. fuscofulva and P. fimetaria collections. The tryptamine concentrations in mushrooms are extremely variable, representing a problem for mushroom consumers due to the apparent risk of overdose. The varied cocktail of tryptamines in wild mushrooms could influence the medicinal effect compared to therapy with chemically pure PSB, posing a serious problem for data interpretation.

• Keywords
• Psilocybe, baeocystin, hallucinogenic fungi, psilocin, psilocybin,
• MeSH
• Agaricales * genetics   chemistry   MeSH
• Alkaloids * analysis   MeSH
• Tryptamines MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Alkaloids * MeSH
• baeocystin MeSH Browser
• N, N, N-trimethyl-4-phosphoryloxytryptamine MeSH Browser
• tryptamine MeSH Browser
• Tryptamines MeSH

RATIONALE: Serotonergic psychedelics are being studied as novel treatments for mental health disorders and as facilitators of improved well-being, mental function, and creativity. Recent studies have found mixed results concerning the effects of low doses of psychedelics ("microdosing") on these domains. However, microdosing is generally investigated using instruments designed to assess larger doses of psychedelics, which might lack sensitivity and specificity for this purpose. OBJECTIVES: Determine whether unconstrained speech contains signatures capable of identifying the acute effects of psilocybin microdoses. METHODS: Natural speech under psilocybin microdoses (0.5 g of psilocybin mushrooms) was acquired from thirty-four healthy adult volunteers (11 females: 32.09 ± 3.53 years; 23 males: 30.87 ± 4.64 years) following a double-blind and placebo-controlled experimental design with two measurement weeks per participant. On Wednesdays and Fridays of each week, participants consumed either the active dose (psilocybin) or the placebo (edible mushrooms). Features of interest were defined based on variables known to be affected by higher doses: verbosity, semantic variability, and sentiment scores. Machine learning models were used to discriminate between conditions. Classifiers were trained and tested using stratified cross-validation to compute the AUC and p-values. RESULTS: Except for semantic variability, these metrics presented significant differences between a typical active microdose and the inactive placebo condition. Machine learning classifiers were capable of distinguishing between conditions with high accuracy (AUC [Formula: see text] 0.8). CONCLUSIONS: These results constitute first evidence that low doses of serotonergic psychedelics can be identified from unconstrained natural speech, with potential for widely applicable, affordable, and ecologically valid monitoring of microdosing schedules.

• Keywords
• Language, Machine learning, Microdosing, Psilocybin, Psychedelics,
• MeSH
• Adult MeSH
• Mental Disorders * MeSH
• Double-Blind Method MeSH
• Hallucinogens * pharmacology   MeSH
• Language MeSH
• Creativity MeSH
• Humans MeSH
• Psilocybin pharmacology   MeSH
• Check Tag
• Adult MeSH
• Humans MeSH
• Male MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Hallucinogens * MeSH
• Psilocybin MeSH

The use of low sub-perceptual doses of psychedelics ("microdosing") has gained popularity in recent years. Although anecdotal reports claim multiple benefits associated with this practice, the lack of placebo-controlled studies severely limits our knowledge of microdosing and its effects. Moreover, research conducted in standard laboratory settings could fail to capture the motivation of individuals engaged or planning to engage in microdosing protocols, thus underestimating the likelihood of positive effects on creativity and cognitive function. We recruited 34 individuals starting to microdose with psilocybin mushrooms (Psilocybe cubensis), one of the materials most frequently used for this purpose. Following a double-blind placebo-controlled experimental design, we investigated the acute and short-term effects of 0.5 g of dried mushrooms on subjective experience, behavior, creativity (divergent and convergent thinking), perception, cognition, and brain activity. The reported acute effects were significantly more intense for the active dose compared to the placebo, but only for participants who correctly identified their experimental condition. These changes were accompanied by reduced EEG power in the theta band, together with preserved levels of Lempel-Ziv broadband signal complexity. For all other measurements there was no effect of microdosing except for few small changes towards cognitive impairment. According to our findings, low doses of psilocybin mushrooms can result in noticeable subjective effects and altered EEG rhythms, but without evidence to support enhanced well-being, creativity and cognitive function. We conclude that expectation underlies at least some of the anecdotal benefits attributed to microdosing with psilocybin mushrooms.

• MeSH
• Agaricales * MeSH
• Double-Blind Method MeSH
• Hallucinogens * pharmacology   MeSH
• Humans MeSH
• Motivation MeSH
• Psilocybin pharmacology   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Randomized Controlled Trial MeSH
• Names of Substances
• Hallucinogens * MeSH
• Psilocybin MeSH