N, N-Dimethyltryptamine (DMT), an Endogenous Hallucinogen: Past, Present, and Future Research to Determine Its Role and Function

Neurobiological research on N,N-dimethyltryptamine (DMT) and its potentiation by monoamine oxidase (MAO) inhibition: from ayahuasca to synthetic combinations of DMT and MAO inhibitors

The potent hallucinogen N,N-dimethyltryptamine (DMT) has garnered significant interest in recent years due to its profound effects on consciousness and its therapeutic psychopotential. DMT is an integral (but not exclusive) psychoactive alkaloid in the Amazonian plant-based brew ayahuasca, in which admixture of several β-carboline monoamine oxidase A (MAO-A) inhibitors potentiate the activity of oral DMT, while possibly contributing in other respects to the complex psychopharmacology of ayahuasca. Irrespective of the route of administration, DMT alters perception, mood, and cognition, presumably through agonism at serotonin (5-HT) 1A/2A/2C receptors in brain, with additional actions at other receptor types possibly contributing to its overall psychoactive effects. Due to rapid first pass metabolism, DMT is nearly inactive orally, but co-administration with β-carbolines or synthetic MAO-A inhibitors (MAOIs) greatly increase its bioavailability and duration of action. The synergistic effects of DMT and MAOIs in ayahuasca or synthetic formulations may promote neuroplasticity, which presumably underlies their promising therapeutic efficacy in clinical trials for neuropsychiatric disorders, including depression, addiction, and post-traumatic stress disorder. Advances in neuroimaging techniques are elucidating the neural correlates of DMT-induced altered states of consciousness, revealing alterations in brain activity, functional connectivity, and network dynamics. In this comprehensive narrative review, we present a synthesis of current knowledge on the pharmacology and neuroscience of DMT, β-carbolines, and ayahuasca, which should inform future research aiming to harness their full therapeutic potential.

Phase 1, placebo-controlled, single ascending dose trial to evaluate the safety, pharmacokinetics and effect on altered states of consciousness of intranasal BPL-003 (5-methoxy-N,N-dimethyltryptamine benzoate) in healthy participants

AIMS

To investigate the safety, tolerability, pharmacokinetics (PK) and pharmacodynamics (PD) of BPL-003, a novel intranasal benzoate salt formulation of 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT), in healthy participants.

METHODS

In all, 44 psychedelic-naïve participants enrolled in the double-blind, placebo-controlled single ascending dose study (1-12 mg BPL-003). Concentrations of 5-MeO-DMT and its pharmacologically active metabolite, bufotenine, were determined in plasma and urine. PD endpoints included subjective drug intensity (SDI) rating, the Mystical Experience Questionnaire (MEQ-30) and the Ego Dissolution Inventory (EDI).

RESULTS

BPL-003 was well tolerated at doses up to 12 mg. There were no serious adverse events (AEs), and most AEs were mild; the most common being nasal discomfort, nausea, headache and vomiting. 5-MeO-DMT was rapidly absorbed and eliminated; the median time to peak plasma concentration was approximately 8-10 min and the mean terminal elimination half-life was <27 min. 5-MeO-DMT systemic exposure increased approximately dose-proportionally, while plasma bufotenine concentrations and urinary excretion of 5-MeO-DMT and bufotenine were negligible. The intensity of the SDI ratings was associated with plasma 5-MeO-DMT concentrations. MEQ-30 and EDI scores generally increased with the BPL-003 dose; 60% of participants had a 'complete mystical experience' at 10 and 12 mg doses. Profound and highly emotional consciousness-altering effects were observed with BPL-003, with a rapid onset and short-lasting duration.

CONCLUSION

The novel intranasal formulation of BPL-003 was well tolerated with dose-proportional increases in PK and PD effects. The short duration of action and induction of mystical experiences suggest clinical potential, warranting further trials.

CLINICAL TRIAL REGISTRATION

NCT05347849.

Novel Thermosensitive and Mucoadhesive Nasal Hydrogel Containing 5-MeO-DMT Optimized Using Box-Behnken Experimental Design

We present the development and characterization of a nasal drug delivery system comprised of a thermosensitive mucoadhesive hydrogel based on a mixture of the polymers Poloxamer 407, Poloxamer 188 and Hydroxypropyl-methylcellulose, and the psychedelic drug 5-methoxy-N,-N-dimethyltryptamine. The development relied on a 3 × 3 Box-Behnken experimental design, focusing on optimizing gelification temperature, viscosity and mucoadhesion. The primary objective of this work was to tailor the formulation for efficient nasal drug delivery. This would increase contact time between the hydrogel and the mucosa while preserving normal ciliary functioning. Following optimization, the final formulation underwent characterization through an examination of the in vitro drug release profile via dialysis under sink conditions. Additionally, homogeneity of its composition was assessed using Raman Confocal Spectroscopy. The results demonstrate complete mixing of drug and polymers within the hydrogel matrix. Furthermore, the formulation exhibits sustained release profile, with 73.76% of the drug being delivered after 5 h in vitro. This will enable future studies to assess the possibility of using this formulation to treat certain mental disorders. We have successfully developed a promising thermosensitive and mucoadhesive hydrogel with a gelling temperature of around 32 °C, a viscosity close to 100 mPas and a mucoadhesion of nearly 4.20 N·m.

"Immunohistochemical analysis of Sigma-1 receptor (σ-1R) expression in human pineal gland in relation to different causes of death"

Sigma-1 receptor (σ-1R) modulates cellular signaling pathways, probably acting as a ligand operated chaperone. When activated, the receptor translocates from the interface mitochondrion associated membrane of the endoplasmic reticulum to the cell membrane. σ-1R was demonstrated in some brain regions, including the pineal gland, and was proposed to be involved in several cerebral processes, including neuroprotective responses against homeostasis alterations. On this basis, the immunohistochemical expression of σ-1R in human pineal glands was evaluated, with particular regard to the different causes of death. Thirty-eight pineal glands obtained from forensic autopsies were divided into five groups according to the cause of death: sudden death, drowning, fire fatality, hanging, and hemorrhagic shock, and examined with hematoxylin-eosin stain and immunohistochemistry for σ-1R. Both pinealocytes and perivascular spaces were evaluated. The pineal glands from sudden death were only mildly positive for σ-1R, while a more evident immunopositivity was observed in hanging, fire fatality, hemorrhagic shock, and drowning. These results were confirmed in a two-by-two comparison between the sudden death group and other groups. Our data demonstrate for the first time with immunohistochemical techniques the presence of σ-1R expression in the human pineal gland and propose a direct correlation between σ-1R expression and duration of the death process, in particular when hypoxic conditions and/or excessive psychological stress are present.

Efficacy and safety of psychedelics for the treatment of mental disorders: A systematic review and meta-analysis

We aim to systematically review and meta-analyze the effectiveness and safety of psychedelics [psilocybin, ayahuasca (active component DMT), LSD and MDMA] in treating symptoms of various mental disorders. Web of Science, Embase, EBSCO, and PubMed were searched up to February 2024 and 126 articles were finally included. Results showed that psilocybin has the largest number of articles on treating mood disorders (N = 28), followed by ayahuasca (N = 7) and LSD (N = 6). Overall, psychedelics have therapeutic effects on mental disorders such as depression and anxiety. Specifically, psilocybin (Hedges' g = -1.49, 95% CI [-1.67, -1.30]) showed the strongest therapeutic effect among four psychedelics, followed by ayahuasca (Hedges' g = -1.34, 95% CI [-1.86, -0.82]), MDMA (Hedges' g = -0.83, 95% CI [-1.33, -0.32]), and LSD (Hedges' g = -0.65, 95% CI [-1.03, -0.27]). A small amount of evidence also supports psychedelics improving tobacco addiction, eating disorders, sleep disorders, borderline personality disorder, obsessive-compulsive disorder, and body dysmorphic disorder. The most common adverse event with psychedelics was headache. Nearly a third of the articles reported that no participants reported lasting adverse effects. Our analyses suggest that psychedelics reduce negative mood, and have potential efficacy in other mental disorders, such as substance-use disorders and PTSD.

N, N-Dimethyltryptamine, a natural hallucinogen, ameliorates Alzheimer's disease by restoring neuronal Sigma-1 receptor-mediated endoplasmic reticulum-mitochondria crosstalk

BACKGROUND

Aberrant neuronal Sigma-1 receptor (Sig-1r)-mediated endoplasmic reticulum (ER)- mitochondria signaling plays a key role in the neuronal cytopathology of Alzheimer's disease (AD). The natural psychedelic N, N-dimethyltryptamine (DMT) is a Sig-1r agonist that may have the anti-AD potential through protecting neuronal ER-mitochondrial interplay.

METHODS

3×TG-AD transgenic mice were administered with chronic DMT (2 mg/kg) for 3 weeks and then performed water maze test. The Aβ accumulation in the mice brain were determined. The Sig-1r level upon DMT treatment was tested. The effect of DMT on the ER-mitochondrial contacts site and multiple mitochondria-associated membrane (MAM)-associated proteins were examined. The effect of DMT on calcium transport between ER and mitochondria and the mitochondrial function were also evaluated.

RESULTS

chronic DMT (2 mg/kg) markedly alleviated cognitive impairment of 3×TG-AD mice. In parallel, it largely diminished Aβ accumulation in the hippocampus and prefrontal cortex. DMT restored the decreased Sig-1r levels of 3×TG-AD transgenic mice. The hallucinogen reinstated the expression of multiple MAM-associated proteins in the brain of 3×TG-AD mice. DMT also prevented physical contact and calcium dynamic between the two organelles in in vitro and in vivo pathological circumstances. DMT modulated oxidative phosphorylation (OXPHOS) and ATP synthase in the in vitro model of AD.

CONCLUSION

The anti-AD effects of DMT are associated with its protection of neuronal ER-mitochondria crosstalk via the activation of Sig-1r. DMT has the potential to serve as a novel preventive and therapeutic agent against AD.

Psychedelic Therapy: A Primer for Primary Care Clinicians-N,N-Dimethyltryptamine and Ayahuasca

BACKGROUND

N,N-dimethyltryptamine (DMT) is a naturally occurring serotonergic psychedelic found in natural plants around the globe. As the main psychoactive component in ayahuasca, which also contains monoamine oxidase inhibitors, DMT has been consumed as plant-based brew by indigenous peoples for centuries. Further research is required to delineate the therapeutic utility of DMT.

AREAS OF UNCERTAINTY

Although previous research has shown that DMT is synthesized endogenously, it may not be produced at physiologically relevant concentrations. Additionally, the phenomenological similarities between the DMT-induced state and near-death experiences led to the popular hypothesis that endogenous DMT is released during the dying process. However, this hypothesis continues to be debated. Generally, DMT and ayahuasca seem to be physiologically and psychiatrically safe, although ayahuasca is known to cause transient vomiting.

THERAPEUTIC ADVANCES

A double-blind, randomized controlled trial showed that, within 1 week, ayahuasca causes remission in 36% of patients with treatment-resistant depression. According to top-line results from a recent phase IIa trial, 57% of patients with major depressive disorder experienced remission 12 weeks after receiving a single intravenous dose of DMT.

LIMITATIONS

There has only been a single published double-blind randomized controlled trial on ayahuasca and 2 on DMT. All clinical trials have had small sample sizes (≤34 participants). DMT requires further research to understand its therapeutic and clinical potential as a psychedelic.

CONCLUSIONS

Preliminary evidence indicates that ayahuasca and DMT may be more effective than existing antidepressants for treating major depressive disorder and treatment-resistant depression.

Safety and tolerability of inhaled N,N-Dimethyltryptamine (BMND01 candidate): A phase I clinical trial

Psychedelics are being increasingly examined for their therapeutic potential in mood disorders. While the acute effects of ayahuasca, psilocybin, and lysergic acid diethylamide (LSD) last over several hours, inhaled N,N-Dimethyltryptamine (DMT) effects last around 10 min, which might provide a cost- and time-effective alternative to the clinical application of oral psychedelics. We aimed at investigating the safety and tolerability of inhaled DMT (BMND01 candidate). We recruited 27 healthy volunteers to receive a first, lower dose and a second, higher dose (5/20 mg, 7.5/30 mg, 10/40 mg, 12.5/50 mg, or 15/60 mg) of inhaled DMT in an open-label, single-ascending, fixed-order, dose-response study design. We investigated subjective experiences (intensity, valence, and phenomenology), physiological effects (blood pressure, heart rate, respiratory rate, blood oxygen saturation, body temperature), biochemical markers (liver, kidney, and metabolic functions), and adverse events during the acute and post-acute effects of DMT. DMT dose-dependently increased intensity, valence and perceptual ratings. There was a mild, transient, and self-limited increase in blood pressure and heart rate. There were no changes in safety blood biomarkers and no serious adverse events. DMT dose-dependently enhanced subjective experiences and positive valence. Inhaled DMT might be an efficient, non-invasive, safe route of administration, which might simplify the clinical use of this substance. This is the first clinical trial to test the effects of inhaled DMT (BMND01 candidate).

Effect of chemically synthesized psilocybin and psychedelic mushroom extract on molecular and metabolic profiles in mouse brain

Psilocybin, a naturally occurring, tryptamine alkaloid prodrug, is currently being investigated for the treatment of a range of psychiatric disorders. Preclinical reports suggest that the biological effects of psilocybin-containing mushroom extract or "full spectrum" (psychedelic) mushroom extract (PME), may differ from those of chemically synthesized psilocybin (PSIL). We compared the effects of PME to those of PSIL on the head twitch response (HTR), neuroplasticity-related synaptic proteins and frontal cortex metabolomic profiles in male C57Bl/6j mice. HTR measurement showed similar effects of PSIL and PME over 20 min. Brain specimens (frontal cortex, hippocampus, amygdala, striatum) were assayed for the synaptic proteins, GAP43, PSD95, synaptophysin and SV2A, using western blots. These proteins may serve as indicators of synaptic plasticity. Three days after treatment, there was minimal increase in synaptic proteins. After 11 days, PSIL and PME significantly increased GAP43 in the frontal cortex (p = 0.019; p = 0.039 respectively) and hippocampus (p = 0.015; p = 0.027) and synaptophysin in the hippocampus (p = 0.041; p = 0.05) and amygdala (p = 0.035; p = 0.004). PSIL increased SV2A in the amygdala (p = 0.036) and PME did so in the hippocampus (p = 0.014). In the striatum, synaptophysin was increased by PME only (p = 0.023). There were no significant effects of PSIL or PME on PSD95 in any brain area when these were analyzed separately. Nested analysis of variance (ANOVA) showed a significant increase in each of the 4 proteins over all brain areas for PME versus vehicle control, while significant PSIL effects were observed only in the hippocampus and amygdala and were limited to PSD95 and SV2A. Metabolomic analyses of the pre-frontal cortex were performed by untargeted polar metabolomics utilizing capillary electrophoresis - Fourier transform mass spectrometry (CE-FTMS) and showed a differential metabolic separation between PME and vehicle groups. The purines guanosine, hypoxanthine and inosine, associated with oxidative stress and energy production pathways, showed a progressive decline from VEH to PSIL to PME. In conclusion, our synaptic protein findings suggest that PME has a more potent and prolonged effect on synaptic plasticity than PSIL. Our metabolomics data support a gradient of effects from inert vehicle via chemical psilocybin to PME further supporting differential effects. Further studies are needed to confirm and extend these findings and to identify the molecules that may be responsible for the enhanced effects of PME as compared to psilocybin alone.

Hypothetical biosynthetic pathways of pharmaceutically potential hallucinogenic metabolites in Myristicaceae, mechanistic convergence and co-evolutionary trends in plants and humans

The family Myristicaceae harbour mind-altering phenylpropanoids like myristicin, elemicin, safrole, tryptamine derivatives such as N,N-dimethyltryptamine (DMT) and 5-methoxy N,N-dimethyltryptamine (5-MeO-DMT) and β-carbolines such as 1-methyl-6-methoxy-dihydro-β-carboline and 2-methyl-6-methoxy-1,2,3,4-tetrahydro-β-carboline. This study aimed to systematically review and propose the hypothetical biosynthetic pathways of hallucinogenic metabolites of Myristicaceae which have the potential to be used pharmaceutically. Relevant publications were retrieved from online databases, including Google Scholar, PubMed Central, Science Direct and the distribution of the hallucinogens among the family was compiled. The review revealed that the biosynthesis of serotonin in plants was catalysed by tryptamine 5-hydroxylase (T5H) and tryptophan 5-hydroxylase (TPH), whereas in invertebrates and vertebrates only by tryptophan 5-hydroxylase (TPH). Indolethylamine-N-methyltransferase catalyses the biosynthesis of DMT in plants and the brains of humans and other mammals. Caffeic acid 3-O-methyltransferase catalyses the biosynthesis of both phenylpropanoids and tryptamines in plants. All the hallucinogenic markers exhibited neuropsychiatric effects in humans as mechanistic convergence. The review noted that DMT, 5-MeO-DMT, and β-carbolines were natural protectants against both plant stress and neurodegenerative human ailments. The protein sequence data of tryptophan 5-hydroxylase and tryptamine 5-hydroxylase retrieved from NCBI showed a co-evolutionary relationship in between animals and plants on the phylogenetic framework of a Maximum Parsimony tree. The review also demonstrates that the biosynthesis of serotonin, DMT, 5-MeO-DMT, 5-hydroxy dimethyltryptamine, and β-carbolines in plants, as well as endogenous secretion of these compounds in the brain and blood of humans and rodents, reflects co-evolutionary mutualism in plants and humans.

The Psychedelic Future of Post-Traumatic Stress Disorder Treatment

Post-traumatic stress disorder (PTSD) is a mental health condition that can occur following exposure to a traumatic experience. An estimated 12 million U.S. adults are presently affected by this disorder. Current treatments include psychological therapies (e.g., exposure-based interventions) and pharmacological treatments (e.g., selective serotonin reuptake inhibitors (SSRIs)). However, a significant proportion of patients receiving standard-of-care therapies for PTSD remain symptomatic, and new approaches for this and other trauma-related mental health conditions are greatly needed. Psychedelic compounds that alter cognition, perception, and mood are currently being examined for their efficacy in treating PTSD despite their current status as Drug Enforcement Administration (DEA)- scheduled substances. Initial clinical trials have demonstrated the potential value of psychedelicassisted therapy to treat PTSD and other psychiatric disorders. In this comprehensive review, we summarize the state of the science of PTSD clinical care, including current treatments and their shortcomings. We review clinical studies of psychedelic interventions to treat PTSD, trauma-related disorders, and common comorbidities. The classic psychedelics psilocybin, lysergic acid diethylamide (LSD), and N,N-dimethyltryptamine (DMT) and DMT-containing ayahuasca, as well as the entactogen 3,4-methylenedioxymethamphetamine (MDMA) and the dissociative anesthetic ketamine, are reviewed. For each drug, we present the history of use, psychological and somatic effects, pharmacology, and safety profile. The rationale and proposed mechanisms for use in treating PTSD and traumarelated disorders are discussed. This review concludes with an in-depth consideration of future directions for the psychiatric applications of psychedelics to maximize therapeutic benefit and minimize risk in individuals and communities impacted by trauma-related conditions.

A mechanistic insight for the biosynthesis of N,N-dimethyltryptamine: An ONIOM theoretical approach

Psychoactive natural products are potent serotonergic agonists capable of modulating brain functions such as memory and cognition. These substances have shown therapeutic potential for treating various mental disorders. The fact that N,N-dimethyltryptamine (DMT) is produced endogenously in several plants and animals, including humans, makes it particularly attractive. As an amino acid-derived alkaloid, the DMT biosynthetic pathway is part of the L-tryptophan biochemical cascade and can be divided into the decarboxylation by an aromatic L-amino acid decarboxylase (AADC) for tryptamine formation and the subsequent double-methylation by the indolethylamine-N-methyltransferase (INMT) through the cofactor S-adenosyl-L-methionine (SAM), a methyl donor. Unlike the decarboxylation mechanism of L-tryptophan, the molecular details of the double methylation of tryptamine have not been elucidated. Therefore, we propose an in silico model using molecular dynamics (MD), non-covalent interaction index (NCI) and density functional theory (DFT) calculations with the ONIOM QM:MM B3LYP/6-31+G(d,p):MM/UFF level of theory. Based on the obtained energetic data, the potential energy surface (PES) indicates an SN2 mechanism profile, with the second methylation energy barrier being the rate-limiting step with δG‡=60kJ∙mol-1 larger than the previous methylation, following the NCI analysis showing more repulsive interactions for the second transition state. In addition, the hybridization information of each reaction step provides geometric details about the double-methylation.

A pilot study of cerebral metabolism and serotonin 5-HT2A receptor occupancy in rats treated with the psychedelic tryptamine DMT in conjunction with the MAO inhibitor harmine

Rationale: The psychedelic effects of the traditional Amazonian botanical decoction known as ayahuasca are often attributed to agonism at brain serotonin 5-HT2A receptors by N,N-dimethyltryptamine (DMT). To reduce first pass metabolism of oral DMT, ayahuasca preparations additionally contain reversible monoamine oxidase A (MAO-A) inhibitors, namely β-carboline alkaloids such as harmine. However, there is lacking biochemical evidence to substantiate this pharmacokinetic potentiation of DMT in brain via systemic MAO-A inhibition. Objectives: We measured the pharmacokinetic profile of harmine and/or DMT in rat brain, and tested for pharmacodynamic effects on brain glucose metabolism and DMT occupancy at brain serotonin 5-HT2A receptors. Methods: We first measured brain concentrations of harmine and DMT after treatment with harmine and/or DMT at low sub-cutaneous doses (1 mg/kg each) or harmine plus DMT at moderate doses (3 mg/kg each). In the same groups of rats, we also measured ex vivo the effects of these treatments on the availability of serotonin 5-HT2A receptors in frontal cortex. Finally, we explored effects of DMT and/or harmine (1 mg/kg each) on brain glucose metabolism with [18F]FDG-PET. Results: Results confirmed that co-administration of harmine inhibited the formation of the DMT metabolite indole-3-acetic acid (3-IAA) in brain, while correspondingly increasing the cerebral availability of DMT. However, we were unable to detect any significant occupancy by DMT at 5-HT2A receptors measured ex vivo, despite brain DMT concentrations as high as 11.3 µM. We did not observe significant effects of low dose DMT and/or harmine on cerebral [18F]FDG-PET uptake. Conclusion: These preliminary results call for further experiments to establish the dose-dependent effects of harmine/DMT on serotonin receptor occupancy and cerebral metabolism.

Discovery and In Vitro Characterization of SPL028: Deuterated N,N-Dimethyltryptamine

The psychedelic N,N- dimethyltryptamine (DMT) is in clinical development for the treatment of major depressive disorder. However, when administered via intravenous infusion, its effects are short-lived due to rapid clearance. Here we describe the synthesis of deuterated analogues of DMT with the aim of prolonging the half-life and decreasing the clearance rate while maintaining similar pharmacological effects. The molecule with the greatest degree of deuteration at the α-carbon (N,N-D2-dimethyltryptamine, D2-DMT) demonstrated the longest half-life and intrinsic clearance in hepatocyte mitochondrial fractions when compared with DMT. The in vitro receptor binding profile of D2-DMT was comparable to that of DMT, with the highest affinity at the 5-HT1A, 5-HT2A, and 5-HT2C receptors. D2-DMT was therefore the preferred candidate to consider for further evaluation.

A Brief Review on the Potential of Psychedelics for Treating Alzheimer's Disease and Related Depression

Alzheimer's disease (AD), the most common form of senile dementia, is poised to place an even greater societal and healthcare burden as the population ages. With few treatment options for the symptomatic relief of the disease and its unknown etiopathology, more research into AD is urgently needed. Psychedelic drugs target AD-related psychological pathology and symptoms such as depression. Using microdosing, psychedelic drugs may prove to help combat this devastating disease by eliciting psychiatric benefits via acting through various mechanisms of action such as serotonin and dopamine pathways. Herein, we review the studied benefits of a few psychedelic compounds that may show promise in treating AD and attenuating its related depressive symptoms. We used the listed keywords to search through PubMed for relevant preclinical, clinical research, and review articles. The putative mechanism of action (MOA) for psychedelics is that they act mainly as serotonin receptor agonists and induce potential beneficial effects for treating AD and related depression.

N, N-Dimethyltryptamine (DMT)-Occasioned Familiarity and the Sense of Familiarity Questionnaire (SOF-Q)

This study investigated the sense of familiarity attributed to N, N-dimethyltryptamine (DMT) experiences. 227 naturalistic inhaled-DMT experiences reporting a sense of familiarity were included. No experiences referenced a previous DMT or psychedelic experience as the source of the familiarity. A high prevalence of concomitant features discordant from ordinary consciousness were identified: features of a mystical experience (97.4%), ego-dissolution (16.3%), and a "profound experience of death" (11.0%). The Sense of Familiarity Questionnaire (SOF-Q) was developed assessing 19 features of familiarity across 5 themes: (1) Familiarity with the Feeling, Emotion, or Knowledge Gained; (2) Familiarity with the Place, Space, State, or Environment; (3) Familiarity with the Act of Going Through the Experience; (4) Familiarity with Transcendent Features; and (5) Familiarity Imparted by an Entity Encounter. Bayesian latent class modeling yielded two stable classes of participants who shared similar SOF-Q responses. Class 1 participants responded, "yes" more often for items within "Familiarity Imparted by an Entity Encounter" and "Familiarity with the Feeling, Emotion, or Knowledge Gained." Results catalogued features of the sense of familiarity imparted by DMT, which appears to be non-referential to a previous psychedelic experience. Findings provide insights into the unique and enigmatic familiarity reported during DMT experiences and offer a foundation for further exploration into this intriguing phenomenon.

Infoveillance and Critical Analysis of the Systematically Reviewed Literature on Dimethyltryptamine and the "God Molecule"

Aboriginals of Latin America have used DMT (N,N-dimethyltryptamine) in ritualistic ceremonies for centuries. Nevertheless, there are limited data on web users' interest concerning DMT. We aim to review the literature and explore the spatial-temporal mapping of online search behavior concerning DMT, 5-MeO-DMT, and the Colorado River toad via Google Trends over the past 10 years (2012-2022) while using 5 search terms: "N,N-dimethyltryptamine", "5-methoxy-N,N-dimethyltryptamine", "5-MeO-DMT", "Colorado River toad", and "Sonoran Desert toad". Literature analysis conveyed novel information concerning DMT's past shamanic and present-day illicit uses, showcased experimental trials on DMT uses for neurotic disorders, and highlighted potential uses in modern medicine. DMT's geographic mapping signals originated mainly from Eastern Europe, the Middle East, and Far East Asia. In contrast, 5-MeO-DMT signals prevailed in Western Europe, Indo-China, and Australasia. Signals concerning the toad originated from the Americas, Australia, India, the Philippines, and Europe. Web users searched the most for "N,N-dimethyltryptamine" and "5-MeO-DMT". Three terms exhibited significant upgoing linear temporal trends: "5-MeO-DMT" (β = 0.37, p < 0.001), "Sonoran Desert toad" (β = 0.23, p < 0.001), and "Colorado River toad" (β = 0.17, p < 0.001). The literature and Infoedemiology data provided crucial information concerning DMT's legal status, risks and benefits, and potential for abuse. Nonetheless, we opine that in the upcoming decades, physicians might use DMT to manage neurotic disorders pending a change in its legal status.

Pharmacokinetics of N,N-dimethyltryptamine in Humans

BACKGROUND AND OBJECTIVE

N,N-dimethyltryptamine (DMT) is a psychedelic compound under development for the treatment of major depressive disorder (MDD). This study evaluated the preclinical and clinical pharmacokinetics and metabolism of DMT in healthy subjects.

METHODS

The physiochemical properties of DMT were determined using a series of in vitro experiments and its metabolic profile was assessed using monoamine oxidase (MAO) and cytochrome P450 (CYP) inhibitors in hepatocyte and mitochondrial fractions. Clinical pharmacokinetics results are from the phase I component of a phase I/IIa randomised, double-blind, placebo-controlled, parallel-group, dose-escalation trial (NCT04673383). Healthy adults received single escalating doses of DMT fumarate (SPL026) via a two-phase intravenous (IV) infusion. Dosing regimens were calculated based on pharmacokinetic modelling and predictions with progression to each subsequent dose level contingent upon safety and tolerability.

RESULTS

In vitro clearance of DMT was reduced through the inhibition of MAO-A, CYP2D6 and to a lesser extent CYP2C19. Determination of lipophilicity and plasma protein binding was low, indicating that a high proportion of DMT is available for distribution and metabolism, consistent with the very rapid clinical pharmacokinetics. Twenty-four healthy subjects received escalating doses of DMT administered as a 10-min infusion over the dose range of 9-21.5 mg (DMT freebase). DMT was rapidly cleared for all doses: mean elimination half-life was 9-12 min. All doses were safe and well tolerated and there was no relationship between peak DMT plasma concentrations and body mass index (BMI) or weight.

CONCLUSION

This is the first study to determine, in detail, the full pharmacokinetics profile of DMT following a slow IV infusion in humans, confirming rapid attainment of peak plasma concentrations followed by rapid clearance. These findings provide evidence which supports the development of novel DMT infusion regimens for the treatment of MDD.

CLINICAL TRIAL REGISTRATION

Registered on ClinicalTrials.gov (NCT04673383).

Interaction of psychedelic tryptamine derivatives with a lipid bilayer

Naturally occurring psychedelics have been used for a long time as remedies or in religious ceremonies and recreational activities. Recent studies have proven the therapeutic potential of some psychedelic compounds to safely treat a wide range of diseases such as anxiety, depression, migraine, and addiction. It is hypothesized that psychedelic compounds like tryptamines can exert their effects by two possible mechanisms: binding to the transmembrane serotonin receptor and/or modifying the properties of the neuronal membrane that can alter the conformational equilibrium and desensitize receptors. The impact of three different tryptamine class compounds with a tertiary amine (dimethyltryptamine, bufotenine, and 5-MeO-DMT) in both neutral and charged forms on a model bilayer lipid membrane are studied using all-atom MD simulations. All compounds partition into the bilayer, and change membrane properties, but to different extents. We determine the tendency of compounds to partition into the membrane by free energy calculations. Neutral tryptamines partition into the bilayer almost completely. Dimethyltryptamine and 5-MeO-DMT cross the membrane spontaneously during the simulation time, but bufotenine does not, although it has the maximum effect on the structural properties of the membrane. However, protonated compounds partition partially into the bilayer and cannot pass through the middle of the membrane during the simulation time. In this way, subtle alteration of chemical structure can play a significant role in the improvement or deterioration of partitioning of these compounds into the bilayer and their passage across the membrane.

Sex-specificity of the C. elegans metabolome

Recent studies of animal metabolism have revealed large numbers of novel metabolites that are involved in all aspects of organismal biology, but it is unclear to what extent metabolomes differ between sexes. Here, using untargeted comparative metabolomics for the analysis of wildtype animals and sex determination mutants, we show that C. elegans hermaphrodites and males exhibit pervasive metabolomic differences. Several hundred small molecules are produced exclusively or in much larger amounts in one sex, including a host of previously unreported metabolites that incorporate building blocks from nucleoside, carbohydrate, lipid, and amino acid metabolism. A subset of male-enriched metabolites is specifically associated with the presence of a male germline, whereas enrichment of other compounds requires a male soma. Further, we show that one of the male germline-dependent metabolites, an unusual dipeptide incorporating N,N-dimethyltryptophan, increases food consumption, reduces lifespan, and accelerates the last stage of larval development in hermaphrodites. Our results serve as a foundation for mechanistic studies of how the genetic sex of soma and germline shape the C. elegans metabolome and provide a blueprint for the discovery of sex-dependent metabolites in other animals.

Anadenanthera colubrina (Vell) Brenan: Ethnobotanical, phytochemical, pharmacological and toxicological aspects

ETHNOPHARMACOLOGICAL RELEVANCE

Anadenanthera colubrina (Vell.) Brenan is an endemic tree to South America and different parts of it are used by the population for the treatment of various diseases, as well as in indigenous rituals. This species has high pharmacological potential but may present toxic potential due to the presence of psychotropic compounds.

AIM OF THE STUDY

To review published studies with the species A. colubrina regarding ethnobotanical, phytochemical, pharmacological and toxicological aspects, as well as discuss perspectives for new research and protection of this species.

MATERIALS AND METHODS

A literature review was performed by accessing published articles on databases such as: PubMed, Science Direct, Scielo, Scopus, Taylor and Francis online, Springer Link, National Center for Biotechnology Information (NCBI), ACS Publications, Chemspider and Google Scholar. The keywords used were: "Anadenanthera colubrina" or "Mimosa colubrina" or "Piptadenia colubrina" or "Piptadenia macrocarpa" or "Piptadenia grata" or "Anadenanthera macrocarpa" and "medicinal plants" or "pharmacological" or "phytochemicals" or "traditional use" or "toxicological" or "ethnobotanical" or "pre-clinical trial" or "clinical". Articles found by database searches and search engines were screened at four stages: (i) title screening, (ii) locality screening, (iii) abstract screening, and (iv) full text. Other articles found through supplementary searches were screened in the full text whenever available. Each article was assessed by three reviewers at the title and abstract screening stages, except for those found in Portuguese databases that were assessed by the native reviewer.

RESULTS

This robust tree has been popularly useful for agroeconomic, medicinal and as a hallucinogen in religious rituals. According to the published studies, the main parts of the plant are the bark and seeds that are mostly used for respiratory conditions and as entheogens, respectively. It is a rich traditional herbal medicine with many pharmacological properties such as anti-inflammatory, antinociceptive, antidiarrheal, wound healing, antimicrobial, antitumoral, antioxidant, antiaddictive, insecticide and allelopathic that were described in in vitro and in vivo assays, and approximately 56 compounds were identified, suggesting a therapeutic potential for this species. Although most relate to medicinal uses, these are preliminaries and do not show the mechanism of action. The phytochemical assays showed the presence of phenolic compounds, flavonoids, triterpenes, steroids and alkaloids. Some of the compounds are anadanthoflavone, which is exclusive to this species, and no pharmacological or toxicological studies have yet demonstrated this compound. Another important compound is bufotenine which was isolated from seeds and is related to hallucinogenic and antiviral activity. The extracts made from leaves, bark, gum, and fruits appear to be safe, according to both in vivo and in vitro toxicology testing, which all shown low toxicity. Due to the presence of bufotenine in the seeds, it can be toxic, however, it was not found in toxicological assays with the seed extracts.

CONCLUSIONS

Therefore, part of the studies confirms the popular use of A. colubrina, however, more assays with isolated compounds and with the different extracts are necessary to corroborate other uses and the mechanism of action of their pharmacological effects needs to discuss in more detail. Therefore, the present review would be identified the gaps and suggests further studies oriented to validate the popular use. Thus, it must be noted that the use of this species must be controlled in order to minimize the environmental impact, as most of the pharmacological potential was shown with the bark and seeds. Due to its wide use in folk medicine, it is part of the Brazilian medicinal species with priority for conservation.

The Bright Side of Psychedelics: Latest Advances and Challenges in Neuropharmacology

The need to identify effective therapies for the treatment of psychiatric disorders is a particularly important issue in modern societies. In addition, difficulties in finding new drugs have led pharmacologists to review and re-evaluate some past molecules, including psychedelics. For several years there has been growing interest among psychotherapists in psilocybin or lysergic acid diethylamide for the treatment of obsessive-compulsive disorder, of depression, or of post-traumatic stress disorder, although results are not always clear and definitive. In fact, the mechanisms of action of psychedelics are not yet fully understood and some molecular aspects have yet to be well defined. Thus, this review aims to summarize the ethnobotanical uses of the best-known psychedelic plants and the pharmacological mechanisms of the main active ingredients they contain. Furthermore, an up-to-date overview of structural and computational studies performed to evaluate the affinity and binding modes to biologically relevant receptors of ibogaine, mescaline, N,N-dimethyltryptamine, psilocin, and lysergic acid diethylamide is presented. Finally, the most recent clinical studies evaluating the efficacy of psychedelic molecules in some psychiatric disorders are discussed and compared with drugs already used in therapy.

Indolethylamine N-methyltransferase (INMT) is not essential for endogenous tryptamine-dependent methylation activity in rats

Indolethylamine N-methyltransferase (INMT) is a transmethylation enzyme that utilizes the methyl donor S-adenosyl-L-methionine to transfer methyl groups to amino groups of small molecule acceptor compounds. INMT is best known for its role in the biosynthesis of N,N-Dimethyltryptamine (DMT), a psychedelic compound found in mammalian brain and other tissues. In mammals, biosynthesis of DMT is thought to occur via the double methylation of tryptamine, where INMT first catalyzes the biosynthesis of N-methyltryptamine (NMT) and then DMT. However, it is unknown whether INMT is necessary for the biosynthesis of endogenous DMT. To test this, we generated a novel INMT-knockout rat model and studied tryptamine methylation using radiometric enzyme assays, thin-layer chromatography, and ultra-high-performance liquid chromatography tandem mass spectrometry. We also studied tryptamine methylation in recombinant rat, rabbit, and human INMT. We report that brain and lung tissues from both wild type and INMT-knockout rats show equal levels of tryptamine-dependent activity, but that the enzymatic products are neither NMT nor DMT. In addition, rat INMT was not sufficient for NMT or DMT biosynthesis. These results suggest an alternative enzymatic pathway for DMT biosynthesis in rats. This work motivates the investigation of novel pathways for endogenous DMT biosynthesis in mammals.

Ayahuasca's therapeutic potential: What we know - and what not

The therapeutic potential of the psychedelic brew ayahuasca has been investigated in preclinical and clinical studies. Currently, the most consistent evidence refers to depression. However, various studies suggest that ayahuasca may comprise therapeutic benefits in other health conditions. This narrative review provides a comprehensive, up-to-date overview of ayahuasca's therapeutic effects in diverse clinical conditions in human (clinical, cross-sectional, observational, and qualitative) and preclinical (animal and in vitro) studies. In addition to summarizing and discussing the most commonly studied conditions, such as depression, anxiety, and substance use disorders (SUD), we also examine less frequently studied psychiatric, neurological, and physical conditions. Moreover, we discuss evidence from epidemiological studies on the impact of regular, long-term ayahuasca use on health and psychosocial outcomes. Overall, evidence for depression and SUD is more consistent, with numerous and diverse studies. However, a growing body of evidence suggests that other conditions equally relevant to public health might be promising targets for ayahuasca's therapeutic effects. This includes preliminary studies indicating potential for grief, eating disorders, posttraumatic stress disorder, personality disorders, Parkinson's and Alzheimer's disease, and severe physical illnesses (e.g., cancer, chronic conditions). Moreover, preliminary evidence in long-term ayahuasca users does not suggest detrimental effects but possible benefits for individual and collective health. In light of the emerging evidence of psychedelic drugs as therapeutic agents, it is essential to further investigate in rigorous designs the therapeutic potential of ayahuasca in conditions other than depression.

Key Characteristics and Development of Psychoceuticals: A Review

Psychoceuticals have brought benefits to the pharmacotherapeutic management of central nervous system (CNS) illnesses since the 19th century. However, these drugs have potential side effects or lack high response rates. This review covers twenty drugs' biochemical mechanisms, benefits, risks, and clinical trial reports. For this study, medications from seven psychoceutical organizations were reviewed and evaluated. Nineteen drugs were chosen from the organizations, and one was selected from the literature. The databases used for the search were Pubmed, Google Scholar, and NIH clinical trials. In addition, information from the organizations' websites and other sources, such as news reports, were also used. From the list of drugs, the most common targets were serotonergic, opioid, and N-methyl-D-aspartate (NMDA) receptors. These drugs have shown promise in psychiatric illnesses such as substance abuse, post-traumatic stress disorder (PTSD), anxiety, depression, and neurological conditions, such as Parkinson's disease, traumatic brain injury, and neuroinflammation. Some of these drugs, however, are still early in development, so their therapeutic significance cannot be determined. These twenty drugs have promising benefits, but their clinical usage and efficacy must still be explored.

Rumors of Psychedelics, Psychotropics and Related Derivatives in Vachellia and Senegalia in Contrast with Verified Records in Australian Acacia

There are almost 1000 species of Acacia sensu stricto in Australia, while the 44 species and 4 subspecies in southern Africa were taxonomically revised in the year 2011 to Senegalia and Vachellia. There are rumors of a chemical similarity between the Australian Acacia and their southern African sister genera. Chemical analysis has unequivocally demonstrated the presence of tryptamines (i.e., DMT), β-carbolines, histamines, and phenethylamines in Australian species. However, reliable published data were not found in support of similar alkaloids in southern African (or even African) species, indicating the need for exploratory phytochemical analysis. Interestingly, the Australian species are more like the Vachellia and Senegalia from the Americas. While many reliable chemical studies have been found, there are several more that report only tentative results. Tentative data and anecdotal accounts are included in the current review to guide researchers to areas where further work can be done. For example, the current review encourages further phytochemical work to confirm if the two metabolite families, tryptamine and β-carboline alkaloids, occur together in a single specimen. Tryptamines and β-carbolines are the prerequisite ingredients of the South American psychotropic drink ayahuasca, which utilizes two different species to create this synergistic combination. These observations and others are discussed in light of geochemical variability, the potential ethnobotanical implications, and the need for further research to confirm or nullify anecdotal reports and tentative chromatographic/spectroscopic data in southern African species.

Molecular Pathways of the Therapeutic Effects of Ayahuasca, a Botanical Psychedelic and Potential Rapid-Acting Antidepressant

Ayahuasca is a psychoactive brew traditionally used in indigenous and religious rituals and ceremonies in South America for its therapeutic, psychedelic, and entheogenic effects. It is usually prepared by lengthy boiling of the leaves of the bush Psychotria viridis and the mashed stalks of the vine Banisteriopsis caapi in water. The former contains the classical psychedelic N,N-dimethyltryptamine (DMT), which is thought to be the main psychoactive alkaloid present in the brew. The latter serves as a source for β-carbolines, known for their monoamine oxidase-inhibiting (MAOI) properties. Recent preliminary research has provided encouraging results investigating ayahuasca’s therapeutic potential, especially regarding its antidepressant effects. On a molecular level, pre-clinical and clinical evidence points to a complex pharmacological profile conveyed by the brew, including modulation of serotoninergic, glutamatergic, dopaminergic, and endocannabinoid systems. Its substances also interact with the vesicular monoamine transporter (VMAT), trace amine-associated receptor 1 (TAAR1), and sigma-1 receptors. Furthermore, ayahuasca’s components also seem to modulate levels of inflammatory and neurotrophic factors beneficially. On a biological level, this translates into neuroprotective and neuroplastic effects. Here we review the current knowledge regarding these molecular interactions and how they relate to the possible antidepressant effects ayahuasca seems to produce.

Preliminary evidence of links between ayahuasca use and the corpus callosum

Background

Recent research suggests that ayahuasca and its alkaloid-containing ingredients may be helpful in the treatment and prevention of certain movement and neurodegenerative disorders. However, such research is still in its infancy and more studies in normative samples seem necessary to explore effects of ayahuasca on clinically relevant brain structures, such as the corpus callosum.

Aims

The purpose of the present study was to investigate links between ayahuasca use and callosal structure in a normative sample.

Methods

Using structural imaging data from 22 ayahuasca users and 22 matched controls we compared the thickness of the corpus callosum between both groups at 100 equidistant points across the entire midsagittal surface. In addition, we investigated point-wise correlations between callosal thickness and the number of past ayahuasca sessions.

Results

The corpus callosum was significantly thicker within the isthmus in the ayahuasca group than in the control group. There was also a significant positive correlation between callosal thickness and the number of past ayahuasca sessions within the rostral body, albeit none of these effects survived corrections for multiple comparisons. No region was significantly thicker in the control than in the ayahuasca group, and no callosal region was negatively linked to ayahuasca use, even at uncorrected significance thresholds.

Conclusion

This study provides preliminary evidence of links between ayahuasca use and the corpus callosum. However, future studies need to replicate these findings, preferably using larger sample sizes and ideally also utilizing longitudinal research designs, to draw any practical conclusion and offer implications for follow-up clinical research.

The complete organellar genomes of the entheogenic plant Psychotria viridis (Rubiaceae), a main component of the ayahuasca brew

Psychotria viridis (Rubioideae: Rubiaceae), popularly known as chacrona, is commonly found as a shrub in the Amazon region and is well-known to produce psychoactive compounds, such as the N,N-dimethyltryptamine (DMT). Together with the liana Banisteropsis caapi, P. viridis is one of the main components of the Amerindian traditional, entheogenic beverage known as ayahuasca. In this work, we assembled and annotated the organellar genomes (ptDNA and mtDNA), presenting the first genomics resources for this species. The P. viridis ptDNA exhibits 154,106 bp, encoding all known ptDNA gene repertoire found in angiosperms. The Psychotria genus is a complex paraphyletic group, and according to phylogenomic analyses, P. viridis is nested in the Psychotrieae clade. Comparative ptDNA analyses indicate that most Rubiaceae plastomes present conserved ptDNA structures, often showing slight differences at the junction sites of the major four regions (LSC-IR-SSC). For the mitochondrion, assembly graph-based analysis supports a complex mtDNA organization, presenting at least two alternative and circular mitogenomes structures exhibiting two main repeats spanning 24 kb and 749 bp that may symmetrically isomerize the mitogenome into variable arrangements and isoforms. The circular mtDNA sequences (615,370 and 570,344 bp) encode almost all plant mitochondrial genes (except for the ccmC, rps7, rps10, rps14, rps19, rpl2 and rpl16 that appears as pseudogenes, and the absent genes sdh3, rps2, rsp4, rsp8, rps11, rpl6, and rpl10), showing slight variations related to exclusive regions, ptDNA integration, and relics of previous events of LTR-RT integration. The detection of two mitogenomes haplotypes is evidence of heteroplasmy as observed by the complex organization of the mitochondrial genome using graph-based analysis. Taken together, these results elicit the primary insights into the genome biology and evolutionary history of Psychotria viridis and may be used to aid strategies for conservation of this sacred, entheogenic species.

Significance of mammalian N, N-dimethyltryptamine (DMT): A 60-year-old debate

N,N-dimethyltryptamine (DMT) is a potent psychedelic naturally produced by many plants and animals, including humans. Whether or not DMT is significant to mammalian physiology, especially within the central nervous system, is a debate that started in the early 1960s and continues to this day. This review integrates historical and recent literature to clarify this issue, giving special attention to the most controversial subjects of DMT's biosynthesis, its storage in synaptic vesicles and the activation receptors like sigma-1. Less discussed topics, like DMT's metabolic regulation or the biased activation of serotonin receptors, are highlighted. We conclude that most of the arguments dismissing endogenous DMT's relevance are based on obsolete data or misleading assumptions. Data strongly suggest that DMT can be relevant as a neurotransmitter, neuromodulator, hormone and immunomodulator, as well as being important to pregnancy and development. Key experiments are addressed to definitely prove what specific roles DMT plays in mammalian physiology.

Three Naturally-Occurring Psychedelics and Their Significance in the Treatment of Mental Health Disorders

Classical psychedelics represent a family of psychoactive substances with structural similarities to serotonin and affinity for serotonin receptors. A growing number of studies have found that psychedelics can be effective in treating various psychiatric conditions, including post-traumatic stress disorder, major depressive disorder, anxiety, and substance use disorders. Mental health disorders are extremely prevalent in the general population constituting a major problem for the public health. There are a wide variety of interventions for mental health disorders, including pharmacological therapies and psychotherapies, however, treatment resistance still remains a particular challenge in this field, and relapse rates are also quite high. In recent years, psychedelics have become one of the promising new tools for the treatment of mental health disorders. In this review, we will discuss the three classic serotonergic naturally occurring psychedelics, psilocybin, ibogaine, and N, N-dimethyltryptamine, focusing on their pharmacological properties and clinical potential. The purpose of this article is to provide a focused review of the most relevant research into the therapeutic potential of these substances and their possible integration as alternative or adjuvant options to existing pharmacological and psychological therapies.

Phenomenology and content of the inhaled N, N-dimethyltryptamine (N, N-DMT) experience

Understanding the phenomenology and content of the inhaled N, N, dimethyltryptamine (N, N-DMT) experience is critical to facilitate and support ongoing research and therapeutic models targeting mental health conditions and central nervous system pathology. A qualitative analysis was conducted of all N, N-DMT experiences posted to the r/DMT Reddit community over a 10-year period from 2009 to 2018. A total of 3778 experiences from 3305 posts were included in this study. A median dose of N, N-DMT of 40.0 mg [interquartile range (IQR), 27.5 to 50.0] and a median experience duration of 10 min (IQR, 5.0 to 15.0) were identified. The most common somatic effects were somaesthesias (n = 1415, 37.5%) and an auditory ringing (n = 583, 15.4%). Visualizations predominantly consisted of fractals, shapes, patterns (n = 1231, 32.6%) and vivid colours (n = 953, 25.2%). Entity encounters were reported in 45.5% (n = 1719) of the experiences and involved predominantly a feminine phenotype (n = 416, 24.2%); deities (n = 293, 17.0%); aliens (n = 281, 16.3%); creature-based entities (n = 158, 9.2%, including reptilian and insectoid beings); mythological beings (n = 144, 8.4%, including machine elves); and jesters (n = 112, 6.5%). Entity interactions were predominantly positive (n = 600, 34.9% of encounters) involving benevolent, comforting, protecting, or outwardly caring interactions. A companion-type, pedagogical, or guide-type interaction was identified 32.4% of encounters (n = 557). Common typology, architecture, and structural features of the "DMT world" included descriptions of alternate or higher dimensions (n = 952, 25.2%); rooms [n = 582, 15.4%, including the "waiting room" (n = 105, 2.8%)], and a tunnel (n = 390, 10.3%). Features of mystical and ego-dissolution experiences were common. Additional rewarding aspects were identified, including a sense of familiarity and the acceptance/removal of the fear of death. Challenging and difficult responses were less frequent but also documented. Statements of profundity were identified in 232 experiences (6.1%), including pronouncing the experience or an aspect of the experience as the most "beautiful" or feeling the most "beautiful" of their life (n = 47, 1.2%). This study identified common phenomenological themes and content of naturalistic inhaled N, N-DMT experiences. Major thematic domains included (1) physical and somatic experiences; (2) visualizations and imagery; (3) entity encounters including entity phenotype, descriptors, attributes, disposition, and characteristics of the interaction; (4) typology, architectural features, structural characteristics, and scenery of the "DMT world"; (5) alerations in consciousness (including mystical experiences, out-of-body experiences, and ego-dissolution); (6) emotional responses (including positive, rewarding, difficult, and challenging); and (7) statements of profundity.

Ayahuasca blocks ethanol preference in an animal model of dependence and shows no acute toxicity

ETHNOPHARMACOLOGICAL RELEVANCE

Ayahuasca, a psychoactive beverage prepared from Banisteriopsis caapi and Psychotria viridis, is originally used by Amazon-based indigenous and mestizo groups for medicinal and ritualistic purposes. Nowadays, ayahuasca is used in religious and shamanic contexts worldwide, and preliminary evidence from preclinical and observational studies suggests therapeutic effects of ayahuasca for the treatment of substance (including alcohol) use disorders.

AIM OF THE STUDY

To investigate the initial pharmacological profile of ayahuasca and its effects on ethanol rewarding effect using the conditioned place preference (CPP) paradigm in mice.

MATERIALS AND METHODS

Ayahuasca beverage was prepared using extracts of B. caapi and P. viridis, and the concentration of active compounds was assessed through high performance liquid chromatography (HPLC). The following behavioral tests were performed after ayahuasca administration: general pharmacological screening (13, 130, or 1300 mg/kg - intraperitoneally - i.p., and 65, 130, 1300, or 2600 mg/kg - via oral - v.o.); acute toxicity test with elevated doses (2600 mg/kg - i.p., and 5000 mg/kg - v.o.); motor activity, motor coordination, and hexobarbital-induced sleeping time potentiation (250, 500, or 750 mg/kg ayahuasca or vehicle - v.o.). For the CPP test, the animals received ayahuasca (500 mg/kg - v.o.) prior to ethanol (1.8 g/kg - i.p.) or vehicle (control group - i.p.) during conditioning sessions.

RESULTS

Ayahuasca treatment presented no significant effect on motor activity, motor coordination, hexobarbital-induced sleeping latency or total sleeping time, and did not evoke signs of severe acute toxicity at elevated oral doses. Ayahuasca pre-treatment successfully inhibited the ethanol-induced CPP and induced CPP when administered alone.

CONCLUSIONS

Our results indicate that ayahuasca presents a low-risk acute toxicological profile when administered orally, and presents potential pharmacological properties that could contribute to the treatment of alcohol use disorders.

Impact of Two Neuronal Sigma-1 Receptor Modulators, PRE084 and DMT, on Neurogenesis and Neuroinflammation in an Aβ1-42-Injected, Wild-Type Mouse Model of AD

Alzheimer's disease (AD) is the most common form of dementia characterized by cognitive dysfunctions. Pharmacological interventions to slow the progression of AD are intensively studied. A potential direction targets neuronal sigma-1 receptors (S1Rs). S1R ligands are recognized as promising therapeutic agents that may alleviate symptom severity of AD, possibly via preventing amyloid-β-(Aβ-) induced neurotoxicity on the endoplasmic reticulum stress-associated pathways. Furthermore, S1Rs may also modulate adult neurogenesis, and the impairment of this process is reported to be associated with AD. We aimed to investigate the effects of two S1R agonists, dimethyltryptamine (DMT) and PRE084, in an Aβ-induced in vivo mouse model characterizing neurogenic and anti-neuroinflammatory symptoms of AD, and the modulatory effects of S1R agonists were analyzed by immunohistochemical methods and western blotting. DMT, binding moderately to S1R but with high affinity to 5-HT receptors, negatively influenced neurogenesis, possibly as a result of activating both receptors differently. In contrast, the highly selective S1R agonist PRE084 stimulated hippocampal cell proliferation and differentiation. Regarding neuroinflammation, DMT and PRE084 significantly reduced Aβ1-42-induced astrogliosis, but neither had remarkable effects on microglial activation. In summary, the highly selective S1R agonist PRE084 may be a promising therapeutic agent for AD. Further studies are required to clarify the multifaceted neurogenic and anti-neuroinflammatory roles of these agonists.

The promise of psychedelic research

The use of psychedelics as medicines and for overall better brain health is potentially one of the most transformative developments given their immediate and long-lasting therapeutic effects across a plethora of neuropsychiatric disorders and, more recently, some neurodegenerative diseases. The US psychedelic drugs market is forecasted to grow by 16.3% by 2027 due to the increasing prevalence of treatment-resistant depression and mental health disorders. Decades-long restrictions, which date back to when psychedelics were declared controlled substances in 1970, have been lifted to allow researchers to publish on the therapeutic benefits of psychedelics. This review will feature the incredible depth of research underway revealing how psychedelics impact brain structure and function to treat mental health and other neurological disorders.

Hallucinogenic drugs and their potential for treating fear-related disorders: Through the lens of fear extinction

Fear-related disorders, mainly phobias and post-traumatic stress disorder, are highly prevalent, debilitating disorders that pose a significant public health problem. They are characterized by aberrant processing of aversive experiences and dysregulated fear extinction, leading to excessive expression of fear and diminished quality of life. The gold standard for treating fear-related disorders is extinction-based exposure therapy (ET), shown to be ineffective for up to 35% of subjects. Moreover, ET combined with traditional pharmacological treatments for fear-related disorders, such as selective serotonin reuptake inhibitors, offers no further advantage to patients. This prompted the search for ways to improve ET outcomes, with current research focused on pharmacological agents that can augment ET by strengthening fear extinction learning. Hallucinogenic drugs promote reprocessing of fear-imbued memories and induce positive mood and openness, relieving anxiety and enabling the necessary emotional engagement during psychotherapeutic interventions. Mechanistically, hallucinogens induce dynamic structural and functional neuroplastic changes across the fear extinction circuitry and temper amygdala's hyperreactivity to threat-related stimuli, effectively mitigating one of the hallmarks of fear-related disorders. This paper provides the first comprehensive review of hallucinogens' potential to alleviate symptoms of fear-related disorders by focusing on their effects on fear extinction and the underlying molecular mechanisms. We overview both preclinical and clinical studies and emphasize the advantages of hallucinogenic drugs over current first-line treatments. We highlight 3,4-methylenedioxymethamphetamine and ketamine as the most effective therapeutics for fear-related disorders and discuss the potential molecular mechanisms responsible for their potency with implications for improving hallucinogen-assisted psychotherapy.

The clinical pharmacology and potential therapeutic applications of 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT)

5‐methoxy‐N,N‐dimethyltryptamine (5‐MeO‐DMT) is a naturally occurring tryptamine that primarily acts as an agonist at the 5‐HT1A and 5‐HT2A receptors, whereby affinity for the 5‐HT1A subtype is highest. Subjective effects following 5‐MeO‐DMT administration include distortions in auditory and time perception, amplification of emotional states, and feelings of ego dissolution that usually are short‐lasting, depending on the route of administration. Individual dose escalation of 5‐MeO‐DMT reliably induces a “peak” experience, a state thought to be a core predictor of the therapeutic efficacy of psychedelics. Observational studies and surveys have suggested that single exposure to 5‐MeO‐DMT can cause rapid and sustained reductions in symptoms of depression, anxiety, and stress. 5‐MeO‐DMT also stimulates neuroendocrine function, immunoregulation, and anti‐inflammatory processes, which may contribute to changes in mental health outcomes. To date, only one clinical trial has been published on 5‐MeO‐DMT, demonstrating the safety of vaporized dosing up to 18 mg. Importantly, the rapid onset and short duration of the 5‐MeO‐DMT experience may render it more suitable for individual dose‐finding strategies compared with longer‐acting psychedelics. A range of biotech companies has shown an interest in the development of 5‐MeO‐DMT formulations for a range of medical indications, most notably depression. Commercial development will therefore be the most important resource for bringing 5‐MeO‐DMT to the clinic. However, fundamental research will also be needed to increase understanding of the neurophysiological and neural mechanisms that contribute to the potential clinical effects of 5‐MeO‐DMT and its sustainability and dissemination over time. Such studies are less likely to be conducted as part of drug development programs and are more likely to rely on independent, academic initiatives.

Features of Cognitive and Emotional Sphere of a Teenager with Epiphysis Pathology and Concomitant Speech Disorder: An Analysis of a Single Case

<p style="text-align: justify;">The study of the features of cognitive impairments in various cerebral organic pathologies allows us to understand the role of individual structures of the brain in the implementation of mental activity and determine the appropriate ways of providing psychological assistance to patients. In a situation of rare pathology, the analysis of individual clinical cases is useful. The aim of this research was to study the state of cognitive functions in a 13-year-old male teenager with a cystic restructuring of the pineal gland and concomitant undifferentiated impairment of expressive speech. Changes in the epiphysis were detected in the patient in less than a month before this psychological study. During the examination, methods of pathopsychological and neuropsychological diagnostics, and projective graphic tests were used. In the course of neuropsychological research on a teenager, a violation of the ability to compose a syllabic kinetic scheme of utterance and, in general, a lack of dynamic and kinesthetic praxis, as well as interhemispheric interaction and auditory-speech memory were revealed. The main ways of providing psychological assistance to the patient were identified: neuropsychological correction aimed at restoring impaired speech function based on preserved higher mental functions, and restoration of the communicative function of speech. The obtained results of psychological research require further understanding and verification, primarily in order to understand the pathogenesis of cognitive disorders in the situation of cystic pineal gland rearrangement.</p>

Therapeutic effect of an ayahuasca analogue in clinically depressed patients: a longitudinal observational study

RATIONALE

Studies have suggested mental health improvements following the use of the psychotropic plant concoction ayahuasca in non-clinical and clinical samples.

OBJECTIVES

The present observational study assessed depressive symptomatology in 20 clinically depressed patients (symptom score > 13 on the Beck's Depression Inventory) before attendance of an ayahuasca ceremony and 1 month and 1 year after. Secondary measures included ratings of altered states of consciousness and ego dissolution during the ayahuasca ceremony as well as global measures of mindfulness, satisfaction with life, depression, anxiety, and stress.

RESULTS

Twenty participants completed baseline and 1-day follow-up, 19 completed measures at 1-month follow-up, and 17 completed measures at 1-year follow-up. BDI scores reduced from baseline (M = 22.7) to all post-ceremony measures (Ms 11.45, 12.89, and 8.88, for 1-day, 1-month, and 1-year follow-up, respectively). After 1 day, 12/20 participants were in remission (BDI < 13). Remission rates after 1 month and 1 year were 13/19 and 12/17, respectively. Three participants remained mildly depressed (BDI 14-19) at the 1-month and 1-year follow-up. Two participants did not respond and remained at a moderate/severe level of depression at 1-year follow-up. Reductions on the secondary mental health measures and increases in mindfulness and satisfaction with life were found up to 1 year post-ceremony. Improvements in clinical depression and mental health correlated with levels of experienced ego dissolution and oceanic boundlessness during the ceremony up to 1 month after the ceremony. Engagement in additional mental health treatments or use of another psychedelic during study participation may have contributed to improved mental health ratings at 1-year follow-up.

CONCLUSION

Ayahuasca produces long-term mental health improvements in clinically depressed patients, which highlights its therapeutic potential.

Administration of N,N-dimethyltryptamine (DMT) in psychedelic therapeutics and research and the study of endogenous DMT

As with all drugs, the route, form, and/or dose of a substance administered or applied can play a defining role in its overall pharmacology and use as a therapeutic. This review will focus on these factors as they relate to the psychedelic N,N-dimethyltryptamine (DMT). It will examine the positive and negative aspects of different formulations and routes of administration of DMT and the observed effects from such administrations in the form of ayahuasca teas; oral "pharmahuasca"; injections by intravenous (IV) and intramuscular (IM) routes; inhalation, insufflation; and other routes; and high-dose, low-dose, and "micro-dose" effects. The review will consider possible oral route of administration alternatives that would not require concomitant use of a monoamine oxidase inhibitor. The review will then address the current research findings for DMT from in vivo and in vitro studies as well as the possibility that these findings may be revealing the role of endogenous DMT in normal brain function.

3,4-Methylenedioxy methamphetamine, synthetic cathinones and psychedelics: From recreational to novel psychotherapeutic drugs

The utility of classical drugs used to treat psychiatric disorders (e.g., antidepressants, anxiolytics) is often limited by issues of lack of efficacy, delayed onset of action or side effects. Psychoactive substances have a long history of being used as tools to alter consciousness and as a gateway to approach the unknown and the divinities. These substances were initially obtained from plants and animals and more recently by chemical synthesis, and its consumption evolved toward a more recreational use, leading to drug abuse-related disorders, trafficking, and subsequent banning by the authorities. However, these substances, by modulation of certain neurochemical pathways, have been proven to have a beneficial effect on some psychiatric disorders. This evidence obtained under medically controlled conditions and often associated with psychotherapy, makes these substances an alternative to conventional medicines, to which in many cases the patient does not respond properly. Such disorders include post-traumatic stress disease and treatment-resistant depression, for which classical drugs such as MDMA, ketamine, psilocybin and LSD, among others, have already been clinically tested, reporting successful outcomes. The irruption of new psychoactive substances (NPS), especially during the last decade and despite their recreational and illicit uses, has enlarged the library of substances with potential utility on these disorders. In fact, many of them were synthetized with therapeutic purposes and were withdrawn for concrete reasons (e.g., adverse effects, improper pharmacological profile). In this review we focus on the basis, existing evidence and possible use of synthetic cathinones and psychedelics (specially tryptamines) for the treatment of mental illnesses and the properties that should be found in NPS to obtain new therapeutic compounds.

A Phase 1, Dose-Ranging Study to Assess Safety and Psychoactive Effects of a Vaporized 5-Methoxy-N, N-Dimethyltryptamine Formulation (GH001) in Healthy Volunteers

5-Methoxy-N,N-Dimethyltryptamine (5-MeO-DMT) is a tryptamine with ultra-rapid onset and short duration of psychedelic effects. Prospective studies for other tryptamines have suggested beneficial effects on mental health outcomes. In preparation for a study in patients with depression, the present study GH001-HV-101 aimed to assess the impact of four different dose levels of a novel vaporized 5-MeO-DMT formulation (GH001) administered via inhalation as single doses of 2 (N = 4), 6 (N = 6), 12 (N = 4) and 18 mg (N = 4), and in an individualized dose escalation regimen (N = 4) on the safety, tolerability, and the dose-related psychoactive effects in healthy volunteers (N = 22). The psychedelic experience was assessed with a novel Peak Experience Scale (PES), the Mystical Experience Questionnaire (MEQ), the Ego Dissolution Inventory (EDI), the Challenging Experience Questionnaire (CEQ), and the 5-Dimensional Altered States of Consciousness Questionnaire (5D-ASC). Further aims were to assess the impact of 5-MeO-DMT on cognitive functioning, mood, and well-being. Higher doses of 5-MeO-DMT produced significant increments in the intensity of the psychedelic experience ratings as compared to the lowest 2 mg dose on all questionnaires, except the CEQ. Prominent effects were observed following single doses of 6, 12, and 18 mg on PES and MEQ ratings, while maximal effects on PES, MEQ, EDI, and 5D-ASC ratings were observed following individualized dose escalation of 5-MeO-DMT. Measures of cognition, mood, and well-being were not affected by 5-MeO-DMT. Vital signs at 1 and 3 h after administration were not affected and adverse events were generally mild and resolved spontaneously. Individualized dose escalation of 5-MeO-DMT may be preferable over single dose administration for clinical applications that aim to maximize the experience to elicit a strong therapeutic response.

1H Nuclear Magnetic Resonance: A Future Approach to the Metabolic Profiling of Psychedelics in Human Biofluids?

While psychedelics may have therapeutic potential for treating mental health disorders such as depression, further research is needed to better understand their biological effects and mechanisms of action when considering the development of future novel therapy approaches. Psychedelic research could potentially benefit from the integration of metabonomics by proton nuclear magnetic resonance (1H NMR) spectroscopy which is an analytical chemistry-based approach that can measure the breakdown of drugs into their metabolites and their metabolic consequences from various biofluids. We have performed a systematic review with the primary aim of exploring published literature where 1H NMR analysed psychedelic substances including psilocin, lysergic acid diethylamide (LSD), LSD derivatives, N,N-dimethyltryptamine (DMT), 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT) and bufotenin. The second aim was to assess the benefits and limitations of 1H NMR spectroscopy-based metabolomics as a tool in psychedelic research and the final aim was to explore potential future directions. We found that the most current use of 1H NMR in psychedelic research has been for the structural elucidation and analytical characterisation of psychedelic molecules and that no papers used 1H NMR in the metabolic profiling of biofluids, thus exposing a current research gap and the underuse of 1H NMR. The efficacy of 1H NMR spectroscopy was also compared to mass spectrometry, where both metabonomics techniques have previously shown to be appropriate for biofluid analysis in other applications. Additionally, potential future directions for psychedelic research were identified as real-time NMR, in vivo 1H nuclear magnetic resonance spectroscopy (MRS) and 1H NMR studies of the gut microbiome. Further psychedelic studies need to be conducted that incorporate the use of 1H NMR spectroscopy in the analysis of metabolites both in the peripheral biofluids and in vivo to determine whether it will be an effective future approach for clinical and naturalistic research.

Sub-acute and long-term effects of ayahuasca on mental health and well-being in healthy ceremony attendants: A replication study

Background and aims

There is a growing body of evidence suggesting that the psychedelic plant tea, ayahuasca, holds therapeutic potential. Uthaug et al. (2018) demonstrated that a single dose of ayahuasca improved mental health sub-acutely and 4-weeks post-ceremony in healthy participants. The present study aimed to replicate and extend these findings. A first objective was to assess the sub-acute and long-term effects of ayahuasca on mental health and well-being in first-time and experienced users. A second aim was to extend the assessment of altered states of consciousness and how they relate to changes in mental health.

Method

Ayahuasca ceremony attendants (N = 73) were assessed before, the day after, and four weeks following the ceremony.

Results

We replicated the reduction in self-reported stress 4-weeks post ceremony, but, in contrast, found no reduction in depression. Also, increased satisfaction with life and awareness the day after the ceremony, and its return to baseline 4 weeks later, were replicated. New findings were: reduced ratings of anxiety and somatization, and increased levels of non-judging 4-weeks post-ceremony. We replicated the relation between altered states of consciousness (e.g., experienced ego dissolution during the ceremony) and mental health outcomes sub-acutely. The effects of ayahuasca did not differ between experienced and first-time users.

Conclusion

Partly in line with previous findings, ayahuasca produces long-term improvements in affect in non-clinical users. Furthermore, sub-acute mental health ratings are related to the intensity of the psychedelic experience. Although findings replicate and highlight the therapeutic potential of ayahuasca, this needs to be confirmed in placebo-controlled studies.

From psychiatry to neurology: Psychedelics as prospective therapeutics for neurodegenerative disorders

The studies of psychedelics, especially psychedelic tryptamines like psilocybin, are rapidly gaining interest in neuroscience research. Much of this interest stems from recent clinical studies demonstrating that they have a unique ability to improve the debilitating symptoms of major depressive disorder (MDD) long-term after only a single treatment. Indeed, the Food and Drug Administration (FDA) has recently designated two Phase III clinical trials studying the ability of psilocybin to treat forms of MDD with "Breakthrough Therapy" status. If successful, the use of psychedelics to treat psychiatric diseases like depression would be revolutionary. As more evidence appears in the scientific literature to support their use in psychiatry to treat MDD on and substance use disorders (SUD), recent studies with rodents revealed that their therapeutic effects might extend beyond treating MDD and SUD. For example, psychedelics may have efficacy in the treatment and prevention of brain injury and neurodegenerative diseases such as Alzheimer's Disease. Preclinical work has highlighted psychedelics' ability to induce neuroplasticity and synaptogenesis, and neural progenitor cell proliferation. Psychedelics may also act as immunomodulators by reducing levels of proinflammatory biomarkers, including IL-1β, IL-6, and tumor necrosis factor-α (TNF-α). Their exact molecular mechanisms, and induction of cellular interactions, especially between neural and glial cells, leading to therapeutic efficacy, remain to be determined. In this review, we discuss recent findings and information on how psychedelics may act therapeutically on cells within the central nervous system (CNS) during brain injuries and neurodegenerative diseases.

Lysergic Acid Diethylamide, Psilocybin and Dimethyltryptamine in Depression Treatment: A Systematic Review

Despite many different kinds of substances available for depression treatment, depression itself still appears to be a clinical challenge. Recently, formerly illicit substances came to scientists' attention, including lysergic acid diethylamide (LSD), psilocybin and dimethyltryptamine (DMT). Some studies suggest that these substances might be effective in depression treatment. The aim of this study was to evaluate the efficiency of LSD, psilocybin and DMT in depression treatment in the light of current medical literature. The authors followed the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines for this systematic review. The authors searched the PubMed and Cochrane Library databases to identify relevant publications. Finally, 10 papers were included. Most of the selected studies showed significant correlation between psilocybin and DMT use and reduction in depression symptom intensity. By analyzing qualified studies, it can be concluded that psilocybin and DMT could be useful in depression treatment, but further observations are still required.

Insights into S-adenosyl-l-methionine (SAM)-dependent methyltransferase related diseases and genetic polymorphisms

Enzymatic methylation catalyzed by methyltransferases has a significant impact on many human biochemical reactions. As the second most ubiquitous cofactor in humans, S-adenosyl-l-methionine (SAM or AdoMet) serves as a methyl donor for SAM-dependent methyltransferases (MTases), which transfer a methyl group to a nucleophilic acceptor such as O, As, N, S, or C as the byproduct. SAM-dependent methyltransferases can be grouped into different types based on the substrates. Here we systematically reviewed eight types of methyltransferases associated with human diseases. Catechol O-methyltransferase (COMT), As(III) S-adenosylmethionine methyltransferase (AS3MT), indolethylamine N-methyltransferase (INMT), phenylethanolamine N-methyltransferase (PNMT), histamine N-methyltransferase (HNMT), nicotinamide N-methyltransferase (NNMT), thiopurine S-methyltransferase (TPMT) and DNA methyltansferase (DNMT) are classic SAM-dependent MTases. Correlations between genotypes and disease susceptibility can be partially explained by genetic polymorphisms. The physiological function, substrate specificity, genetic variants and disease susceptibility associated with these eight SAM-dependent methyltransferases are discussed in this review.