Potential Therapeutic Effects of Psilocybin

The molecular structure, vibrational spectra, solvation effect, non-covalent interactions investigations of psilocin

Psilocin, or 4-HO-DMT (or 3-(2-dimethylaminoethyl)-1H-indol-4-ol), is a psychoactive alkaloid substance from the tryptamine family, isolated from Psilocybe mushrooms. This substance is being studied by various research groups because it has a clear therapeutic effect in certain dosages. In this work, the study of the structure and properties of psilocin was carried using theoretical methods: the effects of polar solvents (acetonitrile, dimethylsulfoxide, water, and tetrahydrofuran) on the structural parameters, spectroscopic properties (Raman, IR, and UV-Vis), frontier molecular orbital (FMO), molecular electrostatic potential (MEP) surface, and nonlinear optical parameters (NLO). Theoretical calculations were performed at the B3LYP/6-311++G(d,p) level by the density functional theory (DFT) method. IEFPCM was used to account for solvent effects. The types and nature of non-covalent interactions (NCI) between psilocin and solvent molecules were determined using Atoms in Molecules (AIM), the reduced density gradient method (RDG), the electron localization function (ELF), and the localization orbital locator (LOL). Experimental and calculated FT-IR, FT-Raman, and UV-Vis spectra were compared and found to be in good agreement.

The role of psilocybin in depressive disorders

Depression is a serious psychiatric disorder with a high incidence of morbidity and mortality and psilocybin with psychotherapy has emerged as a promising potential in the treatment of depressive disorders. A review of psilocybin use in patients with depressive disorders is presented.A search was conducted investigating the use of psilocybin in patients with depressive disorders and treatment resistant depression via PubMed/MEDLINE, EMBASE, and Google Scholar in October 2023; all publication types were permitted and limited for English-language. Keyword search terms included: "psilocybin" or "psychedelics" and "depression", or "major depressive disorder", or "treatment-resistant depression". Controlled and uncontrolled clinical trials utilizing psilocybin with psychological support for major depressive disorder and treatment-resistant depression, as well as in patients with depression and cancer related anxiety have demonstrated immediate and sustained antidepressant and anxiolytic effects. Psilocybin has a favorable safety profile and was well-tolerated in clinical trials. Psilocybin's abuse potential is low and clinical research suggests the potential of psilocybin to produce rapid and lasting antidepressant effects up to 12 months post-treatment. Psilocybin may offer a valuable contribution as an option to the currently available pharmacological and psychotherapeutic agents for patients with major depressive disorders, treatment-resistant depression as well as for patients with depression and comorbid terminal cancer. Future studies are needed to demonstrate these findings and any synergistic interaction between psilocybin and the psychological support offered to patients during sessions.

Single administration of a psychedelic [(R)-DOI] influences coping strategies to an escapable social stress

Psychedelic compounds have potentially rapid, long-lasting anxiolytic, antidepressive and anti-inflammatory effects. We investigated whether the psychedelic compound (R)-2,5-dimethoxy-4-iodoamphetamine [(R)-DOI], a selective 5-HT2A receptor partial agonist, decreases stress-related behavior in male mice exposed to repeated social aggression. Additionally, we explored the likelihood that these behavioral changes are related to anti-inflammatory properties of [(R)-DOI]. Animals were subjected to the Stress Alternatives Model (SAM), an escapable social stress paradigm in which animals develop reactive coping strategies - remaining in the SAM arena (Stay) with a social aggressor, or dynamically initiated stress coping strategies that involve utilizing the escape holes (Escape) to avoid aggression. Mice expressing these behavioral phenotypes display behaviors like those in other social aggression models that separate animals into stress-vulnerable (as for Stay) or stress-resilient (as for Escape) groups, which have been shown to have distinct inflammatory responses to social stress. These results show that Stay animals have heightened cytokine gene expression, and both Stay and Escape mice exhibit plasma and neural concentrations of the inflammatory cytokine tumor necrosis factor-α (TNFα) compared to unstressed control mice. Additionally, these results suggest that a single administration of (R)-DOI to Stay animals in low doses, can increase stress coping strategies such as increasing attention to the escape route, promoting escape behavior, and reducing freezing during socially aggressive interaction in the SAM. Lower single doses of (R)-DOI, in addition to shifting behavior to suggest anxiolytic effects, also concomitantly reduce plasma and limbic brain levels of the inflammatory cytokine TNFα.

Increased reactivity of the paraventricular nucleus of the hypothalamus and decreased threat responding in male rats following psilocin administration

Psychedelics have experienced renewed interest following positive clinical effects, however the neurobiological mechanisms underlying effects remain unclear. The paraventricular nucleus of the hypothalamus (PVN) plays an integral role in stress response, autonomic function, social behavior, and other affective processes. We investigated the effect of psilocin, the psychoactive metabolite of psilocybin, on PVN reactivity in Sprague Dawley rats. Psilocin increased stimulus-independent PVN activity as measured by c-Fos expression in male and female rats. Psilocin increased PVN reactivity to an aversive air-puff stimulus in males but not females. Reactivity was restored at 2- and 7-days post-injection with no group differences. Additionally, prior psilocin injection did not affect PVN reactivity following acute restraint stress. Experimental groups sub-classified by baseline threat responding indicate that increased male PVN reactivity is driven by active threat responders. These findings identify the PVN as a significant site of psychedelic drug action with implications for threat responding behavior.

Efficacy of psilocybin for treating symptoms of depression: systematic review and meta-analysis

OBJECTIVE

To determine the efficacy of psilocybin as an antidepressant compared with placebo or non-psychoactive drugs.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Five electronic databases of published literature (Cochrane Central Register of Controlled Trials, Medline, Embase, Science Citation Index and Conference Proceedings Citation Index, and PsycInfo) and four databases of unpublished and international literature (ClinicalTrials.gov, WHO International Clinical Trials Registry Platform, ProQuest Dissertations and Theses Global, and PsycEXTRA), and handsearching of reference lists, conference proceedings, and abstracts.

DATA SYNTHESIS AND STUDY QUALITY

Information on potential treatment effect moderators was extracted, including depression type (primary or secondary), previous use of psychedelics, psilocybin dosage, type of outcome measure (clinician rated or self-reported), and personal characteristics (eg, age, sex). Data were synthesised using a random effects meta-analysis model, and observed heterogeneity and the effect of covariates were investigated with subgroup analyses and metaregression. Hedges' g was used as a measure of treatment effect size, to account for small sample effects and substantial differences between the included studies' sample sizes. Study quality was appraised using Cochrane's Risk of Bias 2 tool, and the quality of the aggregated evidence was evaluated using GRADE guidelines.

ELIGIBILITY CRITERIA

Randomised trials in which psilocybin was administered as a standalone treatment for adults with clinically significant symptoms of depression and change in symptoms was measured using a validated clinician rated or self-report scale. Studies with directive psychotherapy were included if the psychotherapeutic component was present in both experimental and control conditions. Participants with depression regardless of comorbidities (eg, cancer) were eligible.

RESULTS

Meta-analysis on 436 participants (228 female participants), average age 36-60 years, from seven of the nine included studies showed a significant benefit of psilocybin (Hedges' g=1.64, 95% confidence interval (CI) 0.55 to 2.73, P<0.001) on change in depression scores compared with comparator treatment. Subgroup analyses and metaregressions indicated that having secondary depression (Hedges' g=3.25, 95% CI 0.97 to 5.53), being assessed with self-report depression scales such as the Beck depression inventory (3.25, 0.97 to 5.53), and older age and previous use of psychedelics (metaregression coefficient 0.16, 95% CI 0.08 to 0.24 and 4.2, 1.5 to 6.9, respectively) were correlated with greater improvements in symptoms. All studies had a low risk of bias, but the change from baseline metric was associated with high heterogeneity and a statistically significant risk of small study bias, resulting in a low certainty of evidence rating.

CONCLUSION

Treatment effects of psilocybin were significantly larger among patients with secondary depression, when self-report scales were used to measure symptoms of depression, and when participants had previously used psychedelics. Further research is thus required to delineate the influence of expectancy effects, moderating factors, and treatment delivery on the efficacy of psilocybin as an antidepressant.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42023388065.

Integrative Pharmacology in the Treatment of Substance Use Disorders

The detrimental physical, mental, and socioeconomic effects of substance use disorders (SUDs) have been apparent to the medical community for decades. However, it has become increasingly urgent in recent years to develop novel pharmacotherapies to treat SUDs. Currently, practitioners typically rely on monotherapy. Monotherapy has been shown to be superior to no treatment at all for most substance classes. However, many randomized controlled trials (RCTs) have revealed that monotherapy leads to poorer outcomes when compared with combination treatment in all specialties of medicine. The results of RCTs suggest that monotherapy frequently fails since multiple dysregulated pathways, enzymes, neurotransmitters, and receptors are involved in the pathophysiology of SUDs. As such, research is urgently needed to determine how various neurobiological mechanisms can be targeted by novel combination treatments to create increasingly specific yet exceedingly comprehensive approaches to SUD treatment. This article aims to review the neurobiology that integrates many pathophysiologic mechanisms and discuss integrative pharmacology developments that may ultimately improve clinical outcomes for patients with SUDs. Many neurobiological mechanisms are known to be involved in SUDs including dopaminergic, nicotinic, N-methyl-D-aspartate (NMDA), and kynurenic acid (KYNA) mechanisms. Emerging evidence indicates that KYNA, a tryptophan metabolite, modulates all these major pathophysiologic mechanisms. Therefore, achieving KYNA homeostasis by harmonizing integrative pathophysiology and pharmacology could prove to be a better therapeutic approach for SUDs. We propose KYNA-NMDA-α7nAChRcentric pathophysiology, the "conductor of the orchestra," as a novel approach to treat many SUDs concurrently. KYNA-NMDA-α7nAChR pathophysiology may be the "command center" of neuropsychiatry. To date, extant RCTs have shown equivocal findings across comparison conditions, possibly because investigators targeted single pathophysiologic mechanisms, hit wrong targets in underlying pathophysiologic mechanisms, and tested inadequate monotherapy treatment. We provide examples of potential combination treatments that simultaneously target multiple pathophysiologic mechanisms in addition to KYNA. Kynurenine pathway metabolism demonstrates the greatest potential as a target for neuropsychiatric diseases. The investigational medications with the most evidence include memantine, galantamine, and N-acetylcysteine. Future RCTs are warranted with novel combination treatments for SUDs. Multicenter RCTs with integrative pharmacology offer a promising, potentially fruitful avenue to develop novel therapeutics for the treatment of SUDs.

Deep CANALs: a deep learning approach to refining the canalization theory of psychopathology

Psychedelic therapy has seen a resurgence of interest in the last decade, with promising clinical outcomes for the treatment of a variety of psychopathologies. In response to this success, several theoretical models have been proposed to account for the positive therapeutic effects of psychedelics. One of the more prominent models is "RElaxed Beliefs Under pSychedelics," which proposes that psychedelics act therapeutically by relaxing the strength of maladaptive high-level beliefs encoded in the brain. The more recent "CANAL" model of psychopathology builds on the explanatory framework of RElaxed Beliefs Under pSychedelics by proposing that canalization (the development of overly rigid belief landscapes) may be a primary factor in psychopathology. Here, we make use of learning theory in deep neural networks to develop a series of refinements to the original CANAL model. Our primary theoretical contribution is to disambiguate two separate optimization landscapes underlying belief representation in the brain and describe the unique pathologies which can arise from the canalization of each. Along each dimension, we identify pathologies of either too much or too little canalization, implying that the construct of canalization does not have a simple linear correlation with the presentation of psychopathology. In this expanded paradigm, we demonstrate the ability to make novel predictions regarding what aspects of psychopathology may be amenable to psychedelic therapy, as well as what forms of psychedelic therapy may ultimately be most beneficial for a given individual.

Ethical considerations for psychedelic-assisted therapy in military clinical settings

Psychedelic treatments, particularly 3,4-methylenedioxymethamphetamine (MDMA)-assisted and psilocybin-assisted therapies, have recently seen renewed interest in their clinical potential to treat various mental health conditions. Clinical trials for both MDMA-assisted and psilocybin-assisted therapies have shown to be highly efficacious for post-traumatic stress disorder and major depression. Recent research trials for psychedelic-assisted therapies (PAT) have demonstrated that although they are resource-intensive, their effects are rapid-acting, durable and cost-effective. These results have generated enthusiasm among researchers seeking to investigate psychedelic therapies in active-duty service members of the US military, particularly those with treatment refractory mental health conditions. At the same time, psychedelics remain in early stages of clinical investigation, have not yet achieved regulatory approval for general clinical use and may confer unique psychological and neurobiological effects that could raise novel ethical considerations when treating active-duty service members. Should psychedelics achieve regulatory approval, military relevant considerations may include issues of access to these treatments, appropriate procedures for informed consent, confidentiality standards, and possible unanticipated mental health risks and other psychological sequelae. A service member's deployability, as well as their ability to return to full military duty following PAT, may also be of unique concern. The authors argue that MDMA-assisted therapy currently represents a promising treatment that should be more rapidly investigated as a clinical therapy for service members while still taking a measured approach that accounts for the many military-specific uncertainties that remain.

Giving Consent to the Ineffable

A psychedelic renaissance is currently taking place in mental healthcare. The number of psychedelic-assisted therapy trials is growing steadily, and some countries already grant psychiatrists special permission to use psychedelics in non-research contexts under certain conditions. These clinical advances must be accompanied by ethical inquiry. One pressing ethical question involves whether patients can even give informed consent to psychedelic-assisted therapy: the treatment's transformative nature seems to block its assessment, suggesting that patients are unable to understand what undergoing psychedelic-assisted therapy actually means for them and whether it aligns with their values. The present paper argues that patients often have sufficient knowledge to give informed consent because they know that they want to change their negative status quo and that psychedelic-assisted therapy offers an effective way to do so. Accordingly, patients can understand what the transformative nature of psychedelic-assisted therapy means for them and a make a value-aligned choice even if they are unable to anticipate the manifestation of a psychedelic experience.

Perioperative considerations for patients exposed to hallucinogens

Hallucinogen exposure in patients in the perioperative period presents challenges for anesthesiologists and other anesthesia providers. Acute and chronic exposure to these substances can cause physiological impacts that can affect the function of anesthetic and analgesic medications used during perioperative care. The objective of this narrative review is to educate readers on the wide array of hallucinogens and psychedelics that may influence the perioperative management of patients exposed to these substances. A narrative review of the literature surrounding hallucinogens and psychedelics was completed. Hallucinogens and psychedelics are quite varied in their mechanisms of action and therefore present a variety of perioperative implications and perioperative considerations. Many of these substances increase serotonin levels or act directly at serotonergic receptors. However, there are other relevant actions that may include varied mechanisms from N-methyl-D-aspartate receptor antagonism to stimulation of muscarinic receptors. With hallucinogen exposure rates on the rise, understanding the effects of hallucinogens is important for optimizing management and reducing risks perioperatively for patients with acute or chronic exposure.

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.

Phylogenomics of the psychoactive mushroom genus Psilocybe and evolution of the psilocybin biosynthetic gene cluster

Psychoactive mushrooms in the genus Psilocybe have immense cultural value and have been used for centuries in Mesoamerica. Despite the recent surge of interest in these mushrooms due to the psychotherapeutic potential of their natural alkaloid psilocybin, their phylogeny and taxonomy remain substantially incomplete. Moreover, the recent elucidation of the psilocybin biosynthetic gene cluster is known for only five of ~165 species of Psilocybe, four of which belong to only one of two major clades. We set out to improve the phylogeny of Psilocybe using shotgun sequencing of fungarium specimens, from which we obtained 71 metagenomes including from 23 types, and conducting phylogenomic analysis of 2,983 single-copy gene families to generate a fully supported phylogeny. Molecular clock analysis suggests the stem lineage of Psilocybe arose ~67 mya and diversified ~56 mya. We also show that psilocybin biosynthesis first arose in Psilocybe, with 4 to 5 possible horizontal transfers to other mushrooms between 40 and 9 mya. Moreover, predicted orthologs of the psilocybin biosynthetic genes revealed two distinct gene orders within the biosynthetic gene cluster that corresponds to a deep split within the genus, possibly a signature of two independent acquisitions of the cluster within Psilocybe.

Feasibility and effectiveness study of applying a hallucinogen harm reduction and integration model to a mindfulness thinking intervention using virtual reality: A randomized controlled trial

Objective

The purpose of this study was to investigate whether a virtual reality (VR) program designed and developed based on the hallucinogenic harm reduction and integration (PHRI) clinical model could be more effective in guiding positive thinking training, improving positive thinking awareness and ability, and, to some extent, facilitating personal efficacy and emotional state compared to a traditional VR program that places users in a virtual natural ecological environment to guide positive thinking training. We also sought to understand the factors that may influence the effectiveness of VR interventions and user experience.

Method

Seventy-six randomly recruited participants were divided into a control group and an experimental group of 38 participants, each according to a random number table, and were trained in VR meditation for eight weeks. The experimental group used a PHRI-based mindfulness program, while the control group used a traditional mindfulness meditation program. We used The Mindful Attention Awareness Scale and the PAD emotional three-dimensional scale to assess the level of state mindfulness and changes in the emotional state before and at the end of the experiment. The Immersive Tendencies Questionnaire measured the user's sense of presence and immersion in the virtual environment. The Five Facet Mindfulness Questionnaires and the Depression Anxiety and Stress Scale (DASS-21) were used at the baseline assessment stage before and at the 4-week follow-up after the experiment to assess the change in trait mindfulness levels due to the mindfulness training. The Five Facet Mindfulness Questionnaires and the DASS-21 were used to assess changes in mindfulness and mental health trait levels.

Results

At the end of the experiment, the MMSQ score was significantly lower in the control group than in the experimental group, while the ITQ score was significantly higher than in the experimental group, and both scores were statistically significant (p < 0.05). In the follow-up assessment four weeks after the end of the experiment, the FFMQ-15 score and the DASS-21 were significantly and statistically higher in the experimental group than in the control group (p < 0.05). Since the scores of the PAD scale did not obey a normal distribution, we used the Wilcoxon signed-rank test to assess the results, which proved that the experimental group had higher levels of emotional activation and arousal.

Conclusion

The VR positive thinking program developed based on PHRI can significantly increase the positive thinking state and emotional arousal and activation of the general population participants but does not directly lead to the growth of positive emotions. Moreover, this detached psychedelic scene brings users a weaker sense of presence and presence than traditional natural space scenes. Furthermore, it does not bring any intense simulator motion sickness symptoms. These findings suggest that VR programs developed based on PHRI have a more positive facilitation effect on the positive state and that this increase lasts longer than conventional VR-positive programs.

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.

Unveiling the Psychedelic Journey: An Appraisal of Psilocybin as a Profound Antidepressant Therapy

Depression, a global health concern with significant implications for suicide rates, remains challenging to treat effectively with conventional pharmacological options. The existing pharmaceutical interventions for these illnesses need daily dosing, are accompanied by various adverse effects, and may exhibit limited efficacy in certain cases. However, hope emerges from an unlikely source-Psilocybin, a natural hallucinogen found in certain mushrooms. Recently, this enigmatic compound has garnered attention for its potential therapeutic benefits in addressing various mental health issues, including depression. Psilocybin alters mood, cognition, and perception by acting on a particular subtype of serotonin receptors in the brain. It's feasible that these shifts in consciousness will promote healing development, offering a novel approach to depression management. This comprehensive review explores psilocybin, derived from specific mushrooms, and its implications in the treatment of depression. The study examines new perspectives and therapeutic possibilities surrounding psilocybin, addressing existing gaps in academic literature. It delves into its biosynthesis, unique mechanisms of action, therapeutic applications, and anti-depressive effects. By uncovering the potential of this mind-altering substance, the review aims to advance psychiatric care, offering hope to those globally affected by depression.

The central role of the Thalamus in psychosis, lessons from neurodegenerative diseases and psychedelics

The PD-DLB psychosis complex found in Parkinson's disease (PD) and Dementia with Lewy Bodies (DLB) includes hallucinations, Somatic Symptom/Functional Disorders, and delusions. These disorders exhibit similar presentation patterns and progression. Mechanisms at the root of these symptoms also share similarities with processes promoting altered states of consciousness found in Rapid Eye Movement sleep, psychiatric disorders, or the intake of psychedelic compounds. We propose that these mechanisms find a crucial driver and trigger in the dysregulated activity of high-order thalamic nuclei set in motion by ThalamoCortical Dysrhythmia (TCD). TCD generates the loss of finely tuned cortico-cortical modulations promoted by the thalamus and unleashes the aberrant activity of the Default Mode Network (DMN). TCD moves in parallel with altered thalamic filtering of external and internal information. The process produces an input overload to the cortex, thereby exacerbating DMN decoupling from task-positive networks. These phenomena alter the brain metastability, creating dreamlike, dissociative, or altered states of consciousness. In support of this hypothesis, mind-altering psychedelic drugs also modulate thalamic-cortical pathways. Understanding the pathophysiological background of these conditions provides a conceptual bridge between neurology and psychiatry, thereby helping to generate a promising and converging area of investigation and therapeutic efforts.

With great power comes great vulnerability: an ethical analysis of psychedelics' therapeutic mechanisms proposed by the REBUS hypothesis

Psychedelics are experiencing a renaissance in mental healthcare. In recent years, more and more early phase trials on psychedelic-assisted therapy have been conducted, with promising results overall. However, ethical analyses of this rediscovered form of treatment remain rare. The present paper contributes to the ethical inquiry of psychedelic-assisted therapy by analysing the ethical implications of its therapeutic mechanisms proposed by the relaxed beliefs under psychedelics (REBUS) hypothesis. In short, the REBUS hypothesis states that psychedelics make rigid beliefs revisable by increasing the influence of bottom-up input. Put differently, patients become highly suggestible and sensitive to context during a psychedelic session, amplifying therapeutic influence and effects. Due to that, patients are more vulnerable in psychedelic-assisted therapy than in other therapeutic interventions; they lose control during a psychedelic session and become dependent on the therapeutic setting (including the therapist). This enhanced vulnerability is ethically relevant and has been exploited by some therapists in the past. Therefore, patients in current research settings and starting mainstream medical settings need to be well informed about psychedelics' mechanisms and their implications to give valid informed consent to treatment. Furthermore, other security measures are warranted to protect patients from the vulnerability coming with psychedelic-assisted therapy.

The Psychedelic N,N-Dipropyltryptamine Prevents Seizures in a Mouse Model of Fragile X Syndrome via a Mechanism that Appears Independent of Serotonin and Sigma1 Receptors

The serotonergic psychedelic psilocybin shows efficacy in treating neuropsychiatric disorders, though the mechanism(s) underlying its therapeutic effects remain unclear. We show that a similar psychedelic tryptamine, N,N-dipropyltryptamine (DPT), completely prevents audiogenic seizures (AGS) in an Fmr1 knockout mouse model of fragile X syndrome at a 10 mg/kg dose but not at lower doses (3 or 5.6 mg/kg). Despite showing in vitro that DPT is a serotonin 5-HT2A, 5-HT1B, and 5-HT1A receptor agonist (with that rank order of functional potency, determined with TRUPATH Gα/βγ biosensors), pretreatment with selective inhibitors of 5-HT2A/2C, 5-HT1B, or 5-HT1A receptors did not block DPT's antiepileptic effects; a pan-serotonin receptor antagonist was also ineffective. Because 5-HT1A receptor activation blocks AGS in Fmr1 knockout mice, we performed a dose-response experiment to evaluate DPT's engagement of 5-HT1A receptors in vivo. DPT elicited 5-HT1A-dependent effects only at doses greater than 10 mg/kg, further supporting that DPT's antiepileptic effects were not 5-HT1A-mediated. We also observed that the selective sigma1 receptor antagonist, NE-100, did not impact DPT's antiepileptic effects, suggesting DPT engagement of sigma1 receptors was not a crucial mechanism. Separately, we observed that DPT and NE-100 at high doses caused convulsions on their own that were qualitatively distinct from AGS. In conclusion, DPT dose-dependently blocked AGS in Fmr1 knockout mice, but neither serotonin nor sigma1 receptor antagonists prevented this action. Thus, DPT might have neurotherapeutic effects independent of its serotonergic psychedelic properties. However, DPT also caused seizures at high doses, showing that DPT has complex dose-dependent in vivo polypharmacology.

Molecular Docking, MM-GBSA, and Molecular Dynamics Approach: 5-MeO-DMT Analogues as Potential Antidepressants

Since depression is a common mental illness affecting an estimated 5% of people worldwide, investigators are encouraged to develop effective antidepressants. According to the monoamine-deficiency hypothesis, the underlying pathophysiology of depression is a deficiency of some neurotransmitters (serotonin, norepinephrine, or dopamine) in the central nervous system. The neurotransmitter serotonin has drawn the most attention concerning depression. As per research, 5-methoxy-N, N-dimethyltryptamine (5-MeO-DMT) elevates inter-synaptic serotonin levels when administered as a single inhalation of vapor from dried toad secretion and leads to higher life satisfaction, convergent thinking, higher ratings of mindfulness, lower ratings of depression, and anxiety. Furthermore, although 5-MeO-DMT lowers stress biomarkers such as cortisol, it is a psychedelic with hallucinogenic effects. In the present study, analogues of 5-MeO-DMT are designed with the hope that they might have better therapeutic activity and lower psychedelic side effects. The current study aimed to look at 5-MeO-DMT analogues as possible antidepressants. We used 70,000 5-MeO-DMT analogues that were sketched using Marvin to conduct a High Throughput Virtual Screening method in hopes of finding potential 5-MeO-DMT analogues against the 5-Hydroxytryptamine 1A receptor (5-HT1AR; 7E2Y.pdb) as an agonist. The prediction of the analogue-protein interaction and the evaluation of the binding affinity is accomplished by employing molecular docking. The Glide XP docking data indicated that a total of 21 compounds had Glide gscores ranging from -11.41 to -6.53 kcal/mol. When compared to the standard 5-MeO-DMT with the binding affinity of -7.75 kcal/mol, 14 compounds showed better binding affinity. Furthermore, Molecular Mechanics -Generalised Born and Surface Area solvation (MM-GBSA) indicated a binding free energy range of -63.55 to -35.37 kcal/mol, and 18 compounds showed better binding free energy than standard 5-MeO-DMT (-41.42 kcal/mol). Through ligand binding interactions with Asp116, Phe361, Phe362, Ser190, Ser199, Val117, Trp358, Ala365, Pro369, Ile189, Tyr195, Ala203, Ile167, Tyr390, Cys120, Trp358, Val364, Ala365, and Leu368, these complexes were stabilized, according to the molecular dynamic simulation of 20453/7E2Y in 100ns.

Dendritogenic Potential of the Ethanol Extract from Lippia alba Leaves in Rat Cortical Neurons

A reduced dendritic complexity, especially in regions such as the hippocampus and the prefrontal cortex, has been linked to the pathophysiology of some neuropsychiatric disorders, in which synaptic plasticity and functions such as emotional and cognitive processing are compromised. For this reason, the identification of new therapeutic strategies would be enriched by the search for metabolites that promote structural plasticity. The present study evaluated the dendritogenic potential of the ethanol extract of Lippia alba, an aromatic plant rich in flavonoids and terpenes, which has been widely used in traditional medicine for its presumed analgesic, anxiolytic, and antidepressant potential. An in vitro model of rat cortical neurons was used to determine the kinetics of the plant's effect at different time intervals. Changes in morphological parameters of the neurons were determined, as well as the dendritic complexity, by Sholl analysis. The extract promotes the outgrowth of dendritic branching in a rapid and sustained fashion, without being cytotoxic to the cells. We found that this effect could be mediated by the phosphatidylinositol 3-kinase pathway, which is involved in mechanisms of neuronal plasticity, differentiation, and survival. The evidence presented in this study provides a basis for further research that, through in vivo models, can delve into the plant's therapeutic potential.

Does acute stress play a role in the lasting therapeutic effects of psychedelic drugs?

Psychedelic drugs, when used in the context of psychotherapy, can produce significant and long-lasting memories with enduring beneficial effects. Yet, the behavioral and neurobiological mechanisms that underlie these beneficial effects remain a mystery. Here, we suggest that both the quality and durability of memories of the drug-facilitated therapeutic experience may be mediated, in part, by the acute stress responses induced by the drugs. It is known that high doses of psychedelic drugs activate autonomic and hormonal stress responses. For evolutionarily adaptive reasons, acute stress is known to i) instill meaning to the immediate context in which it is experienced, and ii) lead to the formation of salient and lasting memories of the events surrounding the stress. Thus, the stress-inducing effect of psychedelic drugs may contribute to the reported sense of meaning, as well as the durability of the memory of the drug experience. When used in a therapeutic context these actions may i) enhance the salience of insights gained during the experience and ii) strengthen the memories formed by these experiences. Future empirical studies will help to determine whether acute stress contributes to the emotional significance and lasting effects of psychedelic-assisted psychotherapy.

Psilocybin history, action and reaction: A narrative clinical review

Hallucinogenic mushrooms have been used in religious and cultural ceremonies for centuries. Of late, psilocybin, the psychoactive compound in hallucinogenic mushrooms, has received increased public interest as a novel drug for treating mood and substance use disorders (SUDs). In addition, in recent years, some states in the United States have legalized psilocybin for medical and recreational use. Given this, clinicians need to understand the potential benefits and risks related to using psilocybin for therapeutic purposes so that they can accurately advise patients. This expert narrative review summarizes the scientific basis and clinical evidence on the safety and efficacy of psilocybin-assisted therapy for treating psychiatric disorders and SUDs. The results of this review are structured as a more extensive discussion about psilocybin's history, putative mechanisms of action, and recent legislative changes to its legal status. There is modest evidence of psilocybin-assisted therapy for treating depression and anxiety disorders. In addition, early data suggest that psilocybin-assisted therapy may effectively reduce harmful drinking in patients with alcohol use disorders. The evidence further suggests psilocybin, when administered under supervision (psilocybin-assisted therapy), the side effects experienced are mild and transient. The occurrence of severe adverse events following psilocybin administration is uncommon. Still, a recent clinical trial found that individuals in the psilocybin arm had increased suicidal ideations and non-suicidal self-injurious behaviors. Given this, further investigation into the safety and efficacy of psilocybin-assisted therapy is warranted to determine which patient subgroups are most likely to benefit and which are most likely to experience adverse outcomes related to its use.

Predictors of Pharmacy Students' Attitudes About the Therapeutic Use of Psilocybin

Background Psilocybin has been studied for its potential therapeutic benefits, particularly for the treatment of psychiatric disorders such as anxiety, depression, and obsessive-compulsive disorder. While more research is needed as psilocybin-assisted therapy becomes more prevalent, future pharmacists will probably be involved at some level. At present, pharmacists receive minimal training on psilocybin, and little is known about their attitudes toward its use for medical purposes. Findings from recent clinical studies have attempted to establish the safety and medical efficacy of psilocybin, leading to an increased interest in therapeutic psilocybin use in the United States. This study aimed to assess if self-assessed knowledge of psilocybin, concerns about adverse effects, and opinions about legalization will make statistically significant contributions to pharmacy students' attitudes about psilocybin use in practice. Methods Pharmacy students' self-assessed knowledge, concern for potential adverse effects, and perceptions of psilocybin were investigated using a cross-sectional survey study design. Data were collected from March 13 to April 7, 2023, from a convenience sample of 161 pharmacy students enrolled in an accredited pharmacy school in the southern region of the United States using a 41-item anonymous quantitative survey developed by the researchers that contained validated scales. The survey was delivered electronically. Multiple regression modeling was conducted to determine if self-assessed knowledge, concerns for adverse effects, and opinions about legalization would predict pharmacy students' attitudes about therapy-assisted psilocybin use. This study was approved by the Institutional Review Board of the authors' university. Results The mean age of the 161 participants was 24 years (SD = 2.981; range 20-40 years). Twenty (12.4%) participants reported previous use of psilocybin for recreational purposes and two (1.2%) reported having used it therapeutically. Many (n =121; 75.2%) of the participants believed that psilocybin should be decriminalized for therapeutic use, but only 54 (33.5%) thought it should be decriminalized for recreational use. A multiple linear regression model predicting "attitudes about psilocybin" (dependent variable) produced significant results: (F(4, 122) = 40.575, p < 0.001), with an R2 = 0.571 (adjusted R2 = 0.557). Greater "self-assessed knowledge about psilocybin," less "concern about possible negative effects," greater "belief in the decriminalization of psilocybin for recreational use," and greater "belief in the decriminalization of psilocybin for therapeutic use" (all independent variables) were associated with more positive perceptions about medical psilocybin. The percentage of variance in the scores accounted for by the model was 57%. Conclusions Pharmacy students may lack information and training regarding psilocybin and report a desire to learn more about it. Their attitudes about medical psilocybin may be driven by this desire to learn in addition to concerns about adverse effects and legalization issues. Due to the dearth of published information regarding the knowledge and acceptance of psilocybin as a viable treatment option for patients, further research in psychedelic-assisted treatments may be warranted.

Race and ethnicity moderate the associations between lifetime psilocybin use and crime arrests

Introduction

Psilocybin use has been linked to lowered odds of crime-related outcomes across a host of observational studies. No studies have investigated how these associations may differ among those of different races and ethnicities.

Methods

Using a nationally-representative sample of 734,061 adults from the National Survey on Drug Use and Health (2002-2020), we investigated whether race and ethnicity moderate the associations between lifetime psilocybin use and four measures of crime arrests (property crime, assault, serious violence, and miscellaneous crimes).

Results

First, we replicated prior findings and demonstrated that psilocybin confers lowered odds of crime arrests for all four outcomes in question. Second, we demonstrated that race and ethnicity moderate the associations between lifetime psilocybin use and crime arrests for three of our four outcomes. Third, we examined the associations between psilocybin and crime arrests across different races and ethnicities (White, Black, Indigenous, Asian, Multiracial, and Hispanic participants). Psilocybin conferred lowered odds of at least one crime arrest outcome for all racial and ethnic groups except for Black and Hispanic participants.

Discussion

Future investigations should take an intersectional approach to studying the interrelationship of sociodemographic factors, psychedelic use, and crime, examine the structural factors (i.e., systemic racism) that may underlie these results, and investigate whether psychedelics can alleviate mental health disorders that contribute to cycles of recriminalization for communities of color.

5-MeO-DMT modifies innate behaviors and promotes structural neural plasticity in mice

Serotonergic psychedelics are gaining increasing interest as potential therapeutics for a range of mental illnesses. Compounds with short-lived subjective effects may be clinically useful because dosing time would be reduced, which may improve patient access. One short-acting psychedelic is 5-MeO-DMT, which has been associated with improvement in depression and anxiety symptoms in early phase clinical studies. However, relatively little is known about the behavioral and neural mechanisms of 5-MeO-DMT, particularly the durability of its long-term effects. Here we characterized the effects of 5-MeO-DMT on innate behaviors and dendritic architecture in mice. We showed that 5-MeO-DMT induces a dose-dependent increase in head-twitch response that is shorter in duration than that induced by psilocybin at all doses tested. 5-MeO-DMT also substantially suppresses social ultrasonic vocalizations produced during mating behavior. 5-MeO-DMT produces long-lasting increases in dendritic spine density in the mouse medial frontal cortex that are driven by an elevated rate of spine formation. However, unlike psilocybin, 5-MeO-DMT did not affect the size of dendritic spines. These data provide insights into the behavioral and neural consequences underlying the action of 5-MeO-DMT and highlight similarities and differences with those of psilocybin.

Microbiome: The Next Frontier in Psychedelic Renaissance

The psychedelic renaissance has reignited interest in the therapeutic potential of psychedelics for mental health and well-being. An emerging area of interest is the potential modulation of psychedelic effects by the gut microbiome-the ecosystem of microorganisms in our digestive tract. This review explores the intersection of the gut microbiome and psychedelic therapy, underlining potential implications for personalized medicine and mental health. We delve into the current understanding of the gut-brain axis, its influence on mood, cognition, and behavior, and how the microbiome may affect the metabolism and bioavailability of psychedelic substances. We also discuss the role of microbiome variations in shaping individual responses to psychedelics, along with potential risks and benefits. Moreover, we consider the prospect of microbiome-targeted interventions as a fresh approach to boost or modulate psychedelic therapy's effectiveness. By integrating insights from the fields of psychopharmacology, microbiology, and neuroscience, our objective is to advance knowledge about the intricate relationship between the microbiome and psychedelic substances, thereby paving the way for novel strategies to optimize mental health outcomes amid the ongoing psychedelic renaissance.

The molecular basis of the antidepressant action of the magic mushroom extract, psilocin

Magic mushrooms, and their extract psilocybin, are well-known for their psychedelic properties and recreational use. Psilocin, the bio-active form of psilocybin, can potentially treat various psychiatric diseases. Psilocin putatively exerts its psychedelic effect as an agonist to the serotonin 2A receptor (5-HT2AR), which is also the receptor for the neurological hormone serotonin. The two key chemical differences between the two molecules are first, that the primary amine in serotonin is replaced with a tertiary amine in psilocin, and second, the hydroxyl group is substituted differently on the aromatic ring. Here, we find that psilocin can bind to 5-HT2AR with an affinity higher than serotonin, and provide the molecular logic behind the higher binding affinity of psilocin using extensive molecular dynamics simulations and free energy calculations. The binding free energy of psilocin is dependent upon the protonation states of the ligands, as well as that of the key residue in the binding site: Aspartate 155. We find that the tertiary amine of psilocin, and not the altered substitution of the hydroxyl group in the ring is responsible for the increased affinity of psilocin. We propose design rules for effective antidepressants based on molecular insights from our simulations.

Psychedelics, Meaningfulness, and the "Proper Scope" of Medicine: Continuing the Conversation

Psychedelics such as psilocybin reliably produce significantly altered states of consciousness with a variety of subjectively experienced effects. These include certain changes to perception, cognition, and affect,¹ which we refer to here as the acute subjective effects of psychedelics. In recent years, psychedelics such as psilocybin have also shown considerable promise as therapeutic agents when combined with talk therapy, for example, in the treatment of major depression or substance use disorder.² However, it is currently unclear whether the aforementioned acute subjective effects are necessary to bring about the observed therapeutic effects of psilocybin and other psychedelics. This uncertainty has sparked a lively-though still largely hypothetical-debate on whether psychedelics without subjective effects ("nonsubjective psychedelics" or "non-hallucinogenic psychedelics") could still have the same therapeutic impact, or whether the acute subjective effects are in fact necessary for this impact to be fully realized.^3,4,5.

Psychedelics reopen the social reward learning critical period

Psychedelics are a broad class of drugs defined by their ability to induce an altered state of consciousness1,2. These drugs have been used for millennia in both spiritual and medicinal contexts, and a number of recent clinical successes have spurred a renewed interest in developing psychedelic therapies3-9. Nevertheless, a unifying mechanism that can account for these shared phenomenological and therapeutic properties remains unknown. Here we demonstrate in mice that the ability to reopen the social reward learning critical period is a shared property across psychedelic drugs. Notably, the time course of critical period reopening is proportional to the duration of acute subjective effects reported in humans. Furthermore, the ability to reinstate social reward learning in adulthood is paralleled by metaplastic restoration of oxytocin-mediated long-term depression in the nucleus accumbens. Finally, identification of differentially expressed genes in the 'open state' versus the 'closed state' provides evidence that reorganization of the extracellular matrix is a common downstream mechanism underlying psychedelic drug-mediated critical period reopening. Together these results have important implications for the implementation of psychedelics in clinical practice, as well as the design of novel compounds for the treatment of neuropsychiatric disease.

Systems-level analysis of local field potentials reveals differential effects of lysergic acid diethylamide and ketamine on neuronal activity and functional connectivity

Psychedelic substances have in recent years attracted considerable interest as potential treatments for several psychiatric conditions, including depression, anxiety, and addiction. Imaging studies in humans point to a number of possible mechanisms underlying the acute effects of psychedelics, including changes in neuronal firing rates and excitability as well as alterations in functional connectivity between various brain nodes. In addition, animal studies using invasive recordings, have suggested synchronous high-frequency oscillations involving several brain regions as another key feature of the psychedelic brain state. To better understand how the imaging data might be related to high-resolution electrophysiological measurements, we have here analyzed the aperiodic part of the local field potential (LFP) in rodents treated with a classic psychedelic (LSD) or a dissociative anesthetic (ketamine). In addition, functional connectivity, as quantified by mutual information measures in the LFP time series, has been assessed with in and between different structures. Our data suggest that the altered brain states of LSD and ketamine are caused by different underlying mechanisms, where LFP power shifts indicate increased neuronal activity but reduced connectivity following ketamine, while LSD also leads to reduced connectivity but without an accompanying change in LFP broadband power.

Sex-specific effects of psychedelic drug exposure on central amygdala reactivity and behavioral responding

Psilocybin and its active metabolite psilocin have been shown to elicit rapid and long-lasting symptom improvements in a variety of affective psychiatric illnesses. However, the region-specific alterations underlying these therapeutic effects remain relatively unknown. The central amygdala (CeA) is a primary output region within the extended amygdala that is dysregulated in affective psychiatric disorders. Here, we measured CeA activity using the activity marker c-Fos and CeA reactivity using fiber photometry paired with an aversive air-puff stimulus. We found that psilocin administration acutely increased CeA activity in both males and females and increased stimulus specific CeA reactivity in females, but not males. In contrast, psilocin produced time-dependent decreases in reactivity in males, but not in females, as early as 2 days and lasting to 28 days post administration. We also measured behavioral responses to the air-puff stimulus and found sex-dependent changes in threat responding but not exploratory behavior or general locomotion. Repeated presentations of the auditory component of the air-puff were also performed and sex-specific effects of psilocin on CeA reactivity to the auditory-alone stimulus were also observed. This study provides new evidence that a single dose of psilocin produces sex-specific, time-dependent, and enduring changes in CeA reactivity and behavioral responding to specific components of an aversive stimulus.

Psychotherapy with Psilocybin for Depression: Systematic Review

Depression is a common mental health issue that affects 280 million people in the world with a high mortality rate, as well as being a leading cause of disability. Psychopharmacological therapies with psychedelics, particularly those with psilocybin, are showing promising potential for the treatment of depression, among other conditions. Some of their benefits include a rapid and exponential improvement in depressive symptoms and an increased sense of well-being that can last for months after the treatment, as well as a greater development of introspective capacity. The aim of this project was to provide experimental evidence about therapeutic procedures along with psilocybin for the treatment of major depressive disorder. The project highlights eight studies that examined this condition. Some of them dealt with treatment-resistant depression while others dealt with depression due to a life-threatening disease such as cancer. These publications affirm the efficiency of the psilocybin therapy for depression, with only one or two doses in conjunction with psychological support during the process.

[Attitudes of Mental Health Experts Towards Psilocybin]

OBJECTIVE

In recent years, studies investigating the use of psilocybin to treat mental disorders have shown promising results. In this context, this online survey investigated attitudes of trained psychiatrists and psychotherapists towards psilocybin and psilocybin-assisted therapies.

MATERIALS AND METHODS

A total of 530 valid responses from individuals with suitable job profiles were collected in this online survey. Statistical analysis was used to identify relevant predictors of attitude measures.

RESULTS

The opinions of experts in the treatment of mental disorders with psilocybin and psilocybin-assisted therapies varied widely, and the level of knowledge of the participants to some extent was low. A large number of participants considered treatment of mental disorders with psilocybin to be promising and treatment of depression with psilocybin was seen as promising by the majority of the participants. The results of this study suggest that a higher level of knowledge about psilocybin is associated with more optimistic views about its use in a therapeutic setting. Having additional scientific information led in some cases to more optimistic attitudes towards psilocybin and the use of psilocybin in the treatment of mental disorders.

CONCLUSION

If the scientific and public discourse on psilocybin continues to grow in the future, changes in the attitudes of psychotherapists and psychiatrists can be expected.

Race and ethnicity moderate the associations between lifetime psychedelic use (MDMA/ecstasy and psilocybin) and major depressive episodes

BACKGROUND

Psychedelics are receiving renewed attention within Western medicine as they represent potential treatments for many difficult-to-treat mental health disorders. However, psychedelic science is limited in its focus and inclusion of racial and ethnic minorities. Hence, this study examines whether race and ethnicity moderate the associations that naturalistic 3,4-methylenedioxymethamphetamine (MDMA)/ecstasy use and psilocybin use share with major depressive episodes (MDEs).

METHOD

Data for this project are from The National Survey on Drug Use and Health (2005-2019). Participants were adults aged 18 years and older (unweighted N = 596,187). This study used multivariable logistic regression to test the interaction between race and ethnicity and MDMA/ecstasy use and psilocybin use for predicting lifetime, past year, and past year severe MDEs.

RESULTS

Race and ethnicity significantly moderated the associations between MDMA/ecstasy use and psilocybin use and MDEs. For White participants, MDMA/ecstasy use and psilocybin use each were associated with lowered odds of all three MDE outcomes (adjusted odds ratio (aOR) range: 0.82-0.92). For Hispanic participants, MDMA/ecstasy use and psilocybin use each conferred lowered odds of only a past year MDE (MDMA/ecstasy aOR: 0.82; psilocybin aOR: 0.79). For Non-Hispanic Racial Minority participants, MDMA/ecstasy and psilocybin use did not confer lowered odds of any MDE outcomes.

CONCLUSION

Race and ethnicity have an impact on the associations that psychedelics share with mental health outcomes. Future research should explore the impact of identity and discrimination on the effects of psychedelics and should explore whether these substances can serve as effective treatments for minorities when used in culturally informed contexts.

Contextual Parameters Associated with Positive and Negative Mental Health in Recreational Psychedelic Users

Growing research exploring the utility of psychedelic substances suggests that they not only hold promise for clinical practice but may enhance mental health through recreational use as well. However, given the importance of set and setting for maximizing benefits and minimizing harms of drug use, it is important to develop a foundational understanding of the contextual factors associated with positive and negative mental health in psychedelic users. Accordingly, data were collected using an internet-based survey of psychedelic drug users (n = 511). Hierarchical regression analyses were used to explore to what degree life-time use, frequency of use, dose size, group use, intentions for use, and post-use integration predict mental health in psychedelic users. In particular, using psychedelics with high frequency and to cope with negative affect were found to predict negative mental health. Conversely, using psychedelics in a group setting, with self-expansive intentions, and integrating post-use were found to predict positive mental health. Findings suggest that recreational psychedelic use may either enhance or diminish mental health depending on the contextual parameters of use. Limitations and areas for further research are discussed.

A Review of Synthetic Access to Therapeutic Compounds Extracted from Psilocybe

Psychedelics are used for various pathologies of the central nervous system and are currently the subject of much research, some of which relates to the compounds contained in various Psilocybe-type hallucinogenic mushrooms. It is difficult, however, to obtain and purify sufficient quantities of these compounds from fungi to carry out biological studies, hence the need to develop simple and efficient synthetic routes. We review here the various syntheses used to obtain these molecules, focusing first on the classic historical syntheses, then the use of more recent metallo-catalyzed couplings and finally the known biocatalytic methods for obtaining these molecules. Other access routes are certainly possible and should be the subject of future research given the therapeutic interest of these compounds.

"A sense of the bigger picture:" A qualitative analysis of follow-up interviews with people with bipolar disorder who self-reported psilocybin use

OBJECTIVES

People with bipolar disorder (BD) spend more time depressed than manic/hypomanic, and depression is associated with greater impairments in psychosocial functioning and quality of life than mania/hypomania. Emerging evidence suggests psilocybin, the psychoactive compound in "magic mushrooms," is a promising treatment for unipolar depression. Clinical trials of psilocybin therapy have excluded people with BD as a precaution against possible adverse effects (e.g., mania). Our study centered the experiences of adults living with BD who consumed psilocybin-containing mushrooms, and aimed to (1) understand its subjective impacts on BD symptoms, (2) deepen understanding of Phase I survey results, and (3) elucidate specific contextual factors associated with adverse reactions in naturalistic settings.

METHODS

Following an international survey (Phase I), follow-up interviews were conducted with 15 respondents (Phase II) to further understand psilocybin use among adults with BD. As part of a larger mixed-methods explanatory sequential design study, reflexive thematic analysis was used to elaborate findings.

RESULTS

Three major themes containing sub-themes were developed. (1) Mental Health Improvements: (1.1) decreased impact and severity of depression, (1.2) increased emotion processing, (1.3) development of new perspectives, and (1.4) greater relaxation and sleep. (2) Undesired Mental Health Impacts: (2.1) changes in sleep, (2.2) increased mania severity, (2.3) hospitalization, and (2.4) distressing sensory experiences. (3) Salient Contextual Factors for psilocybin use included: (3.1) poly-substance use and psilocybin dose, (3.2) solo versus social experiences, and (3.3) pre-psilocybin sleep deprivation.

CONCLUSION

Our findings demonstrate both benefits and risks of psilocybin use in this population. Carefully designed clinical trials focused on safety and preliminary efficacy are warranted.

Self-transcendent experiences as promoters of ecological wellbeing? Exploration of the evidence and hypotheses to be tested

In recent years, much has been written on the role of different mental states and their potential to influence our way of thinking and, perhaps more importantly, the way we act. With the recent acceleration of environmental and mental health issues, alongside the limited effectiveness of existing interventions, an exploration of new approaches to deliver transformative change is required. We therefore explore the emerging potential of a type of mental state known as self-transcendent experiences (STEs) as a driver of ecological wellbeing. We focus on four types of STEs: those facilitated by experiences of flow, awe, and mindfulness, as well as by psychedelic-induced experiences. Some of these experiences can occur naturally, through sometimes unexpected encounters with nature or during immersion in every-day activities that one intrinsically enjoys, as well as through more intentional practices such as meditation or the administration of psychedelics in controlled, legal settings. We explore the evidence base linking each of the four types of STE to ecological wellbeing before proposing potential hypotheses to be tested to understand why STEs can have such beneficial effects. We end by looking at the factors that might need to be considered if STEs are going to be practically implemented as a means of achieving ecological wellbeing.

Initiating Pharmacologic Treatment in Tobacco-Dependent Adults

There is a strong evidence base for the use of existing pharmacotherapies to support tobacco cessation, alone or in combination, ideally with concurrent behavioral interventions. Future pharmacotherapies under development may assist in the most refractory cases. Incorporating current and future therapies into a longitudinal chronic care model for tobacco dependence will help a diverse range of patients achieve independence from nicotine addiction.

Potential Therapeutic Effects of Psilocybin: A Systematic Review

Psilocybin is a plant alkaloid that is derived from precursors of tryptamine and is present in many different types of mushrooms. It has been utilized by indigenous peoples of Central and South America for centuries in a ceremonial setting to promote spiritual experiences. Indigenous societies have long employed psilocybin and other 5-HT 2A agonist classic psychedelics in their rites. They were a focus in psychiatry in the middle of the 20th century as both experimental medicines and tools for studying brain function. Due to the fact that traditional psychedelics were being used for purposes other than medical research and in connection with the burgeoning counterculture by the late 1960s and early 1970s, these scientific investigations fell out of favor. However, thanks to a number of encouraging studies that validated the earlier research, interest in traditional psychedelics has surged among scientists in the 21st century. In this review, we examine therapeutic studies on psilocybin, the traditional psychedelic that has received the lion's share of recent attention. According to three controlled studies, psilocybin may reduce symptoms of depression and anxiety in the context of cancer-related psychological discomfort for at least six months after a single acute treatment for mood and anxiety disorders. Three months after two acute doses, individuals in a small, open-label study with treatment-resistant depression reported fewer depressive and anxiety symptoms. Small, open-label pilot studies on addiction have demonstrated encouraging success rates for alcohol and cigarette addiction. The review also briefly discusses the synthesis, mechanism of action, effects, molecular pharmacology, adverse effects, and contraindications of psilocybin.

Animal Behavior in Psychedelic Research

Psychedelic-assisted psychotherapy holds great promise in the treatment of mental health disorders. Research into 5-hydroxytryptamine 2A receptor (5-HT_2AR) agonist psychedelic compounds has increased dramatically over the past two decades. In humans, these compounds produce drastic effects on consciousness, and their therapeutic potential relates to changes in the processing of emotional, social, and self-referential information. The use of animal behavior to study psychedelics is under debate, and this review provides a critical perspective on the translational value of animal behavior studies in psychedelic research. Acute activation of 5-HT_2ARs produces head twitches and unique discriminative cues, disrupts sensorimotor gating, and stimulates motor activity while inhibiting exploration in rodents. The acute treatment with psychedelics shows discrepant results in conventional rodent tests of depression-like behaviors but generally induces anxiolytic-like effects and inhibits repetitive behavior in rodents. Psychedelics impair waiting impulsivity but show discrepant effects in other tests of cognitive function. Tests of social interaction also show conflicting results. Effects on measures of time perception depend on the experimental schedule. Lasting or delayed effects of psychedelics in rodent tests related to different behavioral domains appear to be rather sensitive to changes in experimental protocols. Studying the effects of psychedelics on animal behaviors of relevance to effects on psychiatric symptoms in humans, assessing lasting effects, publishing negative findings, and relating behaviors in rodents and humans to other more translatable readouts, such as neuroplastic changes, will improve the translational value of animal behavioral studies in psychedelic research. SIGNIFICANCE STATEMENT: Psychedelics like LSD and psilocybin have received immense interest as potential new treatments of psychiatric disorders. Psychedelics change high-order consciousness in humans, and there is debate about the use of animal behavior studies to investigate these compounds. This review provides an overview of the behavioral effects of 5-HT_2AR agonist psychedelics in laboratory animals and discusses the translatability of the effects in animals to effects in humans. Possible ways to improve the utility of animal behavior in psychedelic research are discussed.

Esketamine and Psilocybin—The Comparison of Two Mind-Altering Agents in Depression Treatment: Systematic Review

This publication discusses two compounds belonging to the psychoactive substances group which are studied in the context of depression treatment—psilocybin and esketamine. The former is a naturally occurring psychedelic. The latter was invented in the laboratory exactly 60 years ago. Although the substances were controversial in the past, recent studies indicate the potential of those substances as novel antidepressant agents. The PubMed/MEDLINE database was used to identify articles for systematic review, using the following search terms: (depression) AND (psilocybin) OR (ketamine). From 617 items, only 12 articles were obtained in the final analyses. Three articles were devoted to psilocybin in depression treatment and nine to esketamine. In most studies, esketamine showed a significant reduction in both depressive symptoms and suicidal ideation shortly after intake and after a month of treatment compared to baseline and to standard-of-care antidepressant agents. Psilocybin’s antidepressive effects occurred one day after intake and after 6–7 weeks of treatment and were maintained for up to 6 or 8 months of follow-up. One study indicated that psilocybin’s effects are comparable with and may be superior to escitalopram treatment. Both esketamine and psilocybin demonstrated rapid and long-term effects in reducing depression symptoms and, after overcoming some limitations, may be considered as novel antidepressant agents in future.

Attitudes and Beliefs about the Therapeutic Use of Psychedelic Drugs among Psychologists in the United States

Psychologists are a vital component of mental health treatment and their perceptions of psychedelic-assisted therapy are critical for future implementation. This cross-sectional quasi-experimental electronic survey study explored the attitudes about psychedelics used in treatment among 366 clinical psychologists in the United States. Participants expressed cautiously favorable attitudes toward therapeutic psychedelic experiences but indicated concern about possible psychiatric and neurocognitive risks. Most participants indicated that they lack an understanding of the full range of effects of psychedelics, would need to seek out additional consultation, and endorsed positive beliefs in the potential of psychedelic treatment and the need for further research. Overall, this research identified the need to increase education and training about psychedelics for psychologists in order to help increase knowledge and reduce stigma about psychedelic therapies.

Magic mushroom extracts in lipid membranes

The active hallucinogen of magic mushrooms, psilocin, is being repurposed to treat nicotine addiction and treatment-resistant depression. Psilocin belongs to the tryptamine class of psychedelic compounds which include the hormone serotonin. It is believed that psilocin exerts its effect by binding to the serotonin 5-HT_2A receptor. However, recent in-vivo evidence suggests that psilocin may employ a different mechanism to exert its effects. Membrane-mediated receptor desensitization of neurotransmitter receptors is one such mechanism. We compare the impact of the neutral and charged versions of psilocin and serotonin on the properties of zwitterionic and anionic lipid membranes using molecular dynamics simulations and calorimetry. Both compounds partition to the lipid interface and induce membrane thinning. The tertiary amine in psilocin, as opposed to the primary amine in serotonin, limits psilocin's impact on the membrane although more psilocin partitions into the membrane than serotonin. Calorimetry corroborates that both compounds induce a classical melting point depression like anesthetics do. Our results also lend support to a membrane-mediated receptor-binding mechanism for both psilocin and serotonin and provide physical insights into subtle chemical changes that can alter the membrane-binding of psychedelic compounds.

Examining Attitudes to Psilocybin: Should Candidates for Medical Psilocybin be Required to Pass a Contextual Suitability Test?

Due to increasing evidence of efficacy in treating mental health disorders, psilocybin may become a legal medicinal drug. This study tested the validity of Carhart-Harris and Nutt’s (2017) model of extra-pharmacological (EP) factors. It examined whether such factors should be considered in any psychological suitability test for medicinally prescribed psilocybin. Two hundred nineteen participants (101 self-identified females, 109 males, seven nonbinary people, and two who preferred not to say), in an age range of 18 to 68 years, completed three online measures of personality— Set, Setting, and Intention—and the Attitudes Toward Psilocybin (ATP) scale. The sample was equally divided between those who had used psychedelics (52.1%) and those who had no previous psychedelic use (47.5%). A series of stepwise linear regressions were run to examine whether EP factors predicted ATP scores. The ATP scale was tested for reliability, construct validity, and determinant validity and was deemed an appropriate measure. A model consisting of a positive Set, Openness to Experience, and lower Extraversion significantly predicted ATP scores. These findings supported the EP model and suggested that a suitability test may be a useful tool when determining whether a prescription of psilocybin is an appropriate course of treatment.