Therapeutic use of psilocybin: Practical considerations for dosing and administration

Psilocybin in pharmacotherapy of obsessive-compulsive disorder

Obsessive-compulsive disorder (OCD) is a chronic mental disease that affects approximately 2% of the population. Obsessions and compulsions are troublesome for patients and may disturb their everyday activities. The pathogenesis of this disease is still not fully elucidated, but dysfunctions of serotonin-, dopamine- and glutamate-mediated neurotransmission together with early maladaptive schemas seem of importance. Pharmacological treatment includes drugs affecting the serotoninergic, dopaminergic, and glutamatergic systems, such as selective serotonin reuptake inhibitors (SSRIs). Providing that up to 40% of patients with OCD are resistant to the currently available medications, there is a need for novel and effective therapies. Recent discoveries suggest that psilocybin, a non-physically addictive psychoactive substance, may ameliorate disease symptoms. When used in appropriate doses and under strict clinical control, psilocybin appears as a valuable treatment for OCD. This narrative article provides a thorough overview of OCD's etiology, current treatment options, and the emerging evidence supporting psilocybin's efficacy in managing OCD symptoms.

The Tolerability and Safety of Psilocybin in Psychiatric and Substance-Dependence Conditions: A Systematic Review

OBJECTIVE

The objective of this systematic review is to determine the tolerability and safety of psilocybin in a variety of psychiatric and substance-dependence conditions.

DATA SOURCES

A systematic review was conducted using Embase, PubMed, Cochrane Central, and Web of Science through September 2023 using the following terminology: "psilocybin" AND "mental-disease" OR "substance-dependence" AND "disease-therapy," in addition to other synonymous key words.

STUDY SELECTION AND DATA EXTRACTION

Literature reporting acute effects and safety data following the use of psilocybin as the pharmacologic intervention in a clinical trial in adult patients with a psychiatric or substance-dependence condition were included. Following the application of inclusion and exclusion criteria, 16 studies were ultimately included in this review.

DATA SYNTHESIS

The most common treatment-emergent adverse effects reported were transient nausea and headache. Transient anxiety was reported as a frequent psychiatric effect, and 3 participants received a benzodiazepine for refractory anxiety during the psilocybin session. Psilocybin demonstrated modest increases in blood pressure and heart rate, and 1 participant received an antihypertensive for sustained hypertension during the psilocybin session. No cases of psilocybin-induced psychosis or Hallucinogen Persisting Perception Disorder were reported.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

Treatment resistance remains a concern for psychiatric patients and novel therapies are needed to help alleviate the burden of morbidity and mortality. Psilocybin demonstrates promising acute and long-term safety that may allow for its use in psychiatric or substance-dependence conditions as an alternative to standards of care or in treatment-resistant patients.

CONCLUSIONS

Psilocybin has demonstrated tolerability and safety in recent literature that has investigated its therapeutic potential in a variety of psychiatric or substance-dependence conditions.

Engaging Mood Brain Circuits with Psilocybin (EMBRACE): a study protocol for a randomized, placebo-controlled and delayed-start, neuroimaging trial in depression

BACKGROUND

Major depressive disorder (MDD) is a leading cause of disability worldwide across domains of health and cognition, affecting overall quality of life. Approximately one third of individuals with depression do not fully respond to treatments (e.g., conventional antidepressants, psychotherapy) and alternative strategies are needed. Recent early phase trials suggest psilocybin may be a safe and efficacious intervention with rapid-acting antidepressant properties. Psilocybin is thought to exert therapeutic benefits by altering brain network connectivity and inducing neuroplastic changes that endure for weeks post-treatment. Although early clinical results are encouraging, psilocybin's acute neurobiological effects on neuroplasticity have not been fully investigated. We aim to examine for the first time how psilocybin acutely (intraday) and subacutely (weeks) alters functional brain networks implicated in depression.

METHODS

Fifty participants diagnosed with MDD or persistent depressive disorder (PDD) will be recruited from a tertiary mood disorders clinic and undergo 1:1 randomization into either an experimental or control arm. Participants will be given either 25 mg psilocybin or 25 mg microcrystalline cellulose (MCC) placebo for the first treatment. Three weeks later, those in the control arm will transition to receiving 25 mg psilocybin. We will investigate whether treatments are associated with changes in arterial spin labelling and blood oxygenation level-dependent contrast neuroimaging assessments at acute and subacute timepoints. Primary outcomes include testing whether psilocybin demonstrates acute changes in (1) cerebral blood flow and (2) functional brain activity in networks associated with mood regulation and depression when compared to placebo, along with changes in MADRS score over time compared to placebo. Secondary outcomes include changes across complementary clinical psychiatric, cognitive, and functional scales from baseline to final follow-up. Serum peripheral neurotrophic and inflammatory biomarkers will be collected at baseline and follow-up to examine relationships with clinical response, and neuroimaging measures.

DISCUSSION

This study will investigate the acute and additive subacute neuroplastic effects of psilocybin on brain networks affected by depression using advanced serial neuroimaging methods. Results will improve our understanding of psilocybin's antidepressant mechanisms versus placebo response and whether biological measures of brain function can provide early predictors of treatment response.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT06072898. Registered on 6 October 2023.

At the Forefront: Social Workers' Role in Psilocybin Treatment for Depression and Substance Misuse

This article underscores the critical role of social workers in harnessing the potential therapeutic benefits of psilocybin for treating major depressive disorder (MDD) and substance use disorder (SUD). Contemporary treatments for MDD often have side effects, and the success rate for SUD treatments remains low. The pervasiveness of MDD, combined with the challenges in treating SUD, highlights a need for innovative treatments. This article provides an overview of the resurgence of literature over the past two decades that illuminates the therapeutic promise of psilocybin for mental health treatment; clinical trials elucidate the efficacy of psilocybin-assisted therapy in mitigating MDD and demonstrate great promise in reducing SUD symptoms. The long-lasting posttreatment effect emphasizes its potential as a novel treatment modality. Furthermore, psilocybin's recognition as a "breakthrough therapy" by the U.S. Food and Drug Administration (FDA) and the accelerating pace of psychedelic reform bills indicate growing acceptance and interest in its therapeutic capacities. Psilocybin-assisted therapy emerges as a potent treatment option, showcasing remarkable effectiveness even after a single dose. Recommendations and pathways for social workers to be involved in psilocybin-assisted therapy investigation, advocacy, and implementation are provided.

Unlocking the healing power of psilocybin: an overview of the role of psilocybin therapy in major depressive disorder, obsessive-compulsive disorder and substance use disorder

Resistance to traditional treatment methods is still a major obstacle in modern psychiatry. As a result, several studies are currently being conducted to find effective alternatives to traditional therapies. One of these alternatives is psilocybin, a psychedelic substance that has been tested in clinical trials as an adjunct to psychotherapy. These studies focus on patients with major depressive disorder (MDD), obsessive-compulsive disorder (OCD) and substance use disorder (SUD), particularly alcohol and nicotine dependence. This article looks at the current understanding of psilocybin, including data from clinical trials conducted, psilocybin's mechanism of action, its safety and the level of risk associated with it.

Psilocybin promotes neuroplasticity and induces rapid and sustained antidepressant-like effects in mice

BACKGROUND

Psilocybin offers new hope for treating mood disorders due to its rapid and sustained antidepressant effects, as standard medications require weeks or months to exert their effects. However, the mechanisms underlying this action of psilocybin have not been identified.

AIMS

To investigate whether psilocybin has rapid and sustained antidepressant-like effects in mice and investigate whether its potential mechanisms of action are related to promoted neuroplasticity.

METHODS

We first examined the antidepressant-like effects of psilocybin in normal mice by the forced swimming test and in chronic corticosterone (CORT)-exposed mice by the sucrose preference test and novelty-suppressed feeding test. Furthermore, to explore the role of neuroplasticity in mediating the antidepressant-like effects of psilocybin, we measured structural neuroplasticity and neuroplasticity-associated protein levels in the prefrontal cortex (PFC) and hippocampus.

RESULTS

We observed that a single dose of psilocybin had rapid and sustained antidepressant-like effects in both healthy mice and chronic CORT-exposed mice. Moreover, psilocybin ameliorated chronic CORT exposure-induced inhibition of neuroplasticity in the PFC and hippocampus, including by increasing neuroplasticity (total number of dendritic branches and dendritic spine density), synaptic protein (p-GluA1, PSD95 and synapsin-1) levels, BDNF-mTOR signalling pathway activation (BDNF, TrkB and mTOR levels), and promoting neurogenesis (number of DCX-positive cells).

CONCLUSIONS

Our results demonstrate that psilocybin elicits robust, rapid and sustained antidepressant-like effects which is accompanied by the promotion of neuroplasticity in the PFC and hippocampus.

Emerging drugs in phase II and III clinical development for the treatment of alcohol use disorder

INTRODUCTION

Alcohol Use Disorder (AUD) poses an ongoing significant global health burden. AUD is highly prevalent and affects not only the individuals with AUD, but also their communities and society at large. Even though pharmacotherapy is an integral part of AUD treatment, the few available substances show limited efficacy and limited clinical impact. Thus, there is a need for new innovative pharmacotherapeutic approaches.

AREAS COVERED

This paper provides a comprehensive review of drugs approved for the treatment of AUD as well as those currently in phase II and III development. Data from recent clinical trials has been reviewed and supplemented by additional literature based on a systematic search of the PubMed database and clinical trials registries. Compounds discussed include disulfiram, naltrexone, nalmefene, acamprosat, baclofen, sodium oxybate, doxazosin, varenicline, zonisamide, gabapentin, apremilast, ibudilast, ivermectin, tolcapone, mifepristone, suvorexant, ketamine, psilocybin, semaglutide, oxytocin and cannabidiol.

EXPERT OPINION

Even though the majority of the discussed compounds lack sufficient evidence to support their efficacy, multiple promising new treatment options are currently under investigation. Future research has to consider specific phenotypes and subgroups of AUD as well as a possible enhancement of the effects of psychotherapy through combination with pharmacotherapy. Practitioners should be encouraged to use available compounds to support existing therapeutic regimens.

Deciphering psilocybin: Cytotoxicity, anti-inflammatory effects, and mechanistic insights

A decade of clinical research has indicated psilocybin's effectiveness in treating various neuropsychiatric disorders, such as depression and substance abuse. The correlation between increased pro-inflammatory cytokines and the severity of neuropsychiatric symptoms, along with the known anti-inflammatory potential of some psychedelics, suggests an immunomodulatory role for psilocybin. This study aims to understand the mechanism of action of psilocybin by investigating the cytotoxic and immunomodulatory effects of psilocybin and psilocin on both resting and LPS-activated RAW 264.7 murine macrophages. The study evaluated the cytotoxicity of psilocybin and psilocin using an LDH assay across various doses and assessed their impact on cytokine production in RAW 264.7 cells, measuring cytokine expression via ELISA. Different doses, including those above and below the LC50, were used in both pre-treatment and post-treatment approaches. The LDH assay revealed that psilocybin is almost twice as cytotoxic as psilocin, with an LC50 of 12 ng/ml and 28 ng/ml, respectively. In resting macrophages, both psilocybin and psilocin triggered significant release of TNF- α after 4 h, with the lowest doses inducing higher levels of the cytokine than the highest doses. IL-10 expression in resting cells was only triggered by the highest dose of psilocin in the 4-hour incubation group. In LPS-stimulated cells, psilocin reduced TNF- α levels more than psilocybin in pre-treatment and post-treatment, with no significant effects on IL-10 in pre-treatment. Psilocin, but not psilocybin, induced a significant increase of IL-10 in post-treatment, leading to the conclusion that psilocin, but not psilocybin, exerts anti-inflammatory effects on classically activated macrophages.

Psychedelic Therapy: A Primer for Primary Care Clinicians-Psilocybin

BACKGROUND

The primary psychoactive drug in magic mushrooms, psilocybin, induces profound alterations in consciousness through the 5-HT2A receptor. This review consolidates current research findings to elucidate the pharmacology, safety profile, and clinical applications of psilocybin.

AREAS OF UNCERTAINTY

Despite initial concerns that psilocybin could cause psychosis, contemporary research has demonstrated that psilocybin is generally safe. The most common adverse effects are nausea and headache, yet both tend to be transient. Serious adverse events can generally be avoided in controlled settings such as clinical trials. However, in the largest clinical trial to date, there were a total of 7 reported cases of suicidal ideation, up to 12 weeks after receiving a single 25 mg dose of psilocybin. That being said, all 7 cases did not respond to the treatment. Although selective serotonin reuptake inhibitors may blunt the hallucinogenic qualities of psilocybin, preliminary research suggests that they may enhance its antidepressant effects.

THERAPEUTIC ADVANCES

In clinical trials, psilocybin has shown promise for treating major depressive disorder and treatment-resistant depression. Initial studies indicated that 42%-57% of patients underwent remission after psilocybin-assisted therapy, which suggests that psilocybin is more effective than existing antidepressant medications. Clinical data have also demonstrated that psilocybin can manage substance use disorders and end-of-life anxiety with clinical outcomes that are sustained for months and sometimes years after 1 or 2 doses.

LIMITATIONS

However, larger Phase II trials with more than 100 depressed participants have shown a much smaller remission rate of 25%-29%, though these studies still observed that psilocybin causes a significant reduction in depressive symptoms.

CONCLUSIONS

Aside from ketamine, psilocybin is the most clinically well-researched psychedelic drug, with trials that have enrolled hundreds of participants and multiple therapeutic applications. Phase III trials will determine whether psilocybin lives up to the promise that it showed in previous clinical trials.

Quantification of psilocin in human whole blood using liquid chromatography-tandem mass spectrometry (LC-MS/MS)

There has been burgeoning interest in psilocybin-use for the treatment of various neurological and neurodegenerative diseases. Psilocybin is mistakenly perceived as the principal pharmacologically active compound due to its high concentrations found in magic mushrooms; however, it is the prodrug of psilocin. Despite the expanding body of clinical research seeking to understand the pharmacodynamic/pharmacokinetic properties of psilocin, and its role in inducing dramatic changes to cognitive function, there has not been a corresponding increase in the development of sensitive analytical methods that can quantify psilocin in different biological fluids. Existing analytical methods have been developed using plasma, serum, and urine as the matrix of choice, but with the unknown blood-to-plasma ratio of psilocin, any pharmacokinetic conclusions drawn solely on plasma data may be misleading. Thus, the main objective of this study is to develop the first analytical method that utilizes SPE and LC-MS/MS to quantify psilocin in human whole blood. The SPE procedure yielded a high recovery efficiency (≥89%) with minimal matrix effects. The method was validated according to ANSI/ASB 036 guidelines. Linearity was between 0.7-200 ng/mL and encompassed previously reported ranges found in plasma/serum. Bias, within- and between-run precision for all quality controls met ANSI/ASB 036 acceptability criteria. Endogenous/exogenous interferences and carryover were negligible. Psilocin stability was assessed at 4°C over 48 h and was considered stable. Although a proof-of-concept study will need to be performed to characterize the method, this analytical workflow was able to detect and quantify psilocin in human whole blood at low limits of quantification.

Potential use of psilocybin drugs in the treatment of depression

INTRODUCTION

Depression is a common disabling psychiatric disorder, which - in extreme cases - may lead to suicide if untreated or inadequately treated. Despite the availability of various treatments for depression, including pharmacotherapy, there is still a need to search for new agents with higher effectiveness and faster onset of action, especially for patients with treatment-resistant depression.

AREAS COVERED

A substance that has attracted considerable attention for nearly a decade is psilocybin, a natural psychedelic found in psilocybin mushrooms. In this study, we evaluated the efficacy and safety of psilocybin in the treatment of depression, based on pivotal randomized clinical trials. Moreover, we used findings from observational studies regarding recreational use. We also looked at ongoing clinical trials and discussed the registration status and clinical potential of the drug.

EXPERT OPINION

Clinical phase I-II trials published to date reported promising results for psilocybin in the treatment of patients with major depressive disorder and treatment-resistant depression, in a relatively short time after administration. However, before psilocybin is approved for use and administered to patients with depression, the results of large ongoing phase III clinical trials are needed to confirm its efficacy and safety and to change the way it is perceived by physicians and patients.

[Psychopharmacotherapy with the MAO-inhibitor Tranylcypromine Key Aspects and Trends in Theory and Practice]

The irreversible monoamine oxidase inhibitor tranylcypromine has been known as an antidepressant drug for more than 60 years. The aim of this review was to make an assessment of the state of the art and therapy of tranylcypromine. The recent medical-scientific literature is analyzed and discussed with respect to key aspects of and general trends in practical psychopharmacotherapy. Meta-analyses of controlled clinical studies have shown that tranylcypromine is an established approach to treatment-resistant depression. Doses (maximum dose, maintenance dose) are increasingly adapted to the requirements of treatment-resistant depression. Monoamine oxidase is not only the primary pharmacological target of tranylcypromine but determines for the first doses also the pharmacokinetics of tranylcypromine because monoamine oxidase is also an enantioselective drug-metabolizing enzyme of the monoamine oxidase inhibitor. An increased diversity of the antidepressant pharmacotherapy suggests the need to rethink the continuing assessment of tranylcypromine as a therapeutic "ultima ratio" in depression. In conclusion, tranylcypromine as a drug of second choice remains a valuable option in antidepressant treatment. Criteria of a switch from other antidepressant drugs to tranylcypromine should be better defined.

When the Trial Ends: The Case for Post-Trial Provisions in Clinical Psychedelic Research

The ethical value-and to some scholars, necessity-of providing trial patients with post-trial access (PTA) to an investigational drug has been subject to significant attention in the field of research ethics. Although no consensus has emerged, it seems clear that, in some trial contexts, various factors make PTA particularly appropriate. We outline the atypical aspects of psychedelic clinical trials that support the case for introducing the provision of PTA within research in this field, including the broader legal status of psychedelics, the nature of the researcher-therapist/participant relationship, and the extended time-frame of the full therapeutic process. As is increasingly understood, the efficacy of psychedelic-assisted psychotherapy is driven as much by extrapharmacological elements and the cultural therapeutic container as by the drug itself. As such, we also advocate for a refocusing of attention from post-trial access to a broader concept encompassing other elements of post-trial care. We provide an overview of some of the potential post-trial care provisions that may be appropriate in psychedelic clinical trials. Although the World Medical Association's Declaration of Helsinki calls on researchers, sponsors, and governments to make provisions for post-trial access, such provision may feel impracticable or out-of-reach within psychedelic trials that are already constrained by a high resource demand and significant bureaucratic burden. We show how conceiving of post-trial provision as an integral site of the research process, and an appropriate destination for research funding, will serve to develop the infrastructure necessary for the post-legalisation psychedelic medicine ecosystem.

Psilocybin-assisted therapy for depression: A systematic review and dose-response meta-analysis of human studies

Psilocybin is increasingly studied for its antidepressant effect, but its optimal dosage for depression remains unclear. We conducted a systematic review and a dose-response meta-analysis to find the optimal dosage of psilocybin to reduce depression scores. Following our protocol (CRD 42022220190) multiple electronic databases were searched from their inception until February 2023, to identify double-blind randomized placebo-controlled (RCTs) fixed-dose trials evaluating the use of psilocybin for adult patients with primary or secondary depression. A one-stage dose-response meta-analysis with restricted cubic splines was used. Cochrane risk of bias was used to assess risk of bias. Our analysis included seven studies with a total of 489 participants. Among these, four studies focused on primary depression (N = 366), including one study with patients suffering from treatment-resistant depression. The remaining three studies examined secondary depression (N = 123). The determined 95% effective doses per day (ED95) were 8.92, 24.68, and 36.08 mg/70 kg for patients with secondary depression, primary depression, and both subgroups, respectively. We observed significant dose-response associations for all curves, each plateauing at different levels, except for the bell-shaped curve observed in the case of secondary depression. Additionally, we found significant dose-response associations for various side effects, including physical discomfort, blood pressure increase, nausea/vomiting, headache/migraine, and the risk of prolonged psychosis. In conclusion, we discovered specific ED95 values for different populations, indicating higher ED95 values for treatment-resistant depression, primary depression, and secondary depression groups. Further RCTs are necessary for each population to determine the optimal dosage, allowing for maximum efficacy while minimizing side effects.

Psychedelics, With a Focus on Psilocybin: Issues for the Clinician

There has been a burgeoning interest in psychedelics among the public, state legislatures, psychiatrists and other clinical providers, and within the research community. Increasing numbers of studies evaluating psychedelics for depression, anxiety, posttraumatic stress disorder, and substance use disorders have been conducted or are underway. While discussing psychedelics in general, the focus of this paper is on psilocybin and its mechanism, how it exerts a psychedelic effect, dosing, and a review of the treatment studies of psilocybin, which were primarily for treatment-resistant depression and cancer-related anxiety. Future directions and potential limitations of studying and regulating psilocybin and other psychedelics are also discussed.

Psychedelics for treatment resistant depression: are they game changers?

INTRODUCTION

A new era of treatment for adults with treatment-resistant depression (TRD), which involves psychedelic substances, is dawning. Emerging evidence indicates that psychedelics can exert antidepressant effects through multiple neurobiological and psychological mechanisms. However, it remains to be seen if these new treatments will revolutionize the treatment of TRD.

AREAS COVERED

The present review focuses on the efficacy of serotoninergic psychedelics psilocybin, lysergic acid diethylamide (LSD), N,N-dimethyltryptamine (DMT), ayahuasca, 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT) and mescaline (3,4,5-trimethoxyphenethylamine), as well as 3,4-methylenedioxymethamphetamine (MDMA), for TRD. A systematic search was conducted for psilocybin in TRD as emerging trials had not yet been subject to review. A narrative review summarized findings on other psychedelics.

EXPERT OPINION

Psychedelic therapy has created a paradigm shift in the treatment of TRD, as it can maximize therapeutic benefits and minimize potential risks. Psilocybin holds promise as a potential game-changer in the treatment of TRD, with initial evidence suggesting a rapid antidepressant effect sustained for some responders for at least 3 months. Nevertheless, further adequately powered, double-blind, comparator-controlled trials are required to explore and clarify the mechanisms of action and long-term effects of psychedelics in TRD. Psychedelics also hold promise for other psychiatric conditions, such as bipolar depression and post-traumatic stress disorder.