Psilocybin for End-of-Life Anxiety Symptoms: A Systematic Review and Meta-Analysis

Exploring the role of psychedelic-assisted therapy in enhancing spirituality and mystical experiences in patients with life-threatening illnesses: A systematic review

INTRODUCTION

Psychedelic-Assisted Therapy (PAT) is gaining traction as a novel approach to addressing the psychological and existential distress experienced by patients.

OBJECTIVES

This systematic review aimed to investigate the impact of PAT on spirituality, mystical experiences, and spiritual well-being (SpWB) in patients with life-threatening, incurable, or terminal illnesses.

METHODS

A comprehensive search was conducted across PubMed, Web of Science, and Cochrane databases to identify relevant studies published between 2013 and 2023. The study population comprised patients diagnosed with life-threatening illnesses. Various forms of PAT, encompassing both typical and atypical psychedelic substances, were considered as interventions, with no specific comparators outlined. The primary outcomes of interest included spirituality, mystical experience, and SpWB. Risk of bias assessment was performed using Cochrane's tools.

RESULTS

Six studies with a high risk of bias were included in the review, all conducted in the United States of America, involving 140 patients, the majority of whom had cancer (99 %). PAT, especially with psilocybin, demonstrated significant enhancements in spirituality, mystical experiences, and SpWB. Notably, SpWB showed improvements in all studies which assessed this spiritual outcome following PAT. Mystical experiences were correlated with improvements in spirituality in one study.

CONCLUSIONS

This systematic review underscores the potential of PAT to address unmet spiritual needs and enhance SpWB in patients with life-threatening illnesses. However, further research is needed to elucidate the mechanisms underlying these therapeutic effects. Rigorous evaluation of healthcare practitioners' role in guiding patients through PAT protocols is essential to ensure safe and effective implementation in palliative care settings.

Substrate recognition by the 4-hydroxytryptamine kinase PsiK in psilocybin biosynthesis

Psilocybin, the natural hallucinogen from Psilocybe (magic) mushrooms, is a highly promising drug candidate for the treatment of depression and several other mental health conditions. Biosynthesis of psilocybin from the amino acid l-tryptophan involves four strictly sequential modifications. The third of these, ATP-dependent phosphorylation of the intermediate 4-hydroxytryptamine, is catalysed by PsiK. Here we present a crystallographic analysis and a structure-based mutagenesis study of this kinase, providing insight into its mode of substrate recognition. The results of our work will support future bioengineering efforts aimed at generating variants of psilocybin with enhanced therapeutic properties.

Neuroprotective effects of psilocybin in a rat model of stroke

BACKGROUND

Psilocybin is a psychedelic 5HT2A receptor agonist found in "magic mushrooms". Recent studies have indicated that 5HT2A agonists, such as dimethyltryptamine, given before middle cerebral artery occlusion (MCAo), improve staircase behavior, increased BDNF expression, and reduce brain infarction in stroke rats. The objective of this study is to determine the protective effect of psilocybin in cellular and animal models of stroke.

METHODS

Adult male and timed-pregnant Sprague-Dawley rats were used for this study. The neural protective effects of psilocybin were determined in primary rat cortical neurons and adult rats. Rats were subjected to a 60-min middle cerebral artery occlusion. Brain tissues were collected for histological and qRTPCR analysis.

RESULTS

Psilocybin reduced glutamate-mediated neuronal loss in rat primary cortical neuronal cultures. Psilocybin-mediated protection in culture was antagonized by the BDNF inhibitor ANA12. Pretreatment with psilocybin reduced brain infarction and neurological deficits in stroke rats. Early post-treatment with psilocybin improved locomotor behavior, upregulated the expression of MAP2 and synaptophysin, and down-regulated the expression of IBA1 in the stroke brain. ANA12 significantly attenuated psilocybin-mediated reduction in brain infarction and improvements in locomotor behavior.

CONCLUSIONS

Psilocybin reduced brain infarction and improved locomotor behavior in stroke rats; the protective mechanisms involve regulating BDNF expression. Our data support a novel therapeutic approach of psilocybin in stroke.

Less is more? A review of psilocybin microdosing

BACKGROUND

The applications of psilocybin, derived from 'magic mushrooms,' are vast, including a burgeoning practice known as microdosing, which refers to the administration of sub-hallucinogenic doses of psychedelic substances to obtain benefits without experiencing significant cognitive and perceptual distortion. However, current research is fairly new with several limitations and gaps that hinder adequate conclusions on its efficacy.

AIMS

This semi-structured review aimed to identify and highlight research gaps in the field of psilocybin microdosing for future research.

METHODS

A Preferred Reporting Items for Systematic Reviews and Meta-Analyses based strategy was employed, utilizing a chain of keywords and key phrases across multiple databases, augmented by a cross-sectional Google search for relevant grey literature in the form of the top 10 search results. A total of 40 studies and 8 unique websites were identified, summarized and tabulated into four distinct categories, namely non-clinical, clinical, observational and anecdotal evidence.

RESULTS

The majority of available evidence originates from observational studies, while non-clinical and clinical study findings remain comparatively sparse and inconsistent. Web-based findings were consistent with current research findings. Key research gaps were highlighted: the imperative for more randomized placebo-controlled trials, exploration of dose-response ranges, psychological and personality testing of participants, utilization of active placebos, greater diversity in study populations, an increase in psilocybin-exclusive microdosing studies and the refinement of animal models.

CONCLUSION

Definitive conclusions regarding the efficacy of psilocybin microdosing remain elusive, emphasizing the need for further study. Numerous research gaps necessitate consideration for future investigations.

Psilocybin for clinical indications: A scoping review

BACKGROUND

Psychedelic drugs have been of interest in medicine since the early 1950s. There has recently been a resurgence of interest in psychedelics.

AIMS

The objective of this study is to determine the extent of the available literature on psilocybin for medical indications including the designs used, study characteristics, indications studied, doses, and authors' conclusions. We identify areas for further study where there are research gaps.

METHODS

We conducted a systematic scoping review of clinical indications for psilocybin, encompassing psychiatric and medical conditions. We systematically searched Medline and Embase using keywords related to psilocybin. We reviewed titles and texts in duplicate using Covidence software. We extracted data individually in duplicate using Covidence software and a senior reviewer resolved all author conflicts. We analyzed data descriptively.

RESULTS

We included 193 published and 80 ongoing studies. Thirty-seven percent of included studies were systematic reviews. Only 12% of included studies were randomized controlled trials. The median number of participants was 22 with a median of 18 participants who had taken psilocybin. Thirty-eight percent of studies reported at least one potential conflict of interest. The most common indication was depression (28%). Also commonly studied were substance use (14%), mental health in life-threatening illness (9%), headaches (6%), depression and anxiety (6%), obsessive-compulsive disorder (3%), and anxiety disorders (3%).

CONCLUSIONS

Most studies involving the administration of psilocybin have small sample sizes and the most common focus has been psychiatric disorders. There is a need for high-quality randomized trials on psilocybin and to expand consideration to other promising indications, such as chronic pain.

Psilocybin for major depressive disorder: a systematic review of randomized controlled studies

Objectives

The purpose of this systematic review of randomized controlled trials (RCTs) was to evaluate the effectiveness, safety, and tolerability of psilocybin in adult patients with major depressive disorder (MDD).

Methods

A systematic search (up to September 14, 2023) was conducted for RCTs that examined the efficacy, safety, and tolerability of psilocybin in physically healthy adult patients with MDD. Three independent researchers extracted data from publications where the primary outcome was a change in depressive symptoms, and key secondary outcomes were changes in anxiety symptoms and suicidal ideation, discontinuation rates for any reason, and adverse drug reactions (ADRs).

Results

Five RCTs with 472 adult patients with MDD on psilocybin (n = 274) and controls (n = 198) were included. Two of the five RCTs (40%) reported mixed results, while the other three (60%) found that psilocybin had a beneficial effect on MDD treatment. Four RCTs (80%) assessing the anxiolytic effects of psilocybin for treating MDD found that psilocybin was significantly more effective than the control group in improving anxiety symptoms. Psilocybin was more effective than the control group in improving suicidal ideation in one out of five RCTs. Discontinuation rates were similar for any reason between the psilocybin group (2-13%) and the control group (4-21%) (P > 0.05). Four RCTs (80%) reported ADRs in detail. The most common ADR in both groups was headache.

Conclusion

Psilocybin was effective in improving depressive symptoms in over half of the included studies and reduced anxiety symptoms in patients with MDD. The long-term efficacy and safety of psilocybin for MDD treatment needs to be further investigated in large RCTs.

Longitudinal experiences of Canadians receiving compassionate access to psilocybin-assisted psychotherapy

Recent clinical trials have found that the serotonergic psychedelic psilocybin effectively alleviates anxiodepressive symptoms in patients with life-threatening illnesses when given in a supportive environment. These outcomes prompted Canada to establish legal pathways for therapeutic access to psilocybin, coupled with psychological support. Despite over one-hundred Canadians receiving compassionate access since 2020, there has been little examination of these 'real-world' patients. We conducted a prospective longitudinal survey which focused on Canadians who were granted Section 56 exemptions for legal psilocybin-assisted psychotherapy. Surveys assessing various symptom dimensions were conducted at baseline, two weeks following the session (endpoint), and optionally one day post-session. Participant characteristics were examined using descriptive statistics, and paired sample t-tests were used to quantify changes from baseline to the two-week post-treatment endpoint. Eight participants with Section 56 exemptions (four females, Mage = 52.3 years), all with cancer diagnoses, fully completed baseline and endpoint surveys. Significant improvements in anxiety and depression symptoms, pain, fear of COVID-19, quality of life, and spiritual well-being were observed. Attitudes towards death, medical assistance in dying, and desire for hastened death remained unchanged. While most participants found the psilocybin sessions highly meaningful, if challenging, one reported a substantial decrease in well-being due to the experience. These preliminary data are amongst the first to suggest that psilocybin-assisted psychotherapy can produce psychiatric benefits in real-world patients akin to those observed in clinical trials. Limited enrollment and individual reports of negative experiences indicate the need for formal real-world evaluation programs to surveil the ongoing expansion of legal access to psychedelics.

Methyl transfer in psilocybin biosynthesis

Psilocybin, the natural hallucinogen produced by Psilocybe ("magic") mushrooms, holds great promise for the treatment of depression and several other mental health conditions. The final step in the psilocybin biosynthetic pathway, dimethylation of the tryptophan-derived intermediate norbaeocystin, is catalysed by PsiM. Here we present atomic resolution (0.9 Å) crystal structures of PsiM trapped at various stages of its reaction cycle, providing detailed insight into the SAM-dependent methylation mechanism. Structural and phylogenetic analyses suggest that PsiM derives from epitranscriptomic N6-methyladenosine writers of the METTL16 family, which is further supported by the observation that bound substrates physicochemically mimic RNA. Inherent limitations of the ancestral monomethyltransferase scaffold hamper the efficiency of psilocybin assembly and leave PsiM incapable of catalysing trimethylation to aeruginascin. The results of our study will support bioengineering efforts aiming to create novel variants of psilocybin with improved therapeutic properties.

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.

Psychedelic Therapy: A Primer for Primary Care Clinicians-3,4-Methylenedioxy-methamphetamine (MDMA)

BACKGROUND

After becoming notorious for its use as a party drug in the 1980s, 3,4-methylenedioxy-methampetamine (MDMA), also known by its street names "molly" and "ecstasy," has emerged as a powerful treatment for post-traumatic stress disorder (PTSD).

AREAS OF UNCERTAINTY

There are extensive data about the risk profile of MDMA. However, the literature is significantly biased. Animal models demonstrating neurotoxic or adverse effects used doses well beyond the range that would be expected in humans (up to 40 mg/kg in rats compared with roughly 1-2 mg/kg in humans). Furthermore, human samples often comprise recreational users who took other substances in addition to MDMA, in uncontrolled settings.

THERAPEUTIC ADVANCES

Phase III clinical trials led by the Multidisciplinary Association for Psychedelic Studies (MAPS) have shown that MDMA-assisted psychotherapy has an effect size of d = 0.7-0.91, up to 2-3 times higher than the effect sizes of existing antidepressant treatments. 67%-71% of patients who undergo MDMA-assisted psychotherapy no longer meet the diagnostic criteria for PTSD within 18 weeks. We also describe other promising applications of MDMA-assisted psychotherapy for treating alcohol use disorder, social anxiety, and other psychiatric conditions.

LIMITATIONS

Thus far, almost all clinical trials on MDMA have been sponsored by a single organization, MAPS. More work is needed to determine whether MDMA-assisted therapy is more effective than existing nonpharmacological treatments such as cognitive behavioral therapy.

CONCLUSIONS

Phase III trials suggest that MDMA is superior to antidepressant medications for treating PTSD. Now that MAPS has officially requested the Food and Drug Administration to approve MDMA as a treatment for PTSD, legal MDMA-assisted therapy may become available as soon as 2024.

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.

Psilocybin in Palliative Care: An Update

Purpose of Review

This review article summarizes clinically and socially relevant developments over the past five years in the therapeutic use of the classical tryptamine psychedelic substance psilocybin, with respect to the common challenges faced by palliative care patients and their care teams. Psilocybin is available in whole fungal and isolated forms but is not yet approved for therapeutic use in the United States. Using targeted database and gray literature searches, and author recall, key sources were identified, reviewed, and synthesized as to the safety and efficacy of psilocybin in palliative care.

Recent Findings

Life-threatening or life-limiting illnesses and faced by palliative care patients are comorbid with emotional and spiritual distress. Research and field reports reviewed suggest that psilocybin has significant and in some cases, sustained anxiolytic, antidepressant, anti-inflammatory and entheogenic effects with a favorable safety profile. Limitations of the research include the risk for selection bias toward healthy, white, financially privileged individuals, and in general, follow-up timelines too short to appropriately evaluate durability of outcomes in psychospiritual benefits and quality of life.

Summary

While more research is needed for palliative care populations specifically, reasonable inferences can be made regarding the potential for benefit to palliative care patients from psilocybin's demonstrated anxiolytic, antidepressant, anti-inflammatory and entheogenic effects. However, major legal, ethical and financial barriers to access exist for the general population; obstacles which are likely worsened for geriatric and palliative care patients. Empiric treatment and large-scale controlled trials of psilocybin should be conducted to further investigate the findings of the smaller studies reviewed here across a variety of populations, for a greater understanding of therapeutic benefit and clinically relevant safety criteria, and to support thoughtful legalization and medical access.

Are psychedelics the answer to chronic pain: A review of current literature

AIMS

We aim to provide an evidence-based overview of the use of psychedelics in chronic pain, specifically LSD and psilocybin.

CONTENT

Chronic pain is a common and complex problem, with an unknown etiology. Psychedelics like lysergic acid diethylamide (LSD) and psilocybin, may play a role in the management of chronic pain. Through activation of the serotonin-2A (5-HT2A) receptor, several neurophysiological responses result in the disruption of functional connections in brain regions associated with chronic pain. Healthy reconnections can be made through neuroplastic effects, resulting in sustained pain relief. However, this process is not fully understood, and evidence of efficacy is limited and of low quality. In cancer and palliative related pain, the analgesic potential of psychedelics was established decades ago, and the current literature shows promising results on efficacy and safety in patients with cancer-related psychological distress. In other areas, patients suffering from severe headache disorders like migraine and cluster headache who have self-medicated with psychedelics report both acute and prophylactic efficacy of LSD and psilocybin. Randomized control trials are now being conducted to study the effects in cluster headache Furthermore, psychedelics have a generally favorable safety profile especially when compared to other analgesics like opioids. In addition, psychedelics do not have the addictive potential of opioids.

IMPLICATIONS

Given the current epidemic use of opioids, and that patients are in desperate need of an alternative treatment, it is important that further research is conducted on the efficacy of psychedelics in chronic pain conditions.

The need for establishing best practices and gold standards in psychedelic medicine

Psychedelic substances are under investigation in several drug development programs. Controlled clinical trials are providing evidence for safe and effective use of psychedelic therapies for treating mental health conditions. With the anticipated FDA approval of MDMA-assisted therapy for posttraumatic stress disorder in 2023 and psilocybin therapy for depression disorders soon after, now is the time for the medical community to become informed on best practices and to actively participate in developing standards of care for these new treatments. Given the emergence of numerous drug sponsors and other companies developing therapeutic modalities for combination with psychedelic medications, it is essential that the medical professional field is at the forefront of communicating unbiased information related to safety and effectiveness. Gold standards have long been a part of medicine and serve to distinguish treatments and assessments as the highest quality by which all others can be compared to. For a treatment to be established as a gold standard, several factors are considered including the quantity and quality of the supporting data, the rigor of trials, and the safety and efficacy compared to other treatments. In this article, we review the origins of psychedelic-assisted therapy (PAT), minimum requirements for safe use of psychedelics, criteria for gold standards in mental health, and the nuances regarding how to establish gold standards in psychedelic medicine and guide clinical decision making.

Alleviating anxiety and taming trauma: Novel pharmacotherapeutics for anxiety disorders and posttraumatic stress disorder

Psychiatric disorders associated with psychological trauma, stress and anxiety are a highly prevalent and increasing cause of morbidity worldwide. Current therapeutic approaches, including medication, are effective in alleviating symptoms of anxiety disorders and posttraumatic stress disorder (PTSD), at least in some individuals, but have unwanted side-effects and do not resolve underlying pathophysiology. After a period of stagnation, there is renewed enthusiasm from public, academic and commercial parties in designing and developing drug treatments for these disorders. Here, we aim to provide a snapshot of the current state of this field that is written for neuropharmacologists, but also practicing clinicians and the interested lay-reader. After introducing currently available drug treatments, we summarize recent/ongoing clinical assessment of novel medicines for anxiety and PTSD, grouped according to primary neurochemical targets and their potential to produce acute and/or enduring therapeutic effects. The evaluation of putative treatments targeting monoamine (including psychedelics), GABA, glutamate, cannabinoid, cholinergic and neuropeptide systems, amongst others, are discussed. We emphasize the importance of designing and clinically assessing new medications based on a firm understanding of the underlying neurobiology stemming from the rapid advances being made in neuroscience. This includes harnessing neuroplasticity to bring about lasting beneficial changes in the brain rather than - as many current medications do - produce a transient attenuation of symptoms, as exemplified by combining psychotropic/cognitive enhancing drugs with psychotherapeutic approaches. We conclude by noting some of the other emerging trends in this promising new phase of drug development.

The Effectiveness of Microdosed Psilocybin in the Treatment of Neuropsychiatric Lyme Disease: A Case Study

Lyme disease can result in severe neuropsychiatric symptoms that may be resistant to treatment. The pathogenesis of neuropsychiatric Lyme disease is associated with autoimmune induced neuroinflammation. This case report describes an immunocompetent male with serologically positive neuropsychiatric Lyme disease who did not tolerate antimicrobial or psychotropic medications and whose symptoms remitted when he began psilocybin in microdosed (sub-hallucinogenic) amounts. A literature review of its therapeutic benefits reveals that psilocybin is both serotonergic and anti-inflammatory and therefore may offer significant therapeutic benefits to patients with mental illness secondary to autoimmune inflammation. The role of microdosed psilocybin in the treatment of neuropsychiatric Lyme disease and autoimmune encephalopathies warrants further study.