Will psilocybin lose its magic in the clinical setting?

Seeking the Psilocybiome: Psychedelics meet the microbiota-gut-brain axis

Moving towards a systems psychiatry paradigm embraces the inherent complex interactions across all levels from micro to macro and necessitates an integrated approach to treatment. Cortical 5-HT2A receptors are key primary targets for the effects of serotonergic psychedelics. However, the therapeutic mechanisms underlying psychedelic therapy are complex and traverse molecular, cellular, and network levels, under the influence of biofeedback signals from the periphery and the environment. At the interface between the individual and the environment, the gut microbiome, via the gut-brain axis, plays an important role in the unconscious parallel processing systems regulating host neurophysiology. While psychedelic and microbial signalling systems operate over different timescales, the microbiota-gut-brain (MGB) axis, as a convergence hub between multiple biofeedback systems may play a role in the preparatory phase, the acute administration phase, and the integration phase of psychedelic therapy. In keeping with an interconnected systems-based approach, this review will discuss the gut microbiome and mycobiome and pathways of the MGB axis, and then explore the potential interaction between psychedelic therapy and the MGB axis and how this might influence mechanism of action and treatment response. Finally, we will discuss the possible implications for a precision medicine-based psychedelic therapy paradigm.

Is the Requirement for First-Person Experience of Psychedelic Drugs a Justified Component of a Psychedelic Therapist's Training?

Recent research offers good reason to think that various psychedelic drugs-including psilocybin, ayahuasca, ketamine, MDMA, and LSD-may have significant therapeutic potential in the treatment of various mental health conditions, including post-traumatic stress disorder, depression, existential distress, and addiction. Although the use of psychoactive drugs, such as Diazepam or Ritalin, is well established, psychedelics arguably represent a therapeutic step change. As experiential therapies, their value would seem to lie in the subjective experiences they induce. As it is the only way for trainee psychedelic therapists to fully understand their subjective effects, some have suggested that firsthand experience of psychedelics should form part of training programs. We question this notion. First, we consider whether the epistemic benefits offered by drug-induced psychedelic experience are as unique as is supposed. We then reflect on the value it might have in regard to the training of psychedelic therapists. We conclude that, absent stronger evidence of the contribution drug-induced experiences make to the training of psychedelic therapists, requiring trainees to take psychedelic drugs does not seem ethically legitimate. However, given the potential for epistemic benefit cannot be entirely ruled out, permitting trainees who wish to gain first-hand experience of psychedelics may be permissible.

Psilocybin for Depression: From Credibility to Feasibility, What's Missing?

Psilocybin has been suggested as a promising transdiagnostic treatment strategy for a wide range of psychiatric disorders. Recent findings showed that psychedelic-assisted/"psycholitic" psychotherapy should provide significant and sustained alleviation of depressive symptoms. However, to date, there have been several study limitations (e.g., small sample sizes, blinding, limited follow-up, highly screened treatment populations) and some health/political issues, including practitioners' experience, lack of standardized protocols, psychedelics' legal status, ethical concerns, and potential psychological/psychopathological/medical untoward effects. The focus here is on a range of clinical and methodological issues, also aiming at outlining some possible suggestions. We are confident that newer evidence, more precise protocols, and eventual reclassification policies may allow a better understanding of the real potential of psilocybin as a transdiagnostic therapeutic molecule.

The modern clinical use of hallucinogens. What can we learn from the natural product research?

Can the emerging field of psychedelic research benefit from natural product research? We believe it can. In this manuscript we delineate certain topics of research with hallucinogens that directly connect with research on natural products in general.

Unraveling the Mysteries of Mental Illness With Psilocybin

Current medications have not been effective in reducing the prevalence of mental illness worldwide. The prevalence of illnesses such as treatment-resistant depression has increased despite the widespread use of a broad set of psychopharmaceuticals. Transcranial magnetic stimulation and ketamine therapy are making great strides in improving treatment-resistant depression outcomes but they have limitations. New psychotherapeutics are required that specifically target the underlying cellular pathologies leading to neuronal atrophy. This neuronal atrophy model is supplanting the long-held neurotransmitter deficit hypothesis to explain mental illness. Interest in psychedelics as therapeutic molecules to treat mental illness is experiencing a 21st-century reawakening that is on the cusp of a transformation. Psilocybin is a pro-drug, found in various naturally occurring mushrooms, that is dephosphorylated to produce psilocin, a classic tryptamine psychedelic functional as a 5-hydroxytryptamine 2A receptor agonist. We have focused this review to include studies in the last two years that suggest psilocybin promotes neuronal plasticity, which may lead to changes in brain network connectivity. Recent advancements in clinical trials using pure psilocybin in therapy suggest that it may effectively relieve the symptoms of depression in patients diagnosed with major depressive disorder and treatment-resistant depression. Sophisticated cellular and molecular experiments at the systems level have produced evidence that demonstrates psilocybin promotes neuritogenesis in the mouse brain - a mechanism that may address the root cause of depression at the cellular level. Finally, studies with psilocybin therapy for major depressive disorder suggest that this ancient molecule can promote functionally connected intrinsic networks in the human brain, resulting in durable improvements in the severity of depressive symptoms. Although further research is necessary, the prospect of using psilocybin for the treatment of mental illness is an enticing possibility.