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Study explores action of ketamine as antidepressant in chronic pain

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This is Your Brain on Ketamine

Researchers at the University of Alabama, Birmingham, say the study findings demonstrate the critical role of the protein Tiam1 in the pathophysiology of chronic pain-induced mood dysregulation, and the sustained antidepressant-like effects of ketamine.

The team says they have uncovered the underlying mechanism that drives depressive systems, which acts to cause hypersensitivity in a part of the brain called the anterior cingulate cortex (ACC).

Knowledge of this mechanism identifies a potential therapeutic target for the treatment of chronic pain-induced depression, say Lingyong Li, Ph.D., and Kimberley Tolias, Ph.D., co-leaders of the research.

See also  Study measuring ketamine’s effect on brain shows promise

Published in The Journal of Clinical Investigation, the research focused on Tiam1, which modulates the activity of other proteins that help build or unbuild the cytoskeletons of cells. 

The study revealed that chronic pain in a mouse model leads to an activated Tiam1 in ACC pyramidal neurons, resulting in an increased number of spines on the neural dendrites. Dendrites are tree-like appendages attached to the body of a neuron that receive communications from other neurons.

See also  Study looks at how ketamine acts as a switch in the brain

This higher spine density increased the number of connections, and the strength of those connections, between neurons, a change known as synaptic plasticity. Those increases caused hypersensitivity and were associated with depression in the mouse model. 

Reversing the number and strength of connections in the model, by using an antagonist of Tiam1, relieved the mice of depression and diminished hypersensitivity of the neurons.

The study

To show that Tiam1 in the ACC modulates chronic pain-induced depressive-like behaviours, the researchers used molecular scissors to delete Tiam1 from the forebrain excitatory neurons of the mice. 

These mice were viable, and fertile, and displayed no gross alterations, and they still showed hypersensitivity to chronic pain. However, these Tiam1 conditional knockout mice did not display depressive- or anxiety-like behaviours in five different tests that gauge depression or anxiety.

When researchers specifically deleted Tiam1 from ACC neurons, they found the same results as the broader forebrain deletion, demonstrating that Tiam1 expressed in ACC neurons appears to specifically mediate chronic pain-induced depressive-like behaviours.

Other studies have established that an underlying cause of stress-induced depression and anxiety disorders is alterations in synaptic connections in brain regions involved in mood regulation, including the prefrontal cortex, the hippocampus and the amygdala. 

Li and Tolias found similar changes in dendritic neurons in the ACC for chronic pain-induced depressive-like behaviour — they saw a significant increase in dendritic spine density and signs of increased cytoskeleton building. 

This was accompanied by increased NMDA receptor proteins and increased amplitudes of NMDA currents in the ACC neurons, both associated with hyperactivity. These maladaptive changes were not seen in the Tiam1-knockout mice.

Researchers further showed that inhibiting Tiam1 signalling with a known inhibitor alleviated the chronic pain-induced depressive-like behaviours, without reducing the chronic pain hypersensitivity itself. 

The inhibition also normalised dendritic spine density, cytoskeleton building, NMDA receptor protein levels and NMDA current amplitudes.

Ketamine is a drug known to produce rapid and sustained antidepressant-like effects in chronic pain-induced depression, without decreasing sensory hypersensitivity. 

However, its mechanism is not fully understood. Li, Tolias and colleagues showed that ketamine’s sustained antidepressant-like effects in chronic pain are mediated, at least in part, by ketamine’s blocking the Tiam1-dependent, maladaptive synaptic plasticity in the mouse ACC neurons.

Li, an associate professor at the University of Alabama at Birmingham Department of Anesthesiology and Perioperative Medicine, stated: “Chronic pain is a major, unmet health issue that impacts the quality of life. Unfortunately, patients suffering from chronic pain have limited effective treatment options.

“Our work demonstrates the critical role Tiam1 plays in the pathophysiology of chronic pain-induced mood dysregulation and the sustained antidepressant-like effects of ketamine, revealing it as a potential therapeutic target for the treatment of comorbid mood disorders in chronic pain.”

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Is connection key? How clinicians impact patient outcomes in psychedelic therapy

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A wealth of research is showing how psychedelic-assisted therapy holds promise for the treatment of mental health conditions such as depression, but what role does the therapist play in a patient’s outcome? A new study has suggested it may be a big one.

Psychedelics have piqued huge interest due to their effects on the brain. Research points to their ability to induce neuroplasticity in the brain as one of the key reasons they may help with conditions such as depression and anxiety.

However, set – the individual’s (or patient’s) mental state – and setting – the individual’s environment during a psychedelic experience – are hugely impactful on the outcome of these experiences.

In the traditional use of psychedelic medicines, shamans help to guide set and setting throughout the experience with singing, drumming and ritual. Today, in scientific research, trials, and in clinics, the clinician is essentially playing this role.

Senior author of a new study, Alan Davis, associate professor and director of the Center for Psychedelic Drug Research and Education in The Ohio State University College of Social Work, has highlighted that the impact of clinicians on patient outcomes is not new, with research consistently showing that a trusting relationship between patients and clinicians has been key to better outcomes. This concept is known as a “therapeutic alliance”.

Understanding the therapeutic alliance

To find out more about the impact of this therapeutic alliance in psychedelic therapy, researchers from Ohio State University College of Medicine analysed data from a clinical trial that investigated psilocybin-assisted psychotherapy for the treatment of major depressive disorder (MDD).

In the trial, participants received two doses of psilocybin and 11 hours of psychotherapy, completing a therapeutic alliance questionnaire afterward, which assessed the strength of the therapist-participant relationship.

Participants also completed questionnaires about any mystical and psychologically insightful experiences they had during the drug treatment sessions. In psychedelic research, the mystical experience has often been shown to be related to the continuing positive effects of this therapy.

The Ohio team looked at the depression outcomes alongside patient reports about their experiences with the medicines as well as their connection with their therapists.

They found that a stronger relationship between patient and clinician led to a better clinical outcome for the patient – with improved depression scores up to 12 months following the experience.

Lead author Adam Levin, a psychiatry and behavioral health resident at Ohio State University College of Medicine, stated: “What persisted the most was the connection between the therapeutic alliance and long-term outcomes, which indicates the importance of a strong relationship.”

Analysis results revealed that over time, the alliance score increased, and in fact demonstrated more acute mystical experiences for the patient. The team also found that acute effects were linked to lower depression four weeks following treatment, but were not associated with better depression outcomes a year after the trial.

“The mystical experience, which is something that is most often reported as related to outcome, was not related to the depression scores at 12 months,” Davis stated.

“We’re not saying this means acute effects aren’t important – psychological insight was still predictive of improvement in the long term. But this does start to situate the importance and meaning of the therapeutic alliance alongside these more well-established effects that people talk about.”

According to the team, the analysis showed that a stronger relationship during the final therapy preparation session predicted a more mystical and psychologically insightful experience – which in turn was linked to further strengthening the therapeutic alliance.

“That’s why I think the relationship has been shown to be impactful in this analysis – because, really, the whole intervention is designed for us to establish the trust and rapport that’s needed for someone to go into an alternative consciousness safely,” Davis stated.

“This isn’t a case where we should try to fit psychedelics into the existing psychiatric paradigm – I think the paradigm should expand to include what we’re learning from psychedelics,” Levin added.

“Our concern is that any effort to minimise therapeutic support could lead to safety concerns or adverse events. And what we showed in this study is evidence for the importance of the alliance in not just preventing those types of events, but also in optimizing therapeutic outcomes.”

The authors emphasised that efforts to minimise negative experiences in future studies of psychedelics is vital, and that therapy is critical to creating a supportive environment for patients.

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Phase 2a trial to investigate 5-MeO-DMT candidate for alcohol use disorder

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Beckley Psytech and Clerkenwell Health are collaborating on a Phase 2a trial investigating Beckley’s synthetic 5-MeO-DMT candidate combined with psychological support as a treatment for alcohol use disorder (AUD).

AUD is estimated to affect around 237 million people across the globe and over 7.5 million people in the UK.

Treatment options for the harmful use of alcohol are not always effective – there are high relapse rates and there are around three million deaths each year attributed to the substance’s misuse.

Increasing research is showing that psychedelics may hold promise as innovative treatments for addiction, including substances such as ketamine and psilocybin.

See also  How psychedelics could help those living with alcohol use disorders

BPL-003 is Beckley Psytech’s short-duration and fast-acting synthetic formulation of 5-MeO-DMT – a psychedelic found in several plant species and the glands of at least one toad species – which is administered intranasally via an FDA-approved delivery device.

The compound has shown in Phase I data to be well-tolerated with a reproducible and dose-linear pharmacokinetic profile.

The Phase 2a trial

Beckley and Clerkenwell have confirmed that the collaborative Phase 2a open-label trial will evaluate the safety, tolerability and pharmacodynamic effects of a single dose of Beckley BPL-003 combined with abstinence-oriented psychological support in participants with AUD.

Currently taking place at King’s College London, Clerkenwell Health’s clinic near Harley Street, London, will provide an additional trial site.

According to Beckley, BPL-003 has been successful in eliciting psychedelic experiences of “similar intensity but shorter duration than psilocybin”.

Dr Henry Fisher, Chief Scientific Officer at Clerkenwell Health, stated: “An estimated 600,000 people are dependent on alcohol in England. This, coupled with an alarming increase in alcohol-related deaths of 89% over the past 20 years, shows the status quo isn’t working.

“Conventional treatments for alcohol dependency aren’t producing meaningful improvements and new avenues must be explored. This trial will assess whether psychedelic-assisted treatment can be an effective therapy for alcohol use disorder, with the hope of rolling out the treatment widely.

“Health professionals and policymakers should seriously consider such treatments, which could be genuinely ground-breaking for the NHS and for the hundreds of thousands of people being treated for alcohol use disorder in the UK.”

Beckley Psytech and Clerkenwell have emphasised that the results of the trial may be used to provide support for further study of psychedelic-assisted treatment for alcohol dependency.

Dr Rob Conley, Chief Medical and Scientific Officer at Beckley Psytech, added: “We’re committed to developing a transformative and effective treatment option for individuals struggling with alcohol use disorder.

“Based on our preclinical and Phase I data, we are optimistic about the potential therapeutic benefits of BPL-003 for substance use disorders and we are excited to evaluate the compound further in this clinical trial.

“I want to extend my thanks to the team at Clerkenwell Health and King’s, as well as to the patients who have joined, and will join, this study. Their participation, support and collaboration are absolutely critical to furthering research into this area of huge unmet need.”

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The Entourage Effect in Mushrooms: Natural psilocybin may outperform synthetic

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The Entourage Effect in Mushrooms: Natural psilocybin may outperform synthetic

A new study from the Hebrew University-Hadassah Medical Center has indicated that natural psilocybin extracts may demonstrate superior efficacy to synthetic psilocybin extracts.

Recent years have seen a boom in research into psilocybin for the treatment of mental health conditions such as anxiety and depression.

Many of the clinical trials investigating psilocybin use synthetic extracts rather than natural ones. This is because synthetic extracts will contain psilocybin alone, whereas natural psilocybe mushroom extracts will contain several different compounds such as psilocybin, psilocin, baeocystin and norbaeocystin.

Having multiple compounds can pose a challenge when running clinical trials as identifying which compounds are active and what their impact is becomes difficult to measure, and the concentrations of these compounds can vary depending on factors such as growth conditions and processing techniques.

This makes the standardisation of multi-compound medicines a huge challenge, as medicine consistency, reproducibility and dosing become difficult. However, these are essential factors when it comes to conducting clinical trials and receiving approval for medicines from regulators.

The Entourage Effect

In 2011 Dr Ethan Russo put forward the theory of the Entourage Effect in cannabis. 

The cannabis plant contains over 400 different cannabinoids that have so far been identified, such as THC, CBD, CBN and CBG.

Russo hypothesised that these different cannabinoid compounds work synergistically to create a therapeutic effect, as opposed to compounds such as THC or CBD working in isolation.

This hypothesis has been touched on only a few times in the scientific literature in relation to psychedelic mushrooms.

For example, in Dr Jochen Gartz’s 1989 paper ‘Biotransformation of tryptamine derivatives in mycelial cultures of Psilocybe’ which proposed a synergistic relationship between compounds in the mushrooms, and a 2015 paper by Zhuck et al, ‘Research on Acute Toxicity and the Behavioral Effects of Methanolic Extract from Psilocybin Mushrooms and Psilocin in Mice’, which observed that the effect of psychedelic mushroom extracts on mice was much stronger than pure psilocybin.

There has been very limited research on this hypothesis in mushrooms since. 

A new study: Natural may outperform synthetic

Now, a research team from Hebrew University-Hadassah Medical Center BrainLabs Center for the Psychedelic Research have compared a natural psilocybin extract to a chemically synthesised version.

Published in Molecular Psychiatry, results from the study indicate that the natural extract increased the levels of synaptic proteins associated with neuroplasticity in key brain regions, including the frontal cortex, hippocampus, amygdala, and striatum.

The ability of psilocybin to induce neuralplasticity has been indicated as one of the key features that contribute to its therapeutic effects.

The researchers suggest that these new study results indicate that nautral psilocybin extracts may offer unique therapeutic effects that may not be not achievable with synthesised, single-compound psilocybin alone. 

Metabolomic analyses also revealed that the natural extract exhibited a distinct metabolic profile associated with oxidative stress and energy production pathways.

The researchers write: “In Western medicine, there has historically been a preference for isolating active compounds rather than utilising extracts, primarily for the sake of gaining better control over dosages and anticipating known effects during treatment. The challenge with working with extracts lay in the inability, in the past, to consistently produce the exact product with a consistent compound profile. 

“Contrastingly, ancient medicinal practices, particularly those attributing therapeutic benefits to psychedelic medicine, embraced the use of extracts or entire products, such as consuming the entire mushroom. Although Western medicine has long recognised the “entourage” effect associated with whole extracts, the significance of this approach has gained recent prominence.”

However, compared to cannabis, the researchers suggest that mushroom extracts present a unique case, as they are highly influenced by their growing environment such as substrate, light exposure temperature and more.

“Despite these influences, controlled cultivation allows for the taming of mushrooms, enabling the production of a replicable extract,” the team writes.

The researchers emphasise that this research underscores the superiority of extracts with diverse compounds, and also highlights the feasibility of incorporating them into Western medicine due to the controlled nature of mushroom cultivation.

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