Psychedelic Research Recap June 2024

Welcome back to our monthly update on psychedelic research! I’m sorry this one’s a bit late – I got married last month, so things have been busy. But I’m excited to share what’s new in this fast-changing field.

This month, we’ve got a mix of different studies to look at. We’ll see research on combining psychedelics or tweaking their chemical structure, new findings on ayahuasca, some big-picture reviews, and studies focused on single psychedelic compounds. Topics range from seizure risk and memory effects to brain connectivity changes and new treatments for depression.

We’ll also explore how psychedelic experiences can change people’s lives, whether microdosing is just a placebo effect, and the role of purging in ayahuasca healing. Other exciting areas include combining psychedelics with mindfulness, how these substances create visual effects in the brain, their impact on sleep, and new ethics guidelines for using psychedelics in healthcare. There’s a lot to dig into, so let’s get started!

This month’s recap is made possible by our supporting members.

Check out the research link overview for all the studies we didn’t add to the database.

Comparing, Combining, and Customising Psychedelics

Psychedelic research continues to push boundaries, with recent studies comparing different substances, exploring their effects on memory and brain connectivity, and developing new compounds. In this section, we’ll look at all these ‘combination’ studies.

A study compared the effects of psilocybin and 2C-B on emotional memory encoding. Both substances were found to affect memory similarly despite their different chemical structures. They impaired recollection and familiarity estimates, increased false alarms for emotional stimuli, and influenced metamemory (our understanding of our own memory). These findings suggest that different psychedelics might share common mechanisms in how they affect our memory processes. Previous research published on this study showed other similarities between the two psychedelics and noted that 2C-B could be considered a ‘lighter’ experience.

Another study used fMRI to examine how psilocybin and Salvinorin-A affect brain connectivity in non-human primates. Both substances influenced connectivity around the thalamus, claustrum, prefrontal cortex, and default mode network. However, there were also some differences between the two drugs. This research highlights the importance of the cortico-claustro-cortical network in understanding how psychedelics work in the brain.

A clinical trial tested a new form of ketamine for treating depression. This extended-release ketamine tablet (R-107) showed promising results in people with hard-to-treat depression. The highest dose (180mg) significantly improved depression symptoms compared to a placebo after 13 weeks (though this analysis was done in a small subset (n=29) of participants). Importantly, the treatment was well-tolerated, with minimal side effects like headache and dizziness.

Researchers also examined how memory might play a role in psilocybin’s therapeutic effects. They gave psilocybin along with midazolam, a (benzodiazepine) drug that impairs memory formation. They found that memory impairment was linked to less intense experiences of insight and well-being from psilocybin. This suggests that remembering the psychedelic experience might be important for its benefits.

A pilot study combined esketamine (a form of ketamine) with mindfulness training for people with alcohol problems (AUD). Esketamine seemed to help people engage more with the mindfulness practice and temporarily reduced alcohol cravings. It also led to stronger mystical and dissociative experiences compared to a placebo.

Lastly, researchers are working on developing new psychedelic-inspired compounds. A study looked at three new versions of MDMA, designed to be safer alternatives. These new compounds showed similar effects on serotonin, dopamine, and norepinephrine transporters as MDMA, but had less impact on certain serotonin receptors and were processed differently by the liver. This suggests they might have fewer side effects than MDMA while still providing therapeutic benefits.

Reviews on Safety, Efficacy, and Ethics

Recent reviews in psychedelic research have covered a range of essential topics, from safety concerns to therapeutic potential and ethical considerations. Here, we cover four that stood out (see all reviews from June/this year in our link overview).

A review examined the relationship between classic psychedelics and seizures. The study found that psychedelics may not increase seizure risk in healthy individuals or animals when used alone. However, combining psychedelics with other substances like kambo or lithium could potentially raise the risk. The authors caution that these conclusions are based on limited data and should be interpreted carefully.

Another review tackled the ongoing debate about microdosing, specifically whether its effects are mainly due to placebo. The authors analyzed dose-controlled studies of low-dose LSD and psilocybin, identifying eight potential issues that complicate the placebo explanation. These include small sample sizes, limited controlled studies, and possible selection bias. The review concludes that it’s currently unclear whether microdosing is just a placebo effect.

A comprehensive review explored the role of music in psychedelic-assisted therapy (PAT) and Indigenous entheogenic ceremonies. By examining neuroscientific, psychological, and anthropological research, the study highlighted the importance of personalized music protocols in PAT. It also suggests that integrating traditional practices from Indigenous ceremonies into modern treatment models could enhance clinical outcomes.

Lastly, a consensus statement from 27 experts identified critical ethics and policy issues for integrating psychedelic therapies into clinical practice. The statement outlines 20 points of consensus across five ethical areas, including reparations and reciprocity, informed consent, and professional boundaries. It also assigns responsibilities to relevant actors for implementing these recommendations.

Ayahuasca Studies on Purging, Healing, and Alcohol Use

Before we dive into the final group of psychedelic studies, here is a closer look at two ayahuasca studies that were published last month.

A qualitative study at the Takiwasi Centre in Peru explored practitioner perspectives on purging during ayahuasca rituals. The researchers interviewed 11 participants, including healers, plant preparers, and psychotherapists. The study identified three main explanatory models for purging: spiritual-oriented, Amazonian-oriented, and clinical-oriented. All these models emphasized the important connection between purging and healing in ayahuasca-assisted treatment for substance dependence.

Another study looked at the effects of a single dose of ayahuasca on college students with harmful alcohol use. This single-blind feasibility study involved 11 participants who received one dose of ayahuasca (70ml/70kg) along with psychological support. The researchers found a trend towards reduced alcohol consumption after the ayahuasca session, though this effect was not statistically significant after applying corrections. The ayahuasca was well-tolerated, with no serious side effects reported.

Despite these promising findings, ayahuasca remains understudied in scientific research. One major challenge is the variability in ayahuasca brews, which can differ in composition and potency depending on the plants used, preparation methods, and cultural practices. This lack of standardization makes comparing results across studies or drawing definitive conclusions difficult.

Diverse Psychedelic Studies Investigating Transformative Experiences, Visual Imagery, and Sleep Effects

Finally, let’s look at three human studies with ‘just’ one psychedelic, but with novel perspectives.

A study examining the transformative nature of psychedelic experiences interviewed 26 participants from psychedelic retreats. The results showed that psychedelics can lead to significant changes in identity, values, beliefs, and behavior. Most participants reported unique insights, and many experienced behavioral changes. The study also found that participants felt well-informed and capable when deciding to use psychedelics, with many reporting an improved ability to make changes in their lives afterward.

Another study reanalyzed data from a randomized controlled trial involving psilocybin. The researchers found that self-inhibition of visual areas in the brain leads to complex imagery experienced by participants. This aligns with existing models of how psychedelics affect brain function, highlighting how bottom-up processes are amplified under their influence.

A third study looked at how ketamine affects sleep in people with treatment-resistant depression (TRD). This secondary analysis of a randomized, double-blind, crossover trial found that ketamine impacts delta and alpha power during sleep. However, it didn’t significantly change overall sleep patterns or mediate its antidepressant and anti-suicidal effects through sleep variables.

What you can find on Blossom

Last month, we added 15 studies to the database of over 2100 research publications.

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