Psychedelic Research Recap October 2025

Welcome back to our monthly update on psychedelic research!

October 2025 was a calm month for psychedelic research. Whilst we saw record investments, there was a significant dip in research that was published. In our recap, we look back at an fMRI study on emotional reactivity in psychedelic users, another null result for microdosing for cognitive enhancement, and the importance of set and setting in psychedelic treatments.

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.

October’s Randomised Trials

We start with highlights of the latest randomised, placebo-controlled trials testing psychedelic compounds in people. The studies look at both new drugs and well-known ones, using careful methods to measure safety, mental effects, and biology.

The first pair of trials tested whether microdosing psilocybin truffles could sharpen thinking, boost mood, or improve social functioning in healthy people. Over several weeks, volunteers took tiny doses, or a placebo, then completed a mix of tasks and surveys. No clear cognitive or emotional benefits turned up for microdosing, apart from some physical sensations like alertness or mild nausea in those who took the active truffles. Both groups reported mostly positive experiences, suggesting that expectation or context played a big role. These results challenge the idea that microdosing psilocybin leads to real-world gains in a healthy population.

Another trial introduced GM-2505, a new short-acting psychedelic meant for supervised use in therapy. Like the psilocybin studies, it used a double-blind, placebo-controlled setup with healthy volunteers. GM-2505 produced the expected psychedelic effects and brainwave changes, but with a time window shorter than psilocybin and longer than DMT. Side effects were mild and faded quickly. This kind of profile may be helpful for therapy sessions that need a predictable start and finish.

The next RCT study focused on psilocybin’s effects on the brain’s synaptic density, a marker for neuroplasticity. Again, a placebo-controlled design was used, but the researchers split participants into two groups: one received psilocybin in a supportive room, the other in an MRI scanner. The setting made a clear difference. Only those dosed in the calm, supportive room showed bigger increases in synaptic density and stronger, more positive experiences. This matches findings from the earlier studies—context matters, not just the drug or the dose. It also hints that the environment could shape long-term brain changes after psychedelics.

A final study compared two stimulants: methamphetamine and MDMA. In a crossover trial, volunteers received each drug and a placebo on different days. Methamphetamine, but not MDMA, lowered blood levels of a key endocannabinoid (2-AG), a chemical linked to stress and reward. Both drugs raised heart rate and stress hormones, but the differences in endocannabinoid response suggest unique biological effects for each drug, despite some similarities in how people feel on them. Just like the earlier studies, this trial shows that close design and direct comparison can reveal where drugs overlap and where they differ.

Therapeutic Context and Lasting Impact of Psychedelics

This section looks at how psychedelics affect emotional processing, what makes therapy work, and which factors might lead to better outcomes. The studies use brain imaging, interviews, and clinical follow-up to understand not just the drugs themselves, but the people and settings involved.

The first (pre-print) study used brain scans to compare people with at least ten psychedelic experiences to non-users. Experienced users were faster and more accurate at spotting angry faces and showed less activity in brain regions tied to threat. They also had stronger responses to happiness and less rigid separation between different emotions in self-focused brain regions. These effects might reflect longer-lasting changes in emotional processing that appear after repeated psychedelic use.

A second study interviewed people who received psilocybin therapy for cancer-related depression (see this earlier study). Those who were able to accept and let go during intense moments, and who felt safe and supported, were more likely to benefit. Preparation, therapist presence, music, and even small ritual touches all mattered. The hardest moments often led to the greatest healing, but only when people trusted the environment and those around them.

The final study gave psilocybin therapy to people with depression who had not improved with other treatments. Most participants saw their symptoms improve in the weeks after two sessions, though some relapsed or did not respond. People who went in with a better mindset or had spiritual or meaningful experiences were more likely to get better. Expectations alone did not predict who improved. A few participants needed extra support, highlighting the need for strong preparation and careful follow-up.

Taken together, these studies suggest that psychedelics can shape emotional processing and offer help for depression, but outcomes rely on much more than the drug alone. Preparation, support, and a safe setting are key to real change.

What you can find on Blossom

Last month, we added seven studies to the database of over 2250 research publications. Our link overview provides links to 140 psychedelic studies published in October 2025.

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