Many studies have shown that psilocybin, the active ingredient in magic mushrooms, may be helpful in treating a variety of mental illnesses, but we don’t really know what happens at the level of “functional brain networks,” the communication pathways that connect different parts of the brain.
To better understand this, researchers at Washington University School of Medicine in St. Louis repeatedly scanned the brains of seven healthy participants before, during, and after taking psilocybin. They recently published their findings in Nature.
Each study participant’s brain was scanned an average of 18 times. The scans (using fMRI, which measures changes in blood flow in the brain) showed that connections within established brain networks were disrupted, while connections between networks were strengthened. In other words, the unpredictability of normal information processing in the brain increases under the influence of psilocybin. The psychedelic brain is disrupted.
Your brain is on psilocybin. pic.twitter.com/ffIIoqtQBa
— Nicholas Fabiano, MD (@NTFbiano) July 17, 2024
There is much to be excited about in this new study. What makes it particularly novel is the rigor and high quality with which the research was conducted.
Anyone who has conducted fMRI studies knows how time-consuming and expensive they can be, not to mention the difficulty of dealing with participants who stumble. The study should also be commended for using an “active control” (stimulant medication).
Researchers found that in the days and weeks following a psychedelic experience, there are persistent brain changes in the connections between the hippocampus (the part of the brain associated with short-term memory) and the default mode network (a network of brain regions that are active when a person is at rest and not focused on the external environment).
These short-term changes may underlie psilocybin’s neuroplastic and therapeutic effects, so this research fits well with emerging interest in psychedelic treatments for anxiety, depression, and addiction.
However, because the study included only healthy volunteers, it is unclear whether the findings apply to patients who might benefit from psychotherapy with psilocybin.
Additionally, most of the findings were based on follow-up observations of only six participants (one participant dropped out of the study). Because no information was provided about these participants’ prior experience with psychedelics, there is a risk of “selection bias,” further limiting our ability to generalize these findings to the broader population.
Several other issues place additional limitations on the conclusions that can be drawn. Although the study used an active placebo, not just an inert sugar pill, no information was provided once the study began as to whether participants and researchers knew whether they had been given psilocybin or a placebo.
This is very possible, and a common problem in psychedelic research: because of psilocybin’s psychoactive effects, a double-blind procedure (where neither the researchers nor the participants know who got the real drug and who got the placebo) just doesn’t work.
This is a problem because we know from previous research that mystical-type experiences can also be caused by the placebo effect, so it’s not clear to what extent the observed differences in brain activity are due solely to the drug or are also due to participants’ beliefs and expectations about the effects of psilocybin.
Many authors report conflicts of interest. This is not a red flag in itself, but some conflicts of interest are directly related to the commercialization of neurotechnologies used in their research (such as the use of sensitive fMRI for therapeutic purposes). And it is not clear in the article how potential risk of bias was mitigated.
There are also deviations from the study protocol, i.e. its methods, main objectives, and what is reported in the article. For example, a secondary aim of the study was to measure long-term changes in participants’ well-being, as measured by the Persistent Effects Questionnaire. If these results are reported, they could tell us something about the clinical relevance of taking psilocybin. Unfortunately, however, the article does not include data on this questionnaire.
At first glance, the changes in the structure of the brain seem impressive, but it is not immediately clear what these strange images of the brain mean. What is missing from the picture is subjective data that the person evaluates himself. Only such data can help us understand what the changes in neural communication reflect.
Important questions remain: What does it mean for a person to have a brain that becomes increasingly disorganized? What is the relationship between observed changes in brain activity and how people feel about themselves and how they develop in their lives?
To answer these questions, we need to open the black box of neuroscience, for example by incorporating new techniques that allow us to bridge the gap between “objective” brain data and “subjective” human experience.
Only when the strangeness of the subjective psychedelic experience is brought back into the brain picture will we be able to say whether all these participants are really worth screening. Until then, we must be careful not to pin high hopes on desperate patients because of the persuasiveness of the color images.
Source: Port Altele
