A pilot study published by Dr. Frederick S. Barrett has confirmed that a single dose of psilocybin can change the human brain’s neural architecture. Brain imaging techniques now show effects persisting long after a person’s experience on the drug and well beyond the substance’s half-life inside the human body.
Psilocybin is the active compound in magic mushrooms, well documented to create a lasting impression on those who take it. Early study results have been so impressive they have earned “breakthrough” status from the FDA to treat depression.
The study from John’s Hopkins Medicine published in February 2020 study is small and preliminary. Still, the results offer insight into the mechanisms around how exactly these compounds are affecting the human brain. While previous studies have shown impressive enough results to gain the FDA’s favor, scientists have admitted specific mechanisms of how the drugs work is not yet concrete. Yet now, new functional magnetic resonance imaging (fMRI) results of patients under the effects of psilocybin are mapping why psychedelics are a powerful tool to influence mental health.
The study carefully screened participants to ensure they could safely take psilocybin. Participants were prepared by trained therapists who reviewed possible effects the volunteers could experience while building a trust level necessary to guide the participants through a psychedelic experience safely.
Before taking psilocybin, healthy volunteers completed questionnaires to evaluate their mental wellbeing. An fMRI machine gathered images from how their brains reacted to negative and positive stimulation and what parts of the brain were active in a resting state.
With volunteers mentally prepared and a baseline of brain function established, the 12 volunteers took a high dose of psilocybin under two therapists’ watchful eyes. Each session lasted around 7 hours. Once complete, participants went home to rest, returning the following day to meet with their assigned therapists to discuss and understand their journeys.
One week after this experience, subjects again completed written evaluations. They underwent testing designed to stimulate positive and negative reactions while inside an MRI machine that captured brain activity images.
As researchers compared the results to the volunteer’s pre-psilocybin state, they found participants less activated by stimulation designed to trigger emotional responses. Circuits of the brain associated with reward, learning, attention, and decision making were also all stimulated. The MRI images had captured evidence of reduced amygdala activity, where lower levels of response correlate to positive increases in mood.
The study cites the effect on the amygdala as the potential therapeutic application of psilocybin. Typically, strong emotional reactions build neural pathways that reinforce ruminative thinking associated with depression and addiction. The potential of psilocybin to lessen unfavorable emotional reactions provide the opportunity to change unwanted thought patterns. It appears the period after a psilocybin session offers an opportunity for an individual to establish new habits.
The written questionnaires completed by study participants documented improved wellbeing and reduced negative moods. The results are a common post-psilocybin phenomenon, and other studies have recorded participants sustaining positive effects in days and months after psilocybin. The MRI images are now providing a concrete illustration, drawing researchers closer to understanding what specific mechanisms psychedelics active for such a profound, long-lasting effect.
At the one-month mark, participants returned for evaluation, and this time images of the subject’s brains documented the amygdala response observed at one week had returned to normal levels. Yet, the fMRI continued to map new neural connectivity across regions of the brain not previously connected before taking psilocybin. These results had been present during the one-week testing timeline and were still significant after one month.
While the researchers were not yet able to discern a specific pattern to the changes in neural connectivity, the study suggested that several weeks post-psilocybin neurological connections are more malleable. The result is evidence for the drug increasing neuroplasticity — the brain’s ability to rewire and adopt new behaviors, habits, memories, and mindset.
Lasting effects of psilocybin are documented in several other studies with MRI imaging, and conclusions are consistent. Psilocybin altering brain function is perhaps obvious from decades of individuals reporting fantastic experiences. But this newly established window into the sustained changes and increased connectivity between areas of the brain not usually connected are piquing researchers’ interest.
Again at one month, participants completed questionnaires that revealed improvements in overall wellbeing persisting, specifically highlighting an increase in ratings of conscientiousness. These results are also consistent with previous studies; it is frequent for participants to record their high dose psychedelic experiences as some of the most significant of their lives.
As documented in one study, the intensity of the experience persists over one year later. Evidence towards such profound, lasting effects is thought-provoking when combined with reported positive changes in individual quality of life. The “transformative” or “mystical” nature of the psychedelic phenomenon is a mechanism for people acquiring lasting meaning from these 8-hour experiences. Compared to current therapies or personal practices to increase one’s quality of life, it would seem psilocybin is a pathway worthy of investigation.
While psilocybin has fascinating effects, the gravity of altering the structure of one’s brain should be acknowledged. Neuroplasticity is also a mechanism with the potential to create negative patterns one does not want. Psychedelic substances can be extremely potent and are still illegal in most parts of the world. The importance of these therapies only being attempted by specially trained professionals, and only on mentally fit patients cannot be understated.
As scientists like Dr. Barrett gather images through a safe and systematic study of the how and why these compounds can change brain activity, the therapeutic potential of these substances to help society at a larger scale is much closer to being understood.