Psychedelic research has gone through a sort of renaissance in the last couple of years. More and more studies have investigated the potential therapeutic applications of controlled-substances such as psilocybin (the active psychoactive ingredient in 'magic mushrooms'), LSD, and MDMA, for treating PTSD, depression, anxiety, or addiction disorders. A new study suggests that the effects of psilocybin on how the brain processes emotions can last for up to a month after an initial high dose.
Most studies that examined the effects of psilocybin in the brain focused on performing fMRI scans of brain activity during the high of the trip, alongside a followup patient evaluation. While such monitoring is valuable, researchers at the Johns Hopkins University School of Medicine went the extra mile and performed brain scans on 12 volunteers when they received a high dose of psilocybin, scanning again week and one month after this administration.
In addition, the volunteers had to complete various tasks that assessed their emotional functioning and wellbeing.
According to the results published in the journal Scientific Reports, the volunteers' level of self-reported emotional distress was significantly reduced in the first week after they received psilocybin under supervision. Additionally, the brain scans showed a decrease in the amygdala's response to emotional information one week after the initial psychedelic dose.
"Acute psilocybin effects include reduced negative mood, increased positive mood, and reduced amygdala response to negative affective stimuli," the authors wrote in the study.
The amygdala represents a collection of neural cells in the brain where emotions are given meaning, remembered, and attached to our associations with them and responses to them. It is also the seat of the infamous 'fight-or-flight' response that is triggered by intense negative emotions such as fear, anxiety, aggression, and anger.
Negative affect (a broad concept that can be summarized as feelings of emotional distress) in response to facial stimuli and the amygdala response returned to baseline levels after one month. However, positive affect remained elevated, and trait anxiety was reduced even after one month.
“A single high dose of psilocybin, administered to properly screened individuals in a carefully controlled setting, can have lasting positive effects on emotional functioning in healthy individuals. These effects were reflected in transient changes in the function of brain regions that support emotional processing,” Frederick Barrett, an assistant professor and the corresponding author of the study, told PsyPost.
Due to its small sample size, it would be unwise to draw general conclusions from this study, but these preliminary results are encouraging and warrant more research. They suggest that the positive effects of psilocybin on our emotional wellbeing can be long-lasting from a single dose, which stands in stark contrast to conventional psychiatric drugs that typically require daily administration and can have severe negative side effects.
"These preliminary findings suggest that psilocybin may increase emotional and brain plasticity, and the reported findings support the hypothesis that negative affect may be a therapeutic target for psilocybin," the authors wrote.
Previously, studies showed that psilocybin resets the activity of key brain circuits linked to depression, allowing patients to feel 'defragged' or 'rebooted'. Other studies have linked the psychedelic drug to reduced anxiety and lower compulsion to pursue addictions.