Emotions and brain function are altered up to one month after a single high dose of psilocybin.
Scientific reports – February 10, 2020
Source: PubMed
Summary
A single psilocybin dose can elevate positive mood for a full month. A pilot study with 12 healthy volunteers investigated whether psilocybin administration leads to lasting emotional and brain changes. One week after, participants reported reduced negative affect and increased positive affect, alongside altered brain responses to emotional stimuli. Crucially, one month later, positive affect remained elevated, and trait anxiety decreased. Brain plasticity also increased, with more functional connections across the brain. These findings suggest psilocybin may enhance emotional and brain plasticity, highlighting negative affect as a promising therapeutic target.
Abstract
Psilocybin is a classic psychedelic compound that may have efficacy for the treatment of mood and substance use disorders. Acute psilocybin effects include reduced negative mood, increased positive mood, and reduced amygdala response to negative affective stimuli. However, no study has investigated the long-term, enduring impact of psilocybin on negative affect and associated brain function. Twelve healthy volunteers (7F/5M) completed an open-label pilot study including assessments 1-day before, 1-week after, and 1-month after receiving a 25 mg/70 kg dose of psilocybin to test the hypothesis that psilocybin administration leads to enduring changes in affect and neural correlates of affect. One-week post-psilocybin, negative affect and amygdala response to facial affect stimuli were reduced, whereas positive affect and dorsal lateral prefrontal and medial orbitofrontal cortex responses to emotionally-conflicting stimuli were increased. One-month post-psilocybin, negative affective and amygdala response to facial affect stimuli returned to baseline levels while positive affect remained elevated, and trait anxiety was reduced. Finally, the number of significant resting-state functional connections across the brain increased from baseline to 1-week and 1-month post-psilocybin. 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.