Emotions and brain function are altered up to one month after a single high dose of psilocybin.
Frederick S. Barrett, Manoj K. Doss, Nathan D. Sepeda, James J Pekar, Roland R. Griffiths
Scientific Reports February 10, 2020 DOI: 10.1038/s41598-020-59282-y (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Open-label pilot study Peer reviewed |
|---|---|
| Sample size | 12 |
| Population | Healthy volunteers (7 female, 5 male) |
| Intervention | Psilocybin |
| Dose | 25 mg/70 kg |
| Duration | 1-month follow-up |
| Topics | Anxiety Neuroplasticity Psilocybin |
| Keywords | Psychedelics Mood Emotional well-being Affect Psychological health Brain changes Brain connectivity Therapeutic potential Therapy Clinical applications Medical use Mental health treatment |
| Citations | 375 |
| Key points | Psilocybin reduced negative affect and amygdala reactivity at one week, with lasting increases in positive affect and brain connectivity at one month. |
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.
In the evidence
This study is part of the evidence base for 2 syntheses in the library. Here is how each one recorded it.
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One month after a single 25 mg/70 kg dose, trait anxiety was reduced and positive affect remained elevated, though negative affect and amygdala response returned to baseline.
Synthesized
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Psilocybin reduced negative affect and amygdala reactivity at one week, with lasting increases in positive affect and brain connectivity at one month.
Synthesized
Comparable studies
Other non-randomized and open-label trials on psilocybin for anxiety, most cited first.