Research library / Brain imaging study
Increased global integration in the brain after psilocybin therapy for depression
Daws RE, Timmermann C, Giribaldi B, et al. Nature Medicine 2022;28(4):844-851
This paper looked at brain scans from two psilocybin depression trials to understand how the treatment might work. In the first, people with treatment-resistant depression took psilocybin openly and were scanned before and the day after the higher dose. In the second, people with major depression were randomly assigned to psilocybin or to the antidepressant escitalopram, and scanned before and after. In both studies, people who improved on psilocybin showed brain networks becoming less separated and more connected with each other, especially networks rich in serotonin 2A receptors. Escitalopram gave a milder improvement and no such brain change. The authors propose that increased brain integration underlies psilocybin's effect, but the link is a correlation and the abstract does not report how many people were scanned.
What it found
- In both trials the antidepressant response to psilocybin was rapid and sustained
- Response correlated with reduced brain network modularity, meaning greater global integration between networks
- Networks rich in 5-HT2A receptors became more interconnected and flexible after psilocybin
- Escitalopram produced a milder response and no change in brain network organisation