Psychedelic drug psilocybin shown to restore brain connections lost in depression

Updated: Aug 23


Image credit: Robina Weermeijer

The psychedelic drug psilocybin has been shown to spur the growth of neural connections lost in depression, offering hope of long-lasting treatment for the condition.


The finding comes from a study carried out by researchers at Yale University in the US which tested the drug in mice.


A single dose of the drug resulted in an immediate and lasting increase in connections between neurons – the fundamental cells in the brain and nervous system.


Specifically, the drug resulted in an increase of dendritic spines, which act as the interface between a neuron and other cells through which information passes.


This type of neural connection is known to be reduced in people with depression and chronic stress.


Using a laser-scanning microscope, researchers imaged dendritic spines in high resolution and tracked them for several days in living mice.


They found increases in the number of dendritic spines and their size within 24 hours of administration of the drug, which were still present a month later.


“We not only saw a 10% increase in the number of neuronal connections, but they were on average about 10% larger, so the connections were stronger as well,” said Alex Kwan, an associate professor of psychiatry and neuroscience and senior author of the paper.


“It was a real surprise to see such enduring changes from just one dose of psilocybin."


Read more: MDMA-assisted therapy shows promise in treating symptoms of severe PTSD

While it is still unclear exactly how compounds like psilocybin work in a human brain and how long their beneficial effects may last, they have attracted plenty of attention in recent years for their potential to treat mental health issues.


In 2019, the N-methyl-D-aspartate (NMDA) receptor antagonist esketamine was approved as a nasal spray in the US for the treatment of depression.


Similar to psilocybin's effect on mice, esketamine has an immediate impact on brain cells to relieve the symptoms of depression within hours.


The psychedelic MDMA, also known as ecstasy, is another drug that is proving useful for treating mental health issues, particularly post-traumatic stress disorder (PTSD).


In a recent study that combined MDMA medication with talking therapy, 67% of people that received the combination therapy over 18 weeks no longer qualified for a PTSD diagnosis.


Psilocybin, which is a naturally occurring compound that can be found in some mushrooms, is also currently approved in the US as part of combination therapy for treatment-resistant depression.


To read the abstract of the study, click here.


Written by Sylvie Ward

News reporter for Talking Mental Health