A concussion is often described as a ‘mild’ traumatic brain injury. Yet repeated blows to the head rarely feel mild and the impacts – including changes in movement, memory, mood and brain function – may last for months or years.
Athletes, military personnel, people involved in vehicle collisions, older adults who experience falls and people experiencing intimate partner violence are all especially susceptible to repeated head injuries. And these are associated with an increased risk of neurodegenerative conditions, including chronic traumatic encephalopathy and Parkinson’s disease.
There is no approved drug that repairs the underlying brain damage from concussions. This therapeutic gap has prompted interest in an unconventional candidate: psilocybin, the psychoactive compound found in ‘magic mushrooms.’
New research, which I conducted with colleagues from the United States, shows that psilocybin may help the brain recover from repeated mild head trauma.
[…] Recent animal studies suggest that psilocybin may also be effective in healing repetitive brain injuries. A single dose of psilocybin administered months after repetitive concussion-like injuries improved emotional and cognitive outcomes in rats. In another study, treatment one year after a more severe brain injury improved motor function, restored serotonin-receptor signalling and reduced microglial abnormalities.
These studies suggest that psilocybin may influence both the immediate response to head injury and its long-term consequences.
[…] To further investigate the potential of psilocybin to heal concussion, our team worked with middle-aged female rats. They received one mild head impact per day for three consecutive days while awake. This approach was intended to resemble repeated concussive injuries more closely than models involving severe damage or prolonged anesthesia.
Psilocybin was administered shortly after each impact. We then combined behavioural testing, advanced magnetic resonance imaging, protein measurements and analysis of signalling fats in the blood to examine recovery from several angles.
The results were striking, although not uniformly so. Soon after injury, brain imaging revealed widespread changes consistent with vasogenic edema: fluid leakage and accumulation outside cells when the blood-brain barrier is disrupted.
Three weeks later, untreated injured rats showed abnormally strong responses of brain blood vessels to carbon dioxide, indicating persistent disruption of vascular regulation. Psilocybin partially normalized this response in several regions, including the prefrontal cortex, which supports decision-making and behavioural control.
Repeated injury also weakened the co-ordinated activity, or functional connectivity, between many brain regions. Psilocybin not only reversed this loss but produced connectivity greater than that observed in uninjured animals.
Some cautions. Results of studies in rats don’t automatically transfer over to humans. We can’t be 100 per cent sure if the results were as a result of taking psilocybin. And also the author of the article isn’t exactly neutral.
A separate experiment suggested that this “hyperconnectivity” was not simply a general effect of the drug in a healthy brain. Nevertheless, more connectivity is not necessarily better. Future work must establish whether this increase represents helpful reorganization, a temporary compensatory response or excessive network activity with its own risks.
[… ] Researchers are left with many questions: How long do the effects last? Does the treatment work when delayed? Which receptors and cell types are responsible? Will similar benefits occur in males and across different ages?
[…] What the study does provide is a particularly comprehensive demonstration that psilocybin can modify multiple biological consequences of repetitive mild head trauma when administered shortly after injury.
[…] Together with emerging animal studies showing benefits when psilocybin is administered months after brain injury, these findings suggest that psychedelics may influence both the immediate response to concussion and its longer-term consequences.
Well, here’s hoping.
In the US the use of psychedelics for the treatment of mental illness has been big news. And what’s been driving it is the mental health crisis happening there. So it’s not like everyone’s suddenly changed their minds. It’s more a case of well, nothing else is working so we may as well try it.
