But in a new study, researchers found that a single dose of psilocybin, the active ingredient in magic mushrooms, was enough to produce immediate and long-lasting increases in neuronal connections in mice.
‘We not only saw a 10 percent increase in the number of neuronal connections, but also they were on average about 10 percent larger, so the connections were stronger as well,’ said senior author and neuroscientist Alex Kwan of Yale University.
The increase in brain connections could go some way to explaining why psilocybin appears to have an antidepressant effect in some studies.
In April, a study at Imperial College London found psilocybin to be as effective as a leading antidepressant medication in a therapeutic setting.
The researchers compared the effect of psilocybin to a selective serotonin reuptake inhibitor (SSRI) in a group of 59 people with moderate to severe depression.
The results showed symptoms of depression to be reduced more quickly and effectively in the psilocybin group than the SSRI group over a six week period.
However, researchers were quick to warn at the time that the study was not large enough, or rigorous enough, to draw any sure conclusions.
While the exact effects of psilocybin are unclear, Yale researchers may have shed light on the way in which it affects the brain.
Researchers, led by neuroscientist Ling-Xiao Shao, divided a group of mice into three group. One had nothing, a second had anaesthetic ketamine (another drug found to have antidepressant benefits), and a third with psilocybin.
The mice were then scanned with a laser microscope over several days, and a month later. Mice that had been given psilocybin were found to have an increase in a brain structure called dendritic spines.
These spines are a key part of signalling for brain neurons, and play an important role in brain plasticity.
‘It was a real surprise to see such enduring changes from just one dose of psilocybin,’ said Kwan.
‘These new connections may be the structural changes the brain uses to store new experiences.’
People with depression and stress have been found to have lower levels of these spines over time – so a restoration of these structures could help mitigate some of depression’s detrimental symptoms.
Researchers found that the mice in the psilocybin group had an increase in dendritic spine density and size just 24 hours after the first dose, and that these spines persisted long after the drug had passed through their system. A month after the dose, around a third of new spines were still there.
The mice were also put through stress tests after they received their drug doses. Mice in the psilocybin group were found to cope better with mild electrical shocks, showing greater inclination and ability to escape.
Mice that received ketamine were found to have similar increases in dendritic spine density, suggesting rapid brain restructuring may play a key role in the antidepressant effects of psychoactive drugs.
MORE : Magic mushrooms as good as antidepressants says biggest study of its kind
MORE : First magic mushrooms factory found in 20 years raided by police
Get your need-to-know
latest news, feel-good stories, analysis and more
Thanks for reading the whole article. If you wish to get an daily update about Magic mushrooms could ‘rapidly restructure’ brain to beat depression , click on the bell button to subscribe for the notifications.