Magic mushrooms relieve depression and now we might know why
<p dir="ltr">Psychedelics like psilocybin, the key active ingredient in magic mushrooms, have become a beacon of hope for people with depression that is resistant to other forms of treatment - and new research has shed some light on how they affect the brain.</p>
<p dir="ltr">A team of psychedelics researchers have used MRI technology to understand how psilocybin works in the brain, finding that it first “dissolves” then expands brain connections.</p>
<p dir="ltr">The study, published in <em><a href="https://doi.org/10.1038/s41591-022-01744-z" target="_blank" rel="noopener">Nature Medicine</a></em>, found that certain parts of depressed people’s brains became more interconnected and flexible after two doses of psilocybin, and that the changes lasted for up to three weeks.</p>
<p dir="ltr">“These findings are important,” Professor David Nutt, a psychiatrist at the Imperial College London and one of the senior authors of the study, said.</p>
<p dir="ltr">“For the first time we find that psilocybin works differently from conventional antidepressants - making the brain more flexible and fluid, and less entrenched in the negative thinking patterns associated with depression.”</p>
<p dir="ltr">Though magic mushrooms have been used for their healing properties by Indigenous people for a long time, per <em><a href="https://www.sciencealert.com/scientists-have-finally-figured-out-how-magic-mushrooms-might-relieve-depression" target="_blank" rel="noopener">ScienceAlert</a></em>, their use in clinical trials - and our understanding of how they work - is limited.</p>
<p dir="ltr">Previous research from Professor Nutt and his colleagues found that a combination of psilocybin and psychological therapy was as effective as taking escitalopram, a common antidepressant, without the common side effects that can include weight gain, reduced libido, and insomnia.</p>
<p dir="ltr">Though this and other small studies have shown the benefits of psilocybin, how it works in the brain has been poorly understood until Professor Nutt’s most recent study.</p>
<p dir="ltr">He and his team analysed the brain scans of 43 people with clinical depression who had participated in two previous clinical trials, including 22 people treated with psilocybin, and 21 people who received escitalopram.</p>
<p dir="ltr">They found that those who received psilocybin had greater connectivity in regions of the brain that are rich in serotonin receptors which are usually segregated in depressed patients. A day after treatment, their brain networks were more interconnected and flexible, while no such changes were seen in the people taking the antidepressant.</p>
<p dir="ltr">“This supports our initial predictions and confirms psilocybin could be a real alternative approach to depression treatments,” Professor Nutt said.</p>
<p dir="ltr">Their findings match those of a study from 2020, which found similar changes in brain network connectivity up to a month after one dose of psilocybin.</p>
<p dir="ltr">As exciting as these findings are, neuroscientist and fellow senior author Dr Robin Carhart-Harris said more research is needed.</p>
<p dir="ltr">“We don’t know yet how long the changes in brain activity seen with psilocybin therapy last and we need to do more research to understand this,” he said.</p>
<p dir="ltr">“We do know that some people relapse, and it may be that after a while their brains revert to the rigid patterns of activity we see in depression.”</p>
<p dir="ltr">Either way, the researchers hope their findings pave the way for studying psilocybin’s effect on other mental illnesses characterised by rigid thought patterns, such as anorexia and addiction.</p>
<p dir="ltr">“We now need to test if this is the case, and if it is, then we have found something important,” Dr Carhart-Harris said.</p>
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<p dir="ltr"><em>Image: Getty Images</em></p>
