Psilocybin, the active psychoactive substance found in magic mushrooms, resets the activity of key brain circuits linked to depression, British researchers report in a new study.

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The new findings were reported by researchers at Imperial College London, who compared the brain scan images of patients just before and one day after they received the psilocybin treatment under supervision. The 20 participants didn’t respond to previous alternative treatments but, this time, psilocybin seems to have done the trick.

“We have shown for the first time clear changes in brain activity in depressed people treated with psilocybin after failing to respond to conventional treatments.”

“Several of our patients described feeling ‘reset’ after the treatment and often used computer analogies. For example, one said he felt like his brain had been ‘defragged’ like a computer hard drive, and another said he felt ‘rebooted’. Psilocybin may be giving these individuals the temporary ‘kick start’ they need to break out of their depressive states and these imaging results do tentatively support a ‘reset’ analogy. Similar brain effects to these have been seen with electroconvulsive therapy.”

Each patient was first given a 10 mg dose and a follow-up 25 mg dose one week later. Two separate brain imaging methods were employed to measure changes in blood flow. Researchers were especially looking at the amygdala, the almond-shaped brain region involved in processing emotions, known to become unstable in depressed patients. Depressive symptoms were assessed through standard clinical questionnaires.

The MRI imaging showed that there was less blood flowing to the amygdala and other brain networks linked to depression. Patients told the researchers they had experienced an immediate decrease in their depressive symptoms after taking the drug. This experience seems to be consistent with decade-long anecdotal reports of the so-called ‘after-glow’ effect which characterizes an improvement in mood and stress relief.

Previous research by Imperial College London and Cardiff University showed that magic mushrooms have a significant impact on the brain. They reported consciousness-expanding effects and an activation of brain regions typically channeled during the dream state. There was also evidence to back claims that psilocybin is an ego dissolving drug, as brain activity is enhanced in the emotion system and disorganized in the part that controls ego and personality.

The researchers are careful, however, to note some important limitations regarding their study. The sample size is very small and there was no placebo group. It’s also important to mention right that the psilocybin drug was administered in a controlled setting with trained medical supervision. Researchers advise patients not to self-medicate with magic mushrooms since there’s always the risk of making things worse. Bad trips are real.

At the same time, this is just the most recent study in a body of evidence that seems to support psilocybin’s therapeutic effects against depression — often, even in those cases where patients don’t seem to respond to anything else. Psilocybin research also suggests the psychoactive compound can treat addiction and anxiety. 

“Through collecting these imaging data we have been able to provide a window into the after effects of psilocybin treatment in the brains of patients with chronic depression. Based on what we know from various brain imaging studies with psychedelics, as well as taking heed of what people say about their experiences, it may be that psychedelics do indeed ‘reset’ the brain networks associated with depression, effectively enabling them to be lifted from the depressed state,” said Dr Carhart-Harris.

Scientific reference: ‘Psilocybin for treatment-resistant depression: fMRI-measured brain mechanisms’ by Carhart-Harris, R, et al. is published in the journal Scientific Reports.