The subjects also underwent brain imaging, which measured changes in blood flow and signals transmitted between brain regions.
Immediately after the treatment, patients reported a decrease in depressive symptoms.
"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," lead author Robin Carhart-Harris said in a statement. "Several of our patients described feeling 'reset' after the treatment and often used computer analogies."
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The brain imaging also revealed reduced blood flow in areas of the brain associated with emotional responses, stress and anxiety.
"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," Carhart-Harris said.
Despite their findings, researchers said people who suffer from depression should not self-medicate.
While they hope to do more research in the future, they say their results thus far are encouraging.
“Through collecting these imaging data,” Carhart-Harris said, “we have been able to provide a window into the after effects of psilocybin treatment in the brains of patients with chronic depression.”
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