In October 2014, an international team of researchers (including two of the authors who led the present study) looked at psilocybin’s effect on the brain by comparing fMRI scans of people injected with 2 milligrams of the drug with people injected with 2 milligrams of a placebo.

Typically, brain activity follows specific neural networks, like traffic on congested highway routes. But in the people given the psilocybin injections, cross-brain activity appeared more erratic, as if someone gave all the cars on the highway 4-wheel-drive and let them steer wherever they wanted.

But looking closer, the researchers found the new activity wasn’t chaotic either — it formed distinct patterns, or cycles — new information highways, essentially.

“The brain does not simply become a random system after psilocybin injection,” the researchers wrote, “but instead retains some organizational features, albeit different from the normal state.”

Here’s a visualization of the brain connections in the brain of a normal person (a) next to someone dosed with psilocybin (b):

In essence, the researchers found that the psilocybin appeared to effectively sprout new links across previously disconnected brain regions, temporarily altering the brain’s entire organizational framework.

These new connections are likely what allow users to experience things like seeing sounds or hearing colors. And they could also be responsible for giving magic mushrooms some of their antidepressant qualities, the researchers suggested in 2014.

Another study done two years earlier by one of the same neuroscientists who worked on these two papers — Imperial College London neuroscientist David Nutt — helped him draw similar conclusions.

In 2012, Nutt found that in people drugged with psilocybin, brain chatter across traditional areas of the brain was muted, including in a region thought to play a role in maintaining our sense of self.

In depressed people, Nutt believes, the connections between brain circuits in this sense-of-self region may be too strong. “People who get into depressive thinking, their brains are overconnected,” Nutt told Psychology Today. This is what allows negative thoughts and feelings of self-criticism to perhaps become obsessive and overwhelming. So loosening those connections and creating new ones, Nutt thinks, could provide intense relief.

For their small pilot study of just 12 people with severe depression whose illness didn’t respond to any other treatments, researchers gave everyone in the group 10 milligrams of psilocybin in capsule form to swallow (during week one) and 25 milligrams (during week two), alongside several other forms of supportive therapy — including being brought into a treatment room and consulting with a psychiatrist. All of the patients reported some decrease in depressive symptoms for at least three weeks following their treatment. And three months later, seven people continued to see fewer symptoms of depression. Of those seven, five remained in remission — meaning their severe depressive symptoms did not return — after the three months.

Exciting news for psilocybin.

Source: How magic mushrooms might be used to treat depression – Business Insider

And to go with this story, here’s some intoxicating imagery: