I haven’t read the original research report, but this writeup in the Guardian. The active ingredient of “magic mushrooms” was given to people with long term depression, who had tried both talk therapies and standard antidepressants with no effect.
Here is the critical part of the report: “Michael anxiously waited for the drug to kick in. After 50 minutes, he saw bright lights leading into the distance and embarked on a five-hour journey into his own mind, where he would re-live a range of childhood memories and confront his grief.”
If he’d been my client during those talk-therapies, he wouldn’t have needed to suffer for years until this trial. There are standard, well-researched techniques for recovering and processing traumatic childhood memories and confronting grief. I use age regression hypnosis for this, and when that’s inappropriate for some reason, Traumatic Incident Reduction. EMDR is another evidence-based technique of “exposure therapy.”
You don’t need drugs of any kind to muck around with your brain. As I have shown in From Depression to Contentment, to become mentally healthy, you need to process what seemed traumatic to you as a child.