Cage fighter tips out still beating heart of trainer, blames mushrooms

[Major Nikon]

3. Psilocybin can cause substance induced psychosis

It very commonly produces panic attacks, and the history of the drug most certainly includes homicide, suicide, and other very unfortunate events which may be rare, but still happen.

Whether it's 'natural' or not is irrelevant. It's a drug, and like most drugs it has the potential for some very serious and unwanted side effects. It's also possible they got the wrong kind of mushroom.