If you can read that and think people use this as a drug to get high, I don't know what to tell you, but I don't think pain and depression are what drug users are looking for in a high.

Hoffer back in the 50's thought people who suffered from schizophrenia did so because they could not metabolize the adrenochrome the body produces naturally. Adrenochrome is an unstable neurotoxin that the body detoxifies pretty quickly by breaking it into a harmless substance.

That's what he was testing. This is not the current thinking on schizophrenia. Which is too complex to summarize easily.

https://www.webmd.com/schizophrenia/what-causes-schizophrenia