He had a severe benzo addiction and rather than going through the normal treatment of tapering off use, he opted for an experimental treatment offered in Russia where he was instead placed in a medically induced coma to avoid the worst of the withdrawals. This had other side effects though and he later described having to relearn basic motor functions after being awoken, so who knows what else that did to him.
I think anyone who puts themselves into a coma because it’s easier than fighting addiction has no room to scold me on my life choices, he was always stupid.
I know addiction is hard to beat and I’m not trying to be insensitive, it’s not as easy as “Just stop doing drugs”
But if you take irresponsibily stupid shortcuts in life… You can stop trying to be my Guru