[catalogia]

> political dissidents would all wind up insane as opposed to dead in places like modern day Russia, China, etc.

I don't think it's safe to assume these regimes would favor chemically induced insanity over murder/assassination/execution. For starters, induced insanity wouldn't provide a supply of organs. For another, those in power might fear that the procedure could become reversible, or may have efficacy that wears off over time (these fears may well be ungrounded but still sufficient motivation.) This is to say, there is a finality to death that's hard to match. Furthermore, if it only works "naturally" on a small segment of the population then it's not a forgone conclusion that Putin could snap his fingers and have it weaponized such that it's effective on everybody.

Also keep in mind that inducing insanity reliably can already be done today using very primitive technology. Prolonged sensory deprivation, or even just social isolation, takes a hard toll on people. That's a pretty reliable mechanism from what I understand, and is considered a heinous form torture by many, yet these governments still choose kill people. They could also give people lobotomies or fry their brains [ab]using electroconvulsive therapy, but they still choose to kill people.