Also, as someone that actually suffers from a mental illness, the talk of madness and insanity makes me roll my eyes as it's very primitive, uninformed, and (unwittingly) reinforces some bad ideas and stigmas about mental health issues.
I always kinda wondered about that.
D&D has never dealt with insanity very well. Characters are almost never challenged that way - nobody has PTSD or whatever - unless it's some sort of "curse" or, more commonly, magical effect.
OTOH, do we want that much realism in our fantasy supers game?
To give an example (and a poor one at that), I recently cursed a couple of PC's in my Saltmarsh game. They bathed in pools devoted to Baphomet, twice willingly and once coerced through a charm, and I handed them a curse. The curse was that they were now tainted by Baphomet. The taint did not mean that their behavior had to change in any way. They were still perfectly free to do anything they wanted, except for one thing, they were not horrified by the taint, but, rather saw it as a blessing. That was the sum total of the "insanity" I inflicted on the players.
Two of the players (one who was infected and one who wasn't) absolutely lost their collective naughty word. How DARE I remove player agency. How DARE I inflict a curse without warning. On and on. To the point, where it became the straw the broke the camels back and I stopped DMing for that group. Just ruined any fun I was having. ((Note, there were other issues as well. Those are not pertinent to the discussion at hand))
But, that's the reaction of some players to the notion of adding an insanity to the characters. Absolutely refused to go with it. Hated it with a passion.
I very, very much don't have an answer here.
