Off-hand? Algorithm driven social media, “news” media generally, politicians, family/kids. The last is at least usually tolerable, or at least correctable. The rest should be taken only in moderation with a mound full of salt.
Powerful people. People who have the money and the power are corrupt EVERYWHERE. Yet we ignore this and move on and pay and pay and pay.
Idk what your society or definition of “insanity” is but assuming you’re asking what we believe most commonly leads to one’s mental health entering a negative feedback loop:
Broadly speaking it’s some form of hopeless desperation (yes, the hopeless qualifier matters here) that commonly kicks into high gear after falling into homelessness, at least based on my own observations
Some also get to play on hard mode simply for winning the genetic and/or socio-economic anti-lottery
So like, chronic stress?
I know it makes me crazy when I work too much. A few years of that would definitely send me over the edge.
concentration of capital and means of production in the hands of a handful of oligarchs exploiting the rest of society
Brutal school bullying from 80’s to mid 90’s and nobody giving a shit. Now we have middle aged people still broken and unable to function properly.