I recall someone posting that the human brain is essentially "overclocked". I don't recall if that was the phrasing but the gist was that our level of intelligence can only exist by skirting the fringes of sanity. Like some set of dynamic differential equations where, if you bump a coefficient, it spins off into chaos.

Perhaps this Brave New World, as opposed to the more agrarian one our species had been accustomed to, pushes many of us over that threshold.