A seemingly healthy & socially active person can suddenly find themselves inflicted with a hideous nervous illness for no apparent reason.
What this article reveals, is the human nervous system has limitations, and is error prone in much the same way swarming ants are error prone when foraging for food. Individually ants are blind, so when foraging for food they rely on their neighbouring ants for navigation, this collective or system-wide navigation is vulnerable to a phenomenon called positive feedback i.e when the output cycle can feedback again into the input cycle causing an unexpected error in the navigation system. Interestingly this error in ant foraging behaviour is analogous to the human nervous system (ants/neurons & nest/brain). This article does a superb job of articulating that connection.
https://www.psychologytoday.com/blog/ex ... death-loop