My understanding was that being trapped in an institution with crazy people, being treated like a crazy person, stripped of your dignity, and put in isolation or force-fed medication if you try to upset the status quo or challenge your incarceration in any way is enough to drive people crazy. It certainly would me.

In this personal account, someone who on admission was merely ADHD with possible depression ends up snapping and violently beating someone: https://www.reddit.com/r/AskReddit/comments/1tdoc1/redditers...