Death and other alterations easier to model as disorders than as thought processes. Persistent intrusive thoughts, that lead to unpleasant effects - fear, obsession, major life changes around the basilisk's topic (e.g. quitting a promising math career to study theodicy). I'm on the fence on whether flashbacks of disgust or embarrassment count. Non-persistent but extreme such thoughts whose effects persist (e.g. developing a phobia or stress-induced conditions).

The stimulus has to be relatively short (a solid day of indoctrination is way too much), and to be some form of human communication - words, images and videos all count, and nothing where the medium rather than the meaning is damaging (e.g. loud noises, bright lights) does.