(Media related) Can an inability to cope lead to delusions ?

[Conspirator]

I recently saw a movie (Its a Korean film called Guard Post 506 if anyone cares) about a smallpox style virus (massive sores and bumps break out on the afflicted)  that attacks a ROK army base on the DMZ. In it one of the characters actually convinces himself and many of the others that they simply don't have anything at all, they simply ignore the obvious evidence. At first I thought it was stupid, but I remembered that the mind is capable of some strange things.

I've seen trope before, there's a story by Eudora Welty I read in school where it was it least inferred that an elderly woman is seeking medicine for a grandchild has been dead for years. In another movie from the late 80's (I Think it was called By Dawn's Early Light) a character sees his family's base get nuked on a screen, he recalls the other targets getting lit up but selectively omits his own. On the last episode of MASH deals with a character that has to admit to himself that a chicken he saw strangled to death in front of him was actually a chicken.

The question I'm trying to ask is whether otherwise mentally healthy (not schizophrenic, hypnotized, on drugs, led by adults during childhood, etc.) people can suffer this kind of break with reality ?  I googled, but couldn't find anything. I asked on a different forum and they couldn't tell definitively.

[SWM]

the question is do psychologically healthy people have breaks from reality.

yes. you stated in your question "not schizophrenic" and schizophrenia is a good example to compare. the experiences that are thought of as symptoms in schizophrenia are normal experiences that are common in the general population. however with schizophrenia there may be a greater prevalence of those experiences and they cause much more distress than in the general population.

hypnosis is another good example again in hypnosis the hypnotic phenomena that are experienced are normal psychologica, physiological and emotion processes that the hypnotist essentially highjacks and uses to increase dissociation from reality.