neurology... i think. jk.
cognition
cognitive
The noun form of the adjective 'mental' is mentality.
Psychologically or psychiatrically afflicted is the general term. Mental illness, sometimes called insanity or madness, refers to more serious disorders such as psychopathy or schizophrenia, while mental disorder is a general term that includes mental illness but also those disorders where there is no serious reasoning impairment. The term mental illness is used erroneously and frequently by less mature and less enlightened people to designate any mental disorder. I have 4 certifcates and a diploma in psychology and am working on another diploma.
Conflict
Off ones rocker, mental midget
neurology... i think. jk.
cognition
cognitive
Another word for pillow cover is pillowcase.
suitcase briefcaseholderboxpackreceptacle
I do not think that "mental case" is an appropriate phrase to use for any mental illness. Perhaps, in this case, "paranoid" might be a better word here. The answer, I suppose, depends on whether people are actually gossiping (or giving an impression so that a reasonable person would infer they are gossiping) about that person!
A book case?
The word "personality" can be a person's characteristics, or another word for a celebrity.(* the rarely used word "presenility" means premature mental debility)
farts
no mental in the word governmental is just a conjunction