Each narrative will either document an unbalanced person's descent into madness, or else follow somebody on the trail of a murderous psychopath. The settings are often deceptively ordinary, such as cheerful suburban homes or shabby hotels.
Horror-of-personality is a specific sub-category of horror and thriller genres; as opposed to excessive violence or the presence of malevolent supernatural beings, such stories evoke horror and/or suspense through villains who are perfectly human, but possess horrific personalities. They usually focus on Freudian psychology, as well as the cause and effect of profound insanity.