1. Severe paranoid illness without deterioration of other cognitive or affective processes.
2. The most common usage of the term today is to denote a disorder characterized by phantastic, absurd, paralogical delusions without deterioration, dementia, or loss of contact with reality except in the area of the delusional system.
3. In paranoid schizophrenia, on the other hand, there is deterioration and splitting off of many of the psychic functions, while in paranoia the delusions are so logical, at least on the surface, as to appear to be little more than an extension of the premorbid personality.