Clinical characteristics of late-onset schizophrenia and delusional disorder.

We compared 20 patients with late-onset schizophrenia, 7 with delusional disorder with hallucinations (paraphrenia), and 13 with delusional disorder without hallucinations (late-onset paranoia). We found that these three categories could be distinguished from each other on some clinical parameters. Late-onset schizophrenia was characterized by bizarre delusions; auditory hallucinations; to a lesser degree, first-rank and negative symptoms; and premorbid personality of the paranoid or schizoid type. Paraphrenia was associated with predominantly nonbizarre delusions, auditory hallucinations, earlier onset of symptoms, and paranoid or schizoid personality. Paranoia (late-onset) was characterized by late onset of symptoms, nonbizarre delusions, relatively intact premorbid personality, and an underlying physical stratum.