Evaluation and treatment of paranoid syndromes in the elderly: a review.

Paranoid symptoms in the elderly patient may be a manifestation of medical, neurologic, psychiatric, or medication-induced illness. Because of the potential for multiple interacting factors between underlying organicity and psychiatric illness precise assessment of the etiology of the patient's psychotic behavior may be difficult. This article reviews the medical and neurologic illnesses often associated with paranoia in the elderly as well as the psychiatric differential diagnosis. Psychotic depression, late-onset schizophrenia, and delusional/paranoid disorders are examined, as are their treatments. Revisions in the nosology of late-onset psychosis as they are affected by revisions in DSM-III-R are also discussed.