Suzanne Yang, MD

The term “paranoia,” derived from the Greek &lduo;para” (beside) and “nous” (mind), was coined as a descriptor of psychopathology by Heinroth in 1818.1 By the end of the 19th century, 50% to 80% of patients in asylums in German-speaking coun­tries had received a diagnosis of paranoia.1 Beginning in 1899, Kraepelin’s efforts to define paranoia more precisely resulted in a decrease in diagnoses of paranoia in favor of dementia praecox and, later, schizophrenia.1,2 This narrowing of the definition of paranoia is reflected in current nosology and practice. In DSM-IV-TR, the prevalence of delusional disorder is estimated at 0.03% of the general population and accounts for 1% to 2% of psychiatric admissions. The prevalence of paranoid personality disorder is 0.5% to 2.5%; this condition accounts for 10% to 30% of psychiatric admissions.3