Perinatal insult as a risk factor in paranoid and nonparanoid schizophrenia

The medical histories of 30 paranoid schizophrenics were compared to those of 60 patients with nonparanoid schizophrenia. History of perinatal distress was more common in patients with chronic nonparanoid schizophrenia (p less than 0.005). A significant trend was noted for perinatal distress to be more common among cases with no family history of psychiatric illness (p less than 0.05). It is suggested that perinatal distress may be an organic risk factor for chronic nonparanoid schizophrenia and that this risk is independent of the genetic risk for this disease.