
Schizophrenia is a mental illness which creates a great impact on the patient and his community. The examination of the various risk factors related to the disease is important in the determination of its aetiology. The present study aimed to examine the risk factors attributed to the development of schizophrenia. A case control study method was used comparing patients with schizophrenia with control subjects. The sample of cases and their controls were collected from Al-Zahrawy hospital in Mosul city. The sample collection was for the period from 1st January to 30th of June 2000. The sample of cases includes schizophrenia patients of both sexes at all ages attending the psychiatric clinic. The sample of cases included (104) patients with schizophrenia and the control subjects were (116). The disease was significantly seen among males in the age group of less than 25 years. In the age group of (25-44) years females were more significantly affected. No sex difference was seen in the sample of patients in general as a whole. Early age of onset (less than 25 years) was more significantly seen among the males. Late onset schizophrenia affects females more than the males. Family history among parents, brothers, sisters and relatives is significantly common in the sample of cases than their controls. Early age of onset is highly statistically significantly seen if there is positive family history of schizophrenia. Preclampsia and difficult labour are highly statistically associated and strongly related to the disease development. Cesarean section has no significant association to schizophrenia. Childhood and developmental abnormalities, CNS infections and accidents are highly statistically significantly and strongly associated with schizophrenia in the present research. Stressful life events are highly statistically and strongly related to schizophrenia. Being single or divorced are highly statistically significant and strongly related to schizophrenia. Being married is inversely related to the disease. Various risk factors were highly statistically and strongly related to schizophrenia in the present study. Minor factors were either not related to the disease development like cesarean section or act as a protective factor to it, like marriage. Further investigation of these factors is needed to evaluate their role in the disease development.