FC02-01 - Risk for hospitalization for schizophrenia and affective disorders among full and half siblings of probands with schizophrenia: A population-based study

Abstract

IntroductionCompared to the general population, siblings of patients with schizophrenia have a higher risk of developing schizophrenia.ObjectivesThis study analyzed population-based data to examine the risk of hospitalization for schizophrenia and affective disorders among full vs. half siblings of patients with schizophrenia, and among persons with 1 or more siblings with schizophrenia vs. those with 2 or more.AimsThis study assessed the familial influence of schizophrenia on the development of schizophrenia and other mental disorders in siblings.MethodsThe full (n = 12,555) and half (n = 2,707) siblings of 6,115 patients with schizophrenia (ICD F20.0–20.9) were identified from the Israeli Psychiatric Hospitalization Registry. Age and gender matched controls (n = 61,048) were identified from the Israeli Population Registry. The sample's psychiatric hospitalizations were recorded from the registry.ResultsCompared to controls, risk for schizophrenia was higher among persons with one or more (OR = 9.36, 95%CI: 7.73–11.33) or 2 or more (OR = 13.76, 95%CI: 8.84–24.15) full siblings with schizophrenia. Similarly, persons with one or more (OR = 7.91, 95%CI: 5.15–12.14) or 2 or more (OR = 8.44, 95%CI: 3.57–19.94) half siblings with schizophrenia had a higher risk of schizophrenia. Similarly, risk for hospitalization for affective disorders was higher among persons with one or more (OR = 7.29 95%CI: 5.60–9.49) or 2 or more (OR = 10.25, 95%CI: 5.50–19.10) full siblings with schizophrenia.ConclusionsThis population-based study strengthens existing knowledge that schizophrenia has a strong familial, perhaps genetic component; and the greater the familial load, the greater the risk. Familial schizophrenia also increases risk for affective disorders, emphasizing the overlap between these disorders.