Self-reported mental health difficulties and subsequent risk for schizophrenia in females: A 5-year follow-up cohort study

Background: Patients with schizophrenia often report a history of premorbid mild to severe psychological distress. We investigated the association between self-reported mental health difficulties and later psychiatric hospitalization for schizophrenia. Methods: 13,357 females aged 17, mandatory assessed by the Israeli Draft Board were followed up over 5 years for psychiatric hospitalization by means of the Israeli National Psychiatric Hospitalization Case Registry. Seventeen females, judged healthy at Draft Board assessment, were hospitalized for schizophrenia or schizoaffective disorder over the follow-up period. Results: There was a significant monotonic association between increasing self-reported mental health difficulties (psychological distress and increasing need for psychological counseling) and prevalence of schizophrenia [odds ratios over four levels: 1.56; 95%CI:1.04 to 2.34; χ² (1) = 4.62, p = 0.03], after controlling for low IQ, immigration, SES, and presence of psychiatric disorders at age 17. Increasing severity of self-reported mental health difficulties was related to earlier age of first hospitalization [r = - 0.48, p = 0.05]. Conclusions: Increased undifferentiated self-reported mental health difficulties are associated with increased risk of later hospitalization for schizophrenia prior to age 23 in females. This may reflect the prodromal phase of the illness.