Academic performance in children of mothers with schizophrenia and other severe mental illness, and risk for subsequent development of psychosis: A population-based study

Abstract

Objective: We examined the academic performance at age 12 years of children of mothers diagnosed with schizophrenia or other severe mental illness using a large whole-population birth cohort born in Western Australia. We investigated the association between academic performance and the subsequent development of psychotic illness. Method: The sample comprised 3169 children of mothers with severe mental illness (schizophrenia, bipolar disorder, unipolar major depression, delusional disorder or other psychoses; ICD-9 codes 295-298), and 88 353 children of comparison mothers without known psychiatric morbidity. Academic performance of children was indexed on a mandatory state-wide test of reading, spelling, writing and numeracy. Results: A larger proportion of children (43.1%) of mothers with severe mental illness performed below the acceptable standard than the reference group (30.3%; children of mothers with no known severe mental illness). After adjusting for covariates, children of mothers with any severe mental illness were more likely than the reference group to perform below-benchmark on all domains except reading. For all children, poor spelling was associated with the later development of psychosis, but particularly for those at familial risk for severe mental illness (hazard ratio [HR] = 1.81; 95% CI for HR = 1.21, 2.72). Conclusions: Children of mothers with a severe mental illness are at increased risk for sub-standard academic achievement at age 12 years, placing these children at disadvantage for the transition to secondary school. For children with familial risk for severe mental illness, very poor spelling skills at age 12 years may be an indicator of risk for later psychotic disorder.