Pragmatic use of language by children who develop schizophrenia in adult life.

At eleven years of age all children in a UK national birth cohort wrote short stories about the life they expected to be leading at age 25. Using a data linkage exercise, we identified those who later developed schizophrenia, affective psychosis, or other non-psychotic psychiatric disorders in later life based on the PSE CATEGO diagnostic system. The majority of these had completed the written essays. Controls from the reference population were selected, matched for gender, IQ and social and economic status. The essays were scored using well established methods for assessing pragmatic use of language, namely narrative coherence and linguistic cohesion. We hypothesised that children pre-morbid for schizophrenia (Pre-Scz) would obtain low scores on all these measures. However this general hypothesis was largely disproved by the data, although some unpredicted gender effects were found. It is concluded that thought is organised in an unexceptional way in adolescents before they develop schizophrenia, once the data are corrected for any lowering of general cognitive ability in the Pre-Scz cases.