Developmental precursors and biological markers for schizophrenia and affective disorders: Specificity and public health implications

Schizophrenia's developmental dimension includes causes being active early in life. Precursors are manifest before psychosis begins, and there is an e merging public health agenda including prediction and prevention. We discus s the specificity of some developmental precursors to schizophrenia as an o utcome, with particular reference to longitudinal birth cohort studies. Und erlying structural brain abnormalities are considered. Differences from con trols are found in schizophrenia and, to a lesser extent, before affective disorder on many measures. This apparent lack of specificity may not be the case in neurobiological terms, as underlying mechanisms may be different; parsimony suggests not. This same lack of specificity may be an advantage i n public health terms, raising the possibility of strategies to predict and prevent a range of psychiatric disorders, not just schizophrenia.