Neurocognitive impairments in schizophrenia: a piece of the epigenetic puzzle.

This paper is a review of studies examining the neurobehavioral antecedents of schizophrenia which flesh out neurodevelopmental models of schizophrenia by detailing the time course of the ontogeney of neurobehavioral impairments in schizophrenia. A follow back design was used to identify precursors of psychotic symptoms in children with a schizophrenic disorder. The vast majority of children with a schizophrenic disorder had significant developmental delays beginning early in life. For example, gross deficits in early language development were found in almost 80% of the schizophrenic children. Somewhat later in development impairments in fine motor and bi-manual coordination are noted. Some of these early developmental delays are transitory. For example, basic language skills are among the best preserved neurocognitive functions in children and adults with schizophrenia. The results of our cross-sectional neurocognitive studies suggest that children with schizophrenia suffer from limitations in the ability to engage in effortful cognitive processing or impairments in working memory. The links between these elementary neurocognitive impairments and the development of formal thought disorder as well as discourse deficits in children with a schizophrenic disorder will be discussed.