The puzzle of schizophrenia: tracking the core role of cognitive deficits.

Cognitive deficits in schizophrenia are increasingly accepted as core features of this disorder that play a role as vulnerability indicators, as enduring abnormalities during clinical remission, and as critical rate-limiting factors in functional recovery. This article demonstrates the lasting influence of Norman Garmezy through his impact on one graduate student and then through his later collaborative research with colleagues. The promise of core cognitive deficits as vulnerability indicators or endophenotypes was demonstrated in research with children born to a parent with schizophrenia as well as with biological parents and siblings of individuals with schizophrenia. In studies of patients with a recent onset of schizophrenia, cognitive deficits were found to endure across psychotic and clinically remitted periods and to have a strong predictive influence on likelihood of returning successfully to work or school. Converging lines of evidence for the enduring core role of cognitive deficit in schizophrenia have led in recent years to a burgeoning interest in developing new interventions that target cognition as a means of improving functional recovery in this disorder.