Executive dysfunction in first-episode schizophrenia and relationship to duration of untreated psychosis: the West London Study

Background Many studies have demonstrated early generalised cognitive impairment in schizophrenia. Aims To examine executive function in first-episode schizophrenia, characterise the nature of the impairment and specify any relationships with symptoms and duration of untreated psychosis (DUP). Method Patients (n=136) and normal controls (n=81) were assessed with the Cambridge Automated Neuropsychological Test Battery, National Adult ReadingTest IQ, and Scales for the Assessment of Positive and Negative Symptoms. Results Memory and executive impairments in patients were independent of IQ level. Spatial working memory was impaired because of inadequate strategy use. On a planning task, patients showed reduced planning times and suboptimal problem-solving. On an attentional set-shifting task, 75% of patients were able to perform an extra-dimensional shift thought to be a core attribute of prefrontal cortex function. Those who failed had significantly longer DUP. Conclusions Prefrontal cortex function deteriorates at the onset of psychosis and continues to worsen over time. Declaration of interest None. Funding from The Welcome Trust.