Neural correlates of executive function and working memory in the 'at-risk mental state'

Background: People with prodromal symptoms have a very high risk of developing psychosis. Aims: To use functional magnetic resonance imaging to examine the neurocognitive basis of this vulnerability. Method: Cross-sectional comparison of regional activation in individuals with an 'at-risk mental state' (at-risk group: n=17), patients with first-episode schizophreniform psychosis (psychosis group: n=10) and healthy volunteers (controls: n=15) during an overt verbal fluency task and an N-back working memory task. Results: A similar pattern of between-group differences in activation was evident across both tasks. Activation in the at-risk group was intermediate relative to that in controls and the psychosis group in the inferior frontal and anterior cingulate cortex during the verbal fluency task and in the inferior frontal, dorsolateral prefrontal and parietal cortex during the N-back task. Conclusions: The at-risk mental state is associated with abnormalities of regional brain function that are qualitatively similar to, but less severe than, those in patients who have recently presented with psychosis.