BackgroundSeveral studies have suggested that neuropsychological and structural brain deficits are implicated in poor insight. Few insight studies however have combined neurocognitive and structural neuroanatomical measures.AimsFocusing on the ability to relabel psychotic symptoms as pathological, we examined insight, brain structure and neurocognition in first-onset psychosis.MethodVoxel-based magnetic resonance imaging data were acquired from 82 individuals with psychosis and 91 controls assessed with a brief neuropsychological test battery. Insight was measured using the Schedule for the Assessment of Insight.ResultsThe principal analysis showed reduced general neuropsychological function was linked to poor symptom relabelling ability. A subsequent between-psychosis group analysis found those with no symptom relabelling ability had significant global and regional grey matter deficits primarily located at the posterior cingulate gyrus and right precuneus/cuneus.ConclusionsThe cingulate gyrus (as part of a midline cortical system) along with right hemisphere regions may be involved in illness and symptom self-appraisal in first-onset psychosis.