Smaller brain size associated with unawareness of illness in patients with schizophrenia

Objective: Although several neuropsychological studies have supported the notion of frontal and parietal lobe involvement in unawareness of illness in schizophrenia, neuroanatomic differences have not been examined. Method: Thirty patients with schizophrenia spectrum disorder were rated by means of a structured interview assessing awareness of illness and performance on clinical rating scales. With 13 healthy comparison subjects, they underwent neuropsychological assessment and a scan using three-dimensional, spoiled gradient recall acquisition volumetric magnetic resonance imaging. Results: Patients who were relatively unaware of their illness had smaller brain and intracranial volumes (brain tissue plus CSF) than either aware patients or normal comparison subjects, who did not differ significantly from each other. Conclusions: These findings suggest that unawareness of illness is an important phenomenological feature with neurological correlates that is seen in at least one subgroup of patients with schizophrenia.