The anterior cingulate cortex (ACC) is consistently implicated in the pathophysiology of schizophrenia, and our own work has identified morphological anomalies in the ACC of people with this disorder. The aims of this study were to examine whether ACC morphological anomalies are present in a group at ultra-high risk of psychosis and whether such anomalies can be used to predict the subsequent development of a psychotic illness. Magnetic resonance imaging of 75 healthy volunteers (mean age 29.1 yrs) and 63 14-30 yr old people at ultra-high risk of developing a psychotic disorder (all right-handed males) was used to examine ACC sulcal and gyral features. Compared with the controls, significantly fewer people in the ultra-high risk group had a well-developed left paracingulate sulcus and significantly more had an interrupted left cingulate sulcus. There was no difference between those who did (n=21) and did not (n=42) subsequently develop a psychotic illness. Although ACC anomalies are present in young people considered to be at ultra-high risk of psychosis, they do not identify individuals who subsequently make the transition to psychosis. (PsycINFO Database Record (c) 2003 APA, all rights reserved). ; Using Smart Source Parsing Jun Royal College of Psychiatrists, United Kingdom Conference Proceedings/Symposia. Empirical Study. This research was partly presented at the aforementioned conference and at the Annual Meeting of the Australasian Society for Psychiatric Research (Melbourne, Australia, 2001) Peer Reviewed Journal. English