A longitudinal study of hippocampal volume in first episode psychosis and chronic schizophrenia.

Brain abnormalities have been identified in patients with schizophrenia, but what is unclear is whether these changes are progressive over the course of the disorder. In this longitudinal study, hippocampal and temporal lobe volumes were measured at two time points in 30 patients with first episode psychosis (mean follow-up interval=1.9 years, range 0.54-4.18 years) and 12 with chronic schizophrenia (mean follow-up interval=2.3 years, range 1.03-4.12 years) and compared to 26 comparison subjects (mean follow-up interval 2.2 years, range 0.86-4.18 years). Hippocampal, temporal lobe, whole-brain and intracranial volumes (ICV) were estimated from high-resolution magnetic resonance images. Only whole-brain volume showed significant loss over the follow-up interval in both patient groups. The rate of this volume loss was not different in the first episode group compared to the chronic group. There were no changes in either hippocampal or temporal lobe volumes. The negative findings for the hippocampus and temporal lobes may mean that the abnormalities in these regions are stable features of schizophrenia. Alternatively, the period before the onset of frank psychotic symptoms may be the point of greatest risk for progressive change.