Symptomatic remission and hippocampus volume in schizophrenia

Objective: A recent meta-analysis of brain structure studies in schizophrenia has demonstrated that the most commonly reported deficit in brain regions was in left medial temporal lobe, which contains the hippocampus. The purpose of this study was to investigate specifically the hippocampus volume in schizophrenia with or without symptomatic remission.

Methods: Thirty-one schizophrenic patients and 31 age- and sex-matched healthy controls(HCs) were recruited. Seventeen of the patients were in symptomatic remission and 14 of them were in non-remission status. Each subject underwent magnetic resonance imaging for the measurement of the hippocampus volume using both automatic and manual methods. Symptomatic remission of schizophrenic patients was defined according to Andreasen’s remission criteria.

Results: The hippocampus volume was significantly reduced in non-remitted patients and close to significance in remitted patients compared with HCs. ANCOVA analysis showed that the major contribution to the reduction of hippocampus volume was in the head and tail but not the body of the hippocampus. Although there was no significant difference in total hippocampus volume between remission and non-remission patients, linear regression analysis showed that the reduction of left hippocampus volume can be explained by groups as well as the reduction of head volume on both sides of hippocampus.

Conclusion: Our data suggest that the left hippocampus volume, particularly in the part of head, may reflect the treatment outcome.