Background: Hippocampal volume reduction is a well replicated finding in schizophrenia. Evidence indicates a contribution of genetic and environmental factors, especially the influence of obstetric complications to this volume reduction. The aim of this study was to compare hippocampal volume of schizophrenic patients as well as and their relatives with control subjects and to quantify the additional contribution of obstetric complications.
Methods: T1 weighted MRI brain scans of 50 schizophrenic patients, 88 first-degree relatives and 53 healthy control subjects were used to perform volumetric measurements on the left and right hippocampus. A set of clinical measures including obstetric complications were recorded for all family members.
Results: Numerically our measurements revealed a hippocampal volume reduction in schizophrenic patients (left: -14%, right: -15%) and, although less pronounced, in their unaffected relatives (left: -6%, right: -10%). Noted differences in hippocampal volume between schizophrenic patients and controls were only significant for the left side. Hippocampal volumes of patients and their relatives with obstetric complications were reduced bilaterally.
Conclusions: Hippocampal volume reduction is present in schizophrenic patients and their first-degree relatives, suggesting an influence of genetic factors. In addition, however, obstetric complications have also been shown to play a major role.