Asymmetry of the ventricle and age at the onset of schizophrenia

The relationship between lateral ventricular size or its asymmetry and age at the onset of schizophrenia was investigated in 20 schizophrenic patients diagnosed according to DSM-III-R criteria. The ventriclebrain ratio (VBR) was determined using three transaxial slices of magnetic resonance image (MRI) and asymmetry of the lateral ventricle was evaluated from the laterality index of the lateral ventricular area: (left-right/lef+right)×100. Each age at the onset of the prodromal and active phase according to DSM-III-R criteria was determined for each patient. The results showed that asymmetry of the ventricle, but not VBR, was significantly correlated inversely with age at the onset of both the prodromal phase and active phase. Neither asymmetry nor VBR correlated with the duration of illness, age at MRI scanning, or severity of clinical symptoms. It would thus appear that greater asymmetry of the ventricle is associated with earlier onset of schizophrenia.