Effects of diagnosis, laterality, and gender on brain morphology in schizophrenia

TLDR

Structural neuroimaging and neuropathological studies have identified diagnostic, laterality, and gender effects on brain morphology in schizophrenia, yet results are inconsistent, likely due to limited sample sizes. The study aimed to assess diagnostic, laterality, and gender effects on brain morphology using MRI in a large, well‑characterized sample of schizophrenia patients and matched controls. MRI data were acquired on a 1.5‑tesla scanner, with all regions of interest manually delineated slice‑by‑slice by an experienced technician, and volumes compared across groups while controlling for age, sex, and stature. Schizophrenia patients exhibited enlarged lateral and third ventricles and reduced thalamic, hippocampal, and superior temporal volumes, while other regional volumes and laterality or gender interactions showed no significant differences, confirming several but not all diagnostic hypotheses.

Abstract

Structural neuroimaging and neuropathological studies have demonstrated a variety of aspects of brain morphology that appear to distinguish schizophrenic patients from comparison subjects (diagnostic effects), a predominance of left-sided pathology (laterality effects), and a greater likelihood of brain abnormality among males (gender effects). However, findings have been inconsistent across studies, perhaps reflecting limited power due to small study group sizes. The goal of this study was to examine diagnostic, laterality, and gender effects of brain morphology as assessed by magnetic resonance imaging in a large, carefully evaluated group of schizophrenic and comparison subjects.One hundred two patients with schizophrenia (DSM-III-R) (70 men and 32 women) and 87 normal comparison subjects, chosen to be equivalent to the patients in terms of familial socioeconomic background, underwent magnetic resonance imaging with a 1.5-tesla scanner. All regions of interest were outlined manually by an experienced technician on all slices in which they were visualized. Region of interest volumes were compared across groups, and age, sex, and stature were controlled.Schizophrenic patients were found to have larger lateral and third ventricles and smaller thalamic, hippocampal, and superior temporal volumes than comparison subjects. No significant differences were demonstrated for intracranial, cerebral, cerebellar, temporal lobe, caudate nuclei, or temporal horn volumes. There were no significant Laterality by Diagnosis effects and no significant Gender by Diagnosis effects for any of the regions of interest.Many, but not all, of the hypotheses informed by earlier studies regarding diagnostic effects were confirmed, while hypotheses regarding gender and laterality interactions with diagnosis were not supported.