EFFECTS OF DIAGNOSIS, LATERALITY, AND GENDER ON BRAIN MORPHOLOGY IN SCHIZOPHRENIA

Objective: Structural neuroimaging and neuropathological studies have demonstrated a variety of aspects of brain morphology that appear to d istinguish 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 ef fects). However, findings have been inconsistent across studies, perha ps reflecting limited power due to small study group sizes. The goal o f this study was to examine diagnostic, laterality, and gender effects of brain morphology as assessed by magnetic resonance imaging in a la rge, carefully evaluated group of schizophrenic and comparison subject s. Method: One hundred two patients with schizophrenia (DSM-III-R) (70 men and 32 women) and 87 normal comparison subjects, chosen to be equ ivalent to the patients in terms of familial socioeconomic background, underwent magnetic resonance imaging with a 1.5-tesla scanner. All re gions of interest were outlined manually by an experienced technician on all slices in which they were visualized. Region of interest volume s were compared across groups, and age, sex, and stature were controll ed. Results: Schizophrenic patients were found to have larger lateral and third ventricles and smaller thalamic, hippocampal, and superior t emporal volumes than comparison subjects. No significant differences w ere 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. Conclusions: Many, but no t all, of the hypotheses informed by earlier studies regarding diagnos tic effects were confirmed, while hypotheses regarding gender and late rality interactions with diagnosis were not supported.