An MRI study of superior temporal gyrus volume in women with schizotypal personality disorder

Objective: An abnormal superior temporal gyrus has figured prominently in schizophrenia research, and left superior temporal gyrus volume has been shown to be smaller in male subjects with schizotypal personality disorder. This is the first structural magnetic resonance imaging study to examine a group of female subjects with schizotypal personality disorder. Method: The superior temporal gyrus was drawn on coronal images acquired from female subjects recruited from the community (schizotypal personality disorder group: N=21, comparison group: N=29). Results: There were no gray matter volume differences in the left or right superior temporal gyrus between the subjects with schizotypal personality disorder and the comparison subjects. Within the schizotypal personality disorder group, however, there was an interaction be-tween hemisphere and family history of mental illness. Moreover, subjects with schizotypal personality disorder did demonstrate formal thought disorder and a negative correlation between left superior temporal gyrus volume and odd speech. Conclusions: This study of female subjects with schizotypal personality disorder showed no superior temporal gyrus volume differences, but preliminary findings indicate that among female subjects with schizotypal personality disorder, there is a left-right difference in those who have a family history of mental illness relative to those who do not. These data also suggest an association between abnormal speech and left superior temporal gyrus volume, a finding similar to that found in schizophrenia. Results from this study thus clearly reinforce the importance of studying female subjects separately.