Sex difference in brain structures of hippocampus and parahippocampus among patients with bipolar type I disorder / 中国神经精神疾病杂志

ABSTRACT

Objective This study aims to investigate the sex difference in the hippocampus and parahippocampus in patients with bipolar disorder. Methods We acquired T1－weighted structural MRI from 133 bipolar type I patients (60 males) and 144 normal controls (81 males). The General Linear Model was used to examine the relationship between sex and brain volumes of the hippocampus and parahippocampus, with age and intracranial volume as covariates. Results Patients showed significantly smaller volumes of the bilateral hippocampus and parahippocampus (P＜0.01). There were sex－by－diagnosis interactions in the left parahippocampus gyrus (F=6.534, P=0.044). Male patients had significant smaller volumes of the left parahippocampus gyrus compared to the male normal controls (P＜0.001) whereas the volumes were not significantly different between female patients and female normal controls (P＞0.05). Conclusion The results suggest sex difference in the left parahippocampus gyrus volume in patients with bipolar type I disorder, which deserves further investigation in the future bipolar imaging researches.