Size abnormalities of the superior parietal cortices are related to dissociation in borderline personality disorder.

Recent evidence suggests that borderline personality disorder (BPD) is related to reduced size of the parietal lobe. Dissociative symptoms occur in the majority of individuals with BPD. Structural magnetic resonance imaging (3D-MRI) was used to assess volumes of the superior (precuneus, postcentral gyrus) and inferior parietal cortices in 30 young women with BPD who had been exposed to severe childhood sexual and physical abuse and 25 healthy control subjects. Compared with control subjects, BPD subjects had significantly smaller right-sided precuneus (-9%) volumes. The left postcentral gyrus of BPD subjects with the comorbid diagnosis of dissociative amnesia (DA) or dissociative identity disorder (DID) was significantly increased compared with controls (+13%) and compared with BPD subjects without these disorders (+11%). In BPD subjects, stronger depersonalization was significantly related to larger right precuneus size. Possibly, larger precuneus size in BPD is related to symptoms of depersonalization. Increased postcentral gyrus size in BPD may be related to the development of DA or DID in the presence of severe childhood abuse.