TY - JOUR T1 - ORbital frontal and amygdala volume reductions in obsessive-compulsive disorder AU - Szeszko PR, Robinson D, Alvir JJ, et al Y1 - 1999/10/01 N1 - 10.1001/archpsyc.56.10.913 JO - Archives of General Psychiatry SP - 913 EP - 919 VL - 56 IS - 10 N2 - Background  Functional neuroimaging studies have implicated the frontal lobes and the hippocampus-amygdala complex in the pathophysiology of obsessive-compulsive disorder (OCD). These brain regions have not been well investigated in patients with OCD, however, using magnetic resonance imaging.Methods  Volumes of the superior frontal gyrus, anterior cingulate gyrus, orbital frontal region, hippocampus, and amygdala were computed from contiguous magnetic resonance images in a sample of 26 patients with OCD and 26 healthy comparison subjects.Results  Patients with OCD had significantly reduced bilateral orbital frontal and amygdala volumes compared with healthy comparison subjects and lacked the normal hemispheric asymmetry of the hippocampus-amygdala complex. Neither brain structure volumes nor asymmetry indices were significantly correlated with total illness duration or length of current OCD episode.Conclusions  Findings of reduced orbital frontal and amygdala volumes in patients implicate a structural abnormality of these brain regions in the pathophysiology of OCD. Absence of the normal hemispheric asymmetry of the hippocampus-amygdala complex in patients is consistent with an anomalous neurodevelopmental process. SN - 0003-990X M3 - doi: 10.1001/archpsyc.56.10.913 UR - http://dx.doi.org/10.1001/archpsyc.56.10.913 ER -