A preliminary observation of resting-state functional connectivity of bilateral amygdale in drug-naive patients with obsessive-compulsive disorder

Objective To explore the pattern of resting-state functional connectivity of bilateral amygdale in drug-naive obsessive-compulsive disorder (OCD). Methods Forty patients with OCD matched the criteria of International Classification of Diseases-10 and 38 gender-, age-, education-matched healthy subjects participated in the resting-state brain functional magnetic resonance imaging scan. The Yale-Brown Obsessive-Compulsive Scale, 17-Hamilton Depression Rating Scale and Hamilton Anxiety Rating Scale (HAMA) were used to assess the clinical symptoms of obsession, compulsion, depression and anxiety. Based on the Data Processing & Analysis for (Resting-State) Brain Imaging software, a voxel-based functional connectivity approach was used to explore the pattern of resting-state functional connectivity of bilateral amygdala in OCD; Pearson correlation analyses was used to analyze the relationship between the abnormal functional connectivity values and clinical symptoms in OCD. Results Compared with the controls, patients with OCD showed decreased functional connectivity values between left amygdale and right dorsal anterior insula (0.16±0.13 vs. 0.27±0.13, t=-2.75, P<0.05, Gaussian random field (GRF) corrected, two-tailed), and between left amygdale and left ventral anterior cingulate cortex (0.09±0.12 vs. 0.19±0.13, t=-3.40, P<0.05, GRF corrected, two-tailed). The functional connectivity between left amygdale and right dorsal anterior insula was positively correlated with HAMA total score (r=0.377, P=0.016, uncorrected). Conclusions At resting-state, the functional connectivities of the emotional regulation network decreased in drug-naive patients with OCD. Decreased functional connection between left amygdale and right dorsal anterior insula may be associated with anxiety symptoms in patients with OCD. Key words: Obsessive-compulsive disorder; Amygdala; Magnetic resonance imaging; Emotional regulation network