The Characteristics And Neural Mechanism Of Interception Of Patients With Anxiety Disorder

Backgroud: Interoception is associated with neural activity in the insula.Based on the somatic symptoms(especially abnormal heartbeat perception)in generalized anxiety disorder(GAD)and panic disorder(PD),but it's still unclear about the neural process of interoceptive awareness in patients with GAD and PD.Objective: 1.To investigate the characteristics of interoception of patients with PD and GAD.2.To explore the possible neural mechanism of abnormal interoceptive awareness of patients with anxiety disorder.Methods: We recruited first-onset drug-na?ve patients with GAD(n=34),patients with PD(n=18)and 51 healthy controls(HC,n=51)to investigate the characteristics and its neural activities of interoceptive awareness through behavioral scales and magnetic resonance imaging.Furtherly,we compared BOLD responses respectively between GAD and HC,PD and HC during a heartbeat perception task,including of its relationship to anxiety severity.Additionally,we examined differences in insular subregions resting-state functional connectivity(rs FC)and its relationship to anxiety severity.Moreover,we compared blood oxygen level dependent(BOLD)responses between the two disease groups during a heartbeat perception task,including of its relationship to heartbeat perception scores(HPSs).Results: There were no significant different age and gender distribution among GAD,PD and HC.We found GAD had significantly higher body perception scores than HC.GAD also exhibited elevated task-evoked activity in the left anterior insula,left posterior insult and right anterior insula during interoceptive awareness compared with HC.Left anterior insula activity was positively correlated with body awareness in patients with GAD.Moreover,rs FC between the left anterior insula and left medial prefrontal gyrus was negatively correlated with somatic anxiety severity.HPSs were higher in patients with PD than that in HCs,but the difference didn't reach significant level.There was also increased activity level in the bilateral superior parietal lobule(SPL)of PD patients than of HCs during heartbeats and puretones compared to baseline.Furthermore,patients with PD exhibited significant positive correlation tendency between BOLD activity level in the left SPL and HPS during heartbeat vs resting-state,and a positive correlation between BOLD activity in the right SPL and HPS.Conclusions: We found that there was an increase of bilateral SPL activity level in patients with PD and a positive correlation between HPS and SPL activity.It suggests that PD patients may be processing their internal status information more intensively,which may increase the likelihood of panic attacks.The body perception of GAD patients was significantly increased.The hemodynamic response of the insula was significantly enhanced.The left anterior insula played an important role on mental anxiety.The abnormal functional connections between the left anterior insula and the left prefrontal cortex were negatively correlated with somatic anxiety among patients with GAD.This study suggest that abnormal insular activity and connectivity also play an different important roles in abnormal interoception of patients with anxiety disorder(both GAD and PD).