Research On Superiority Illusion Impairment In Bipolar Depressive Disorder

Bipolar disorder is a chronic recurrent disease affecting 1%of the world population.It has the characteristics of high prevalence,high heritability,high recurrence rate and high comorbidity.Cognitive impairment in bipolar disorder distorts the recognition and processing of social information and seriously affects the normal social life of patients.In addition,negative self-schema is regarded as the core feature of the cognitive model of depression.Bipolar depressive disorder(BDD),as one of the subtypes of the depression,also has the similar negative self-schema.Patiens tend to generate negative self-evaluation and link the negative stimuli to themselves.For most individuals,however,there is a cognitive bias called the "superiority illusion(SI)",which makes people believe that they are superior to the average peers.This illusion plays a decisive role in the evolution of human beings.The underlying neurological mechanisms behind the cognitive impairment of BDD is still unclear,and there is no research have attempted to explore the cogtive impairment from the perspective of SI.In this thesis,using the the self-schema of BDD induced by superiority illusion paradigm,we explore functional activation and structural volume variation of patients under the condition of negative personality traits,and look for possible imaging biomarkers.The research content mainly includes the following two parts:1.Previous researches mainly foucused on the healthy individuals and explored the neural mechanism of SI.It was found that resting-state functional connectivity between the frontal cortex and striatum regulated by inhibitory dopaminergic neurotransmission determined individual levels of the superiority illusion.Based on the seed-based functional connectivity,we explored the resting state functional connectivity between ventral striatum and cerebral cortex in BDD.We found the abnormal functional connectivity between striatum and cognitive control,emotion regulation and visual cortex network.Moreover,the left abnormal caudate associated with right superior ventral striatum was positively correlated with task performance in patients with BDD.In the study,our results further clarified that the important role of the striatum plays an important role in SI defict in patients with BDD.2.Few research have used the superiority illusion paradigm to cognitive impairment in BDD.Hence,we apply superiority illusion paradigm to induce the self-schma in patients with BDD,combined with the multimodal magnetic resonance data of the task and the structural image,using the whole analysis and the functional-structural coupling method to investigate thebrai mechanism of superiority illusion defect in patients with BDD under the c.ondition of negative personality traits.The results showed that the functional activation and gray matter structure volume of the parietal lobe,insula and the orbito-frontal cortex were significantly reduced in patients with the BDD,and the coupling between the functional activity and gray matter structure of these regions also signifi,cantly decreased in the patients.The functional-structural coupling in the left insula was negatively related with Hamilton depression scale(HAMD).These results further explained the underling neuroimaging mechanism in superiority illusion defects in BDD.