The Interpretation Bias And The Relationship With Self-relevance In Depression

Object and SignificanceDepression is a severe mental disorder with high incidence,high recurrence rate,high suicide rate,bringing a huge economic burden for the human society.At present,more than 350 million people suffer from depression all over the world.Because of social stigma of mental illness and the lack of physicians resources,only less than 50% of the patients get effective treatment.Depression as a global health crisis,more attention has been paid to its pathogenesis and the treatment.Previous studies discussed cognitive bias(attentional bias?memory bias?interpretation bias and cognitive control deficits)was a key factor and core characteristic in depression,which can contribute to the onset and maintenance of depressive symptoms.Now researches on cognitive bias focus on attention and memory,the results confirmed that the depressed individuals had the attentional bias and memory bias to the negative stimulus in varying degrees,leading to the occurrence and development of the depression.But these can't explain the pathogenic mechanism of depression entirely.And the negative interpretation bias can enhance the negative memory bias or support negative self-belief to affect the incidence of depression,which means the effect of interpretation bias is equally important in depression.However,until now only few researches have been done to examine interpretation bias of depression,especially the research under the Oriental culture about Chinese with self-relevance has not been reported.Besides there are some shortcomings on previous research methods and the selection of subjects,this field deserves further exploring.Our research based on self perspective of Chinese under oriental collectivism culture,adopting the depressive individuals as experimental subjects,Word Sentence Association Paradigm(WSAP)and Ambiguous Scenarios Test(AST)were used to investigate how the depression interpret the ambiguous information at On-line and Off-line stage,and the relationship between interpretation processing and self-relevance;Meanwhile,we use Word Sentence Association Paradigm(WSAP)and ERPs(Event-Related Potentials)to explore the behavioral characteristics and nerve electrophysiology mechanism of interpretation processing with self-relevance in clinical depression,in order to perfect the theories and Neurophysiological evidences of interpretation bias.Subject and Methods: Adopting the Beck Depression Inventory-?to screen the depressive group subjects(n=20)and the control group subjects(n=21),Word Sentence Association Paradigm(WSAP)and Ambiguous Scenarios Test(AST)were used to investigate On-line and Off-line interpretation processing respectively in ambiguous scenarios with different self-relevance types(self-relevance/intimate relationship/unrelated others).Recruiting clinical unipolar depression(n=15)and the control group subjects(n=16),cognitive behavior experiment(Word Sentence Association Paradigm,WSAP)and ERPs(Event-Related Potentials)experiment were used to explore the behavioral characteristics of interpretation processing and the neural electrophysiological activities under self-relevant conditions.Behavior experiment data were processed with SPSS18.0 and ERPs data were processed by Curry7 software.Results1.On-line interpretation processing of the depressive individuals under three different self-relevance types:In general,there were significant differences between the depressive group and the control group of endorsement rate and reaction time on benign words and negative words(P<0.001).Compared with the control group,the depressive group's endorsement rate on negative words was higher,and the endorsement rate on benign words was lower;There were significant differences within three self-relevance types in depressive group of the endorsement rate on negative words(P<0.001),the endorsement rate on negative words was highest under unrelated others condition,and it was lowest under intimate relationship condition.Compared with the control group,the depressive group's reaction time of benign words and negative words were both longer;There were significant differences within three different self-relevance types in depressive group of the reaction time on benign words(P<0.001),the reaction time on benign words was longest in self-relevant condition,and it was shortest in unrelated condition.2.Off-line interpretation processing of the depressive individuals under three different self-relevance types:In general,there were significant differences between the depressive group and the control group of probability scores on negative interpretation?neutral interpretation and positive interpretation(P<0.001).Compared with the control group,the depressive group's probability scores were higher on negative interpretation,and lower on neutral interpretation and positive interpretation.Under three self-relevance types,there were significant differences between two groups of probability scores on negative interpretation ? neutral interpretation and positive interpretation(P < 0.05);In any conditions,the depressive group's probability scores were always higher on negative interpretation,and lower on neutral interpretation and positive interpretation.Besides that,the depressive group's probability scores of negative interpretation were highest in self-relevant condition,and lowest in unrelated condition.3.On-line interpretation processing of the clinical depression under self-relevance condition: There were significant differences between the depression group and the control group of endorsement rate on benign words and negative words(P<0.001);Compared with the control group,the depression group's endorsement rate on negative words was higher,and the endorsement rate on benign words was lower.As to the reaction time,There were significant differences between the depression group and the control group on reaction time to endorse/reject the benign words(P<0.05),the control group was faster to endorse /reject the benign words than the depression group;there were significant differences between two groups on reaction time to reject the negative words(P<0.001),the control group was faster to reject the negative words than the depression group.4.The ERP data of On-line interpretation processing of the clinical depression under self-relevance condition: To present different values of emotion words,the control group had bigger N1 amplitude for benign words and negative words,and the depression group had bigger LPP(350-550ms)amplitude for negative words.When to respond to negative words,Compared with the control group rejecting the negative words,the depression group was induced a bigger N2 amplitude by endorsing the negative words.To respond to benign words,the control group was induced a bigger N1?N2 amplitude by endorsing the benign words;and the depression group was induced a bigger LPP(350-550ms)by rejecting the benign words.Conclusion:1.The research of On-line interpretation processing in depressive individuals revealed a negative interpretation bias and a lack of a benign interpretation bias.Meanwhile,the negative interpretation bias existed in both self-relevance condition and non-self-relevance condition.2.The research of Off-line interpretation processing in depressive individuals also revealed a negative interpretation bias and a lack of a benign interpretation bias.Meanwhile,the negative interpretation bias existed in both self-relevance condition and non-self-relevance condition.Besides,compared with On-line interpretation processing stage,bias characteristics at Off-line stage was more stable,self-schema would be further activated.3.The research of On-line interpretation processing in clinical depression revealed a negative interpretation bias and a lack of a benign interpretation bias.ERPs data showed that the depression surely had a negative bias in interpretation processing,and in later period of controlled processing,the bias was more stable and significant.