| Research background and purpose:Adolescent patients have become the main population of depression sufferers in our country.Currently,the causes of depression remain unclear,and exploring the risk factors,mechanisms,and intervention strategies for adolescent depression holds practical significance.Childhood trauma experiences have long been considered one of the high-risk factors leading to adolescent depression,but the internal mechanisms between childhood trauma and depression are still not well understood.Beck’s cognitive model of depression suggests that negative events occurring in early life contribute to the formation of negative schemas.When these schemas are reactivated,they influence cognitive processes and ultimately lead to the emergence of depressive symptoms.In terms of cognition,individuals with depression exhibit features such as a bias towards processing mood-congruent information and impaired cognitive control mechanisms.Firstly,they tend to avoid positive stimuli during information processing and exhibit a bias towards negative stimuli in perception,attention,and memory processes.Such cognitive processes are closely related to the depressive mood,rumination,and anhedonia.Secondly,individuals with depression experience difficulties in cognitive control over negative stimuli and struggle to regulate their processing of negative materials through their own efforts.In the realm of memory processes,compared to healthy individuals,individuals with depression have difficulty actively forgetting negative stimuli.This leads to individuals with depression being immersed in negative memories for extended periods,which hinders the recovery of their condition.However,current research on active forgetting in depression mainly focuses on exploring differences in this ability between individuals with depression and healthy individuals,as well as analyzing the underlying neural mechanisms.There is limited research investigating the role of directed forgetting ability and cognitive bias in individuals with depression regarding childhood trauma and its relationship with depression.Based on Beck’s cognitive model of depression,this study analyzes the relationship between attention bias towards negative events,directed forgetting,childhood trauma,and depression from the perspectives of mood-congruent processing bias and cognitive control processes.This not only enriches the theoretical understanding of the model but also provides new insights into the etiological analysis and therapeutic interventions for depressed adolescents from a cognitive perspective.Materials and Methods:Recruiting a total of 198 depressed adolescents and 42 healthy adolescents,the study employed the item-method directed forgetting paradigm.Participants were instructed to process 120 images,comprising positive,neutral,and negative images,selected from the "Chinese Affective Picture System." After each image presentation,a memory instruction of either "to be remembered"(TBR)or "to be forgotten"(TBF)was given.Participants were required to remember the content associated with the "TBR"instruction while intentionally attempting to forget the content associated with the"TBF" instruction.A mixed experimental design of 2(group:depressed adolescents,healthy adolescents)× 3(valence of materials:positive,neutral,negative)× 2(instruction condition:TBR,TBF)was used to compare the differences in correct recognition rates of the different condition pictures between depressed and healthy adolescents.Additionally,the Childhood Trauma Questionnaire-Short Form(CTQ-SF),Attention to Negative Information questionnaire(ANI),and Beck Depression Inventory-Ⅱ(BDI-Ⅱ)were administered to measure the severity of childhood trauma experiences,attention bias toward negative events,and current depressive symptoms in depressed adolescents,respectively.The study aimed to analyze the mechanisms underlying the interaction between attention bias toward negative events,directed forgetting ability,childhood trauma experiences,and depression in depressed adolescents.Result:Depressed adolescents had lower correct recognition rates for pictures associated with the "TBR" instruction compared to healthy adolescents,while their correct recognition rates for pictures associated with the "TBF" instruction were higher than the healthy group(Ps<0.001).Compared to healthy adolescents,depressed adolescents had faster reaction times(P=0.005)and higher correct recognition rates(P=0.027)for negative pictures.Conversely,they had slower reaction times(P=0.014)for positive pictures,but the difference in correct recognition rates was not statistically significant(P>0.05).Healthy adolescents had significantly higher correct recognition rates for positive and neutral pictures associated with the "TBR" instruction compared to depressed adolescents(Ps<0.009),whereas they had significantly lower correct recognition rates for neutral and negative pictures associated with the "TBF" instruction compared to depressed adolescents(Ps<0.001).Healthy adolescents showed marginally faster reaction times for positive and neutral pictures associated with the"TBR" instruction compared to depressed adolescents(Ps<0.010),while depressed adolescents had significantly faster reaction times for negative pictures associated with the "TBF" instruction compared to healthy adolescents(P=0.016),and they also showed marginally faster reaction times for negative pictures associated with the "TBR"instruction compared to healthy adolescents(P=0.069).Among the positive,neutral,and negative emotional pictures,healthy adolescents had significantly higher correct recognition rates for pictures associated with the "TBR" instruction compared to those associated with the "TBF" instruction(Ps<0.05),while depressed adolescents only exhibited similar differences between the two memory instructions for positive pictures(P<0.001).CTQ-SF scores in depressed adolescents significantly positively predicted ANI scores(β=0.441).ANI scores significantly positively predicted BDI-Ⅱ scores(β=0.178).CTQ-SF scores in depressed adolescents also significantly negatively predicted negative memory directed forgetting effect(DF effect)(β=-0.151).Negative memory DF effect significantly negatively predicted BDI-Ⅱ scores(β=-0.233).Additionally,ANI scores significantly negatively predicted negative memory DF effect(β=-0.354).ANI scores in depressed adolescents partially mediated the relationship between CTQ-SF scores and BDI-Ⅱ scores(effect size=0.079,accounting for 16.5%of the total effect).The directed forgetting effect of negative memory in depressed adolescents partially mediated the relationship between CTQ-SF scores and BDI-Ⅱ scores(effect size=0.035,accounting for 7.4%of the total effect).ANI scores in depressed adolescents and the directed forgetting effect of negative memory jointly mediated the relationship between CTQ-SF scores and BDI-Ⅱ scores(effect size=0.036,accounting for 7.6%of the total effect).Conclusion:Depressed adolescents have a bias towards negative information processing and avoidance of positive information in the process of memory;Compared with healthy individuals,it is difficult for depressed adolescents to forget neutral and negative information irrelevant to the current task through the cognitive control mechanism;while their directed forgetting ability for positive information is relatively intact;Childhood traumatic experience is a high-risk factor for adolescent depression.The severity of childhood traumatic experiences of depressed adolescents can directly affect the current degree of depression,and can also affect the degree of depression by affecting their attention bias to negative events and the ability to forget negative memories.Negative attention bias and directed forgetting ability of negative memory play a chain mediating role between childhood trauma experience and depression in depressed adolescents.Childhood traumatic experience aggravates the attention bias of depressed adolescents to negative events,and the attention bias makes it difficult for them to forget negative memories,which ultimately affects depression. |
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