The Developmental Trajectory And Dynamic Relationship Between Early Adolescent Sleep Problems And Internalizing And Externalizing Behavior

Sleep,as one of the physiological phenomena that human beings rely on for survival,is closely related to psychology and behavior.Adolescents are in a special stage of puberty,in this period,adequate sleep time and high sleep quality can not only help them eliminate fatigue,improve memory and learning efficiency,more important is to provide a favorable guarantee for the healthy development of the body and psychology.In addition,adolescence is also a time when problem behaviors（internalization and externalization）are prone to occur.Furthermore,in the context of Chinese culture,there are few longitudinal studies specifically focusing on adolescent sleep and problems behaviors,mainly reflected in the following aspects:（1）In terms of research orientation,most of the existing studies used the variable-centered method to explore the relationship between adolescent sleep and other variables,while few studies used the individual-centered approach to explore the individual differences of adolescent sleep;（2）In the research design,most of the existing studies use cross-sectional design,so it is difficult to find the trajectory of sleep development and its potential causal relationship with other variables;（3）In the selection of research participants,few studies have focused on adolescents.From the above consideration,this study chooses adolescents in junior middle school as subjects,combining the perspectives of"individual-centered"and"variable-centered".The longitudinal latent variable causal analysis model was used to explore the sleep and behavior problems development trajectory,influencing factors,longitudinal relationship between variables of interest and the mediation role of emotion regulation.The participants were approached from 29 classes in 4 different middle schools.The present analyses draw on data from the four time points longitudinal survey from2018 to 2020（data assessments Time 1:fall 2018,Time 2:spring 2019,Time 3:fall2019,Time 4:spring 2020）.At the first assessment,participants were seventh graders in their first semester after entering middle school.The overall number of participants was1281 students(M_age=12.73,SD=0.68;range 11-15 years)to explore the development trajectory and related factors of sleep problems and internalizing and externalizing behaviors in adolescents,and to examine the longitudinal relationship between sleep problems and problem behaviors and the mediating effect of emotional regulation.Data were collected with background information questionnaire,adolescent sleep disturbance questionnaire（ASDQ）,the youth self-report（YSR）,and the difficulties in emotion regulation scale（DERS）.All the data were self-reported by adolescents and are analyzed by SPSS 25.0 and Mplus8.3.The data structure is analyzed by latent variable growth curve model（LGCM）,latent variable growth mixed model（LGMM）,cross-lagged panel model（CLPM）,and parallel process latent growth model.The specific results are as follows:Study 1:The developmental trajectory of sleep problems and internalizing and externalizing behavior in adolescents.The results showed that:（1）the sleep problems of adolescents in junior middle school showed a curvilinear trend,which increased at first and then decreased,but the overall trend is increasing.However,during the whole stage of junior high school,the growth trajectory of internalizing and externalizing behaviors are both linear,which indicated that the former decreased gradually and the latter increased at the same time.There were significant individual differences in the initial level and the rate of change of sleep problems and internalizing and externalizing behaviors,and the initial level and changes of each variable would be affected by the general family characteristics.（2）Adolescents’sleep problems and internalized behaviors showed four heterogeneous developmental trajectories,but externalized behaviors showed three heterogeneous developmental trajectories.Study 2:The dynamic relationship between sleep problems and internalizing and externalizing behaviors in adolescents.Data were analyzed using cross-lagged structural equation model.The results indicated that sleep problem significantly predicted later internalizing behavior and vice versa.However,sleep problems significantly predicted later externalizing behavior,not vice versa.Two parallel process latent growth model were used to examine the synchronous relationships between sleep problems and internalizing and externalizing behaviors.There existed significant difference among individuals in the initial level and variation rate,and parallel process latent growth model suggested that the initial level of sleep problems can effectively predicted the initial level of internalizing and externalizing behaviors,and subsequent decreased rate of internalizing behaviors.In addition,the results showed that general characteristic factors have influence on the dynamic change of sleep problem and mental health of adolescents.Study 3:The longitudinal mediating effect of emotion regulation between sleep and problem behavior in adolescents.The results showed that in the mediating effect,the emotion regulation variables showed both specificity and functional coordination.In this study,the exploration of the development trajectory of sleep problems and mental health of adolescents has obtained some valuable research findings,which reflect and verify the dynamics,diversity and plasticity of the sleep and problem behaviors development process of adolescents in junior middle school.The results also found that there was a dynamic effect between sleep and problem behavior in adolescents.Emotion regulation plays an important role in the interaction between sleep and problem behavior.Although it is not a potential factor causing the interaction between sleep and problem behavior,it is the intermediary mechanism of the interaction between sleep and problem behavior.This result reveals the relationship between sleep and psychosocial adaptation in junior high school adolescents and the role of emotion regulation in different angles,the importance of development perspective and background factors in exploring the relationship between sleep and internalizing and externalizing behaviors was emphasized.