The Effects Of 5-HTTLPR Gene,BDNF Gene And Maternal Rearing Behavior On Early Adolescents' Depression

Depression is one of the most common and important emotional disorders and psychological problems that affect individual development.It has an important genetic basis.According to the symptoms and severity of depression,it can be divided into three categories as depression mood,depressive syndromes and major depression(which is always called depressive disorder).Depression increases the risk of smoking,substance abuse and obesity,and even lead to suicide.Cross sectional studies and longitudinal studies have shown a dramatic increase in the incidence of depression in early adolescence.Around 5% of adolescents worldwide are suffering from depression.Adolescents suffer from depression which may lead to psychological and behavioral problems such as dropout,poor interpersonal relationship,anxiety,substance abuse,early pregnancy and suicide.In addition,there is a close relationship between adolescents' depression and mental health,social function in adult.The etiology of depression is of great significance for early detection and early intervention of depression.With the rapid development of molecular genetics,it is possible to determine the specific genes related to depression.A growing number of researchers are devoting to the study of the genetic mechanism of depression and the interaction between genes and environmental concerns.However,the genetic mechanism of depression is much more complex than that of Huntington's disease and other genetic disorders such as phenylketonuria.Therefore,it is a key way to explore the interaction between multiple genes and environmental factors on depression.Thus,basing on the investigation of specific candidate genes for depression of early adolescents,in order to reveal the mechanism of depression,we use the traditional method as regression analysis and recent popular methods as regions of significance(RoS)and re–parameterized regression to investigate the effect of genes(5–HTTLPR and BDNF Val66Met)and maternal rearing behavior on early adolescents' depression.The main conclusions were as follows:(1)The direct effect of polygenic scores of 5-HTTLPR gene and BDNF gene on early adolescents' depression was significant.Specifically,the higher the scores(the more the risk genes)were,the higher the level of depression of adolescents;the lower the scores(the less the risk genes)were,the lower the level of depression of adolescents.(2)Maternal positive rearing behavior significantly and negatively predicted early adolescents' depression,and maternal negative rearing behavior had significant positive predictive effect.(3)The interaction between the polygenic scores and the positive maternal rearing behavior was significant on depression of early adolescents,and the gene–environment interaction model was consistent with weak diathesis–stress models.When the level of maternal rearing behavior is low,but higher level of early adolescent depression,and subjects who carried more risk alleles(3,4)showed higher level of depression than subjects who carried less risk allele(0~2).And when the level of positive maternal rearing behavior was high,the prediction was not significant.