Study Of Factors Influencing The Developmental Trajectory Of Depressive Symptoms In Adolescents And Differences In Gut Microbiota Composition

ObjectivesThe developmental trajectory of depressive symptoms is heterogeneous,identifying groups with similar trajectories as well as their influencing factors may provide new insights into the development of depressive symptoms in secondary school students,and be helpful to establish targeted interventions and prevent students from depression based on high-risk factors to improve the effectiveness.MethodsThe study population was recruited from a natural cohort established by our research group in a junior middle school in Huaibei City,Anhui Province.All seventh grade freshmen were included in the cohort in September 2019.The prevalence of depressive symptoms among the included students was investigated using a questionnaire containing the Center for Epidemiological Studies Depression Scale(CES-DC),with annual follow-up in autumn thereafter until graduation,1,814 students included in the initial survey,eventually,obtained 1687 students three times depressive symptom scores.Using the Traj plugin installed in Stata v.16.0 and applying groupbased trajectory model(GBTM)to explore the trajectories of depressive symptoms and influencing factors among secondary school students.ResultsFour trajectory groups of depressive symptoms were identified in the sample of secondary school students included in the cohort.These were the low-stable group(60.8%),the increasing group(23.1%),the decreasing group(8.5%)and the high-stable group(7.6%).In particular,compared with the low-stable group,female,poor relationship with parents,poor relationship with friends,poor family economic status,and childhood abuse were predictors of secondary school students being classified into the low-increasing and high-stable groups of depressive symptoms(OR > 1,All P <0.01).ConclusionThis study identified four trajectory groups for the development of depressive symptoms in the secondary school student population.Identifying secondary school students at high risk of depression and risk factors will be beneficial for preventing students developing depression.The targeted interventions to improve secondary school students’ social relationships and to provide support for secondary school students who have experienced childhood abuse may be effective in preventing the development of depressive symptoms in secondary school students to a certain extent and maximizing the effectiveness of the interventions.Objectives The present study compared the composition of gut microbiota in secondary school students with different depressive trajectories(Low stable vs.High stable)to further understand the role of gut microbiota in the development of depression in secondary school students.Methods A total of 108 secondary school students were included in this study,of which 54 secondary school students belonged to the high-stable depressive symptoms trajectory group(M/F: 27/27)and 54 secondary school students belonged to the low-stable depressive symptoms trajectory group(M/F: 27/27)as controls,and all secondary school students were from the natural cohort in Huaibei City,Anhui Province.The gut microbiota of the faecal samples were sequenced by the Illumina platform for the 16 S r RNA gene V3-V4 region of the bacteria.The sequenced data were denoised to obtain a characterization table of the gut microbiota for subsequent analysis,including sequencing depth analysis,species composition analysis,α-diversity analysis,β-diversity analysis,partial least squares discriminant analysis,t-test volcano plot analysis,LEfse analysis and functional prediction analysis.Results The sparse curve responded that the current sequencing depth was able to detect the vast majority of the gut microbiota contained in each sample and could be used for subsequent analysis.PLS-DA analysis showed that Lachnospira was the main contributor to the differentiation between the two subgroups.Gammaproteobacteria were more abundant and Clostridia were less abundant in the gut microbiota of students along the high-stable depressive trajectory compared to students along the low-stable depressive trajectory.In the level 2 KEGG pathway,functional prediction analysis revealed significant differences(Adjusted P < 0.05)in a total of four KEGG pathways between the two groups of secondary school students.These were immune system function,digestive system function,amino acid metabolism function and lipid metabolism function,respectively.Conclusions This study found significant changes in the gut microbiota of secondary school students from the high-stable depressive symptoms trajectory compared to those from the low-stable depressive symptoms trajectory,with a significant increase in the relative abundance of pathogenic microorganisms and a significant decrease in the relative abundance of microorganisms that maintain normal digestive function.Also,the changes in immune system function,digestive system function,amino acid metabolism and lipid metabolism were found between the two trajectory groups.Future studies could establish a natural cohort of depression development to further understand the bacterial changes in the key functions of the gut microbiota during the development of depression,and on the other hand,experimental studies based on maintaining or improving the normal function of the gut microbiota could be attempted to gain more insight into the effects of interventions on the reduction and even the treatment of depression.