Objectives: The aim of this study is to examine the risk and protective factors associated with anxiety and depression in a representative sample of Irish adolescents.Methods: Data used in this study were drawn from a subset of the My World Survey (MWS). The MWS-Second Level (MWS-SL) subset consists of a randomised sample of 72 schools, with a final sample of 6085 students. Outcome measures were depression and anxiety. Risk and protective factors included measures within the socio-demographic, psychosocial and risk-taking domains.Results: One in three adolescents experienced elevated levels of depression and anxiety. Age, gender, maternal education, family composition, parental mental health as well as the experience of racism and bereavement were associated with elevated distress. Psychosocial factors associated with depression and anxiety included optimism, personal competence, life-satisfaction, self-esteem, anger, body dissatisfaction, family competence, maternal and paternal criticism, experiencing the break-up of a romantic relationship, school and peer connectedness as well as the availability of one good adult. Finally, engaging in substance misuse was found to increase the likelihood of anxiety and depression.Conclusion: Since factors protecting and putting adolescents at risk of anxiety and depression exist at every level of the adolescent’s ecological system, the study supports a community-based approach to youth mental health.

Background: There is substantial evidence that many depressed individuals experience impaired executive functioning. Understanding the causes of executive dysfunction in depression is clinically important because cognitive impairment is a substantial contributor to functional impairment. This study investigated whether elevated levels of an inflammatory cytokine [interleukin-6 (IL-6)] and/or higher body mass index (BMI) concurrently and/or prospectively accounted for the relationship between depressive symptoms and impaired executive functioning in adolescents.Methods: A diverse, community sample of adolescents (N = 288; mean age = 16.33; 51.4% female; 59.0% African-American) completed assessments of height and weight, IL-6, depressive symptoms, and self-report/behavioral measures of executive functioning (selective attention, switching attention) and future orientation annually over 3 years. Adolescents experiencing acute illness or medical conditions that affect inflammation were excluded from analyses. Path analysis within a structural equation modeling framework simultaneously examined the concurrent and prospective relationships between BMI, IL-6, depressive symptoms, and the measures of cognitive functioning across three timepoints.Results: Across all timepoints, higher BMI was prospectively associated with higher levels of IL-6 and depressive symptoms, while higher levels of IL-6 were associated with worse performance on three behavioral and self-report measures of cognitive functioning. Higher depressive symptoms also were prospectively associated with elevated IL-6 and both higher depressive symptoms and a higher BMI predicted worse future executive functioning via increased IL-6.Conclusions: More severe depressive symptoms and increased BMI may disrupt executive functioning via elevated IL-6.

Inflammation has been implicated in depressive symptoms, but few studies use longitudinal designs with adolescents. Furthermore, the extant literature has yielded inconsistent results. Blood was collected from a community sample of 201 adolescents (109 female, age range = 12.3–20.0 years) and analyzed for inflammatory proteins. Up to five follow-up assessments of depressive symptoms were conducted. Multilevel modeling indicated that high C-reactive protein (CRP) but no other proinflammatory markers predicted depressive symptom increases. Three-way interactions between different inflammatory biomarkers, sex, and months to follow-up predicted change in depressive symptoms. Higher interleukin-6 predicted increased depressive symptoms at 13 to 31 months after baseline assessment of depression and inflammation for females. Higher tumor necrosis factor-α predicted increased depressive symptoms at < 1 month after baseline for males and 13 to 31 months after baseline for females. Higher interleukin-8 in males predicted lower depressive symptoms at 31 months after baseline. Exploratory post hoc analyses were used to examine these predictive associations for specific subsets of depressive symptoms. These findings are the first to support the predictive association of elevated CRP for depressive symptoms in a community adolescent sample and serve as preliminary evidence that the relationship between cytokines and later depressive symptoms differs by sex, time to follow-up, and the specific biomarker.