Inflammatory pathways of depression in adolescents – Identifying Depression Early in Adolescence (IDEA) study

Abstract

While the role of inflammation in adult depression is well documented, less is known in the context of adolescent depression. Our study aims to identify inflammatory markers associated with increased risk and presence of adolescent depression We recruited 150 adolescents stratified into 3 groups based on the depression risk score previously developed by our team: 1) low risk of developing depression, 2) high risk of developing depression, 3) current depression. Each group included 25 girls and 25 boys. We measured serum cytokines (IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, IL-13, TNF-α, and IFN-γ) using multiplex assay. Depression diagnosis was assessed by a structured clinical interview and dimensional depression with a self-report scale. We found a significant interaction between gender and the risk group on IL-2 levels. In boys, IL-2 increased from low risk to high risk reaching the highest levels in the depressed group (F=5.47, p<.01). Higher IL-2 in boys (rs=.38, p<.01), and IL-6 in girls (rs=.29, p=.01) were associated with more severe depressive symptoms. Our findings suggest a gender specific role of inflammatory pathways in the development of adolescent depression.