A history of social adversity is associated with adolescents' ex vivo inflammatory response

Social adversity is consistently associated with negative mental and physical health outcomes, potentially through dysregulated inflammatory processes. Adolescence is a critical period for these effects to emerge. Traditional baseline measures of chronic inflammation often fail to capture the dynamic nature of inflammatory responses, highlighting the importance of assessing both inflammatory reactivity and sensitivity to inhibition. This study examined whether a history of social adversity predicts adolescents' ex vivo inflammatory responses.

As part of the longitudinal Outside-in study, 333 Belgian adolescents (13.9 ± 0.4 years, 44.1 % girls) provided blood samples via fingerprick in a school setting. Blood was incubated with lipopolysaccharide to assess inflammatory reactivity, and with lipopolysaccharide plus glucocorticoid (GC) to assess GC sensitivity. Cytokine responses were measured for IL-1β, IL-6, and TNF-α. Social adversity, assessed through self-reported bullying victimization and victimization by adults over four waves spanning two years, was used as a predictor. Linear regression models adjusted for sex, pubertal status, and infection-related symptoms, while accounting for multiple testing.

A two-year history of social adversity predicted IL-6 (β=0.119) and TNF-α (β=0.123) reactivity but not GC sensitivity or IL-1β reactivity. Similar patterns were observed for concurrent social adversity and for the two types of adversity analyzed separately.

In this community sample of adolescents, social adversity was associated with heightened inflammatory reactivity of TNF-α and IL-6. This increased reactivity might put adolescents at risk of developing chronic low-grade inflammation over time.