The Longitudinal Effects of Early Adversity on BMI, Inflammation, and Depressive Symptoms: Results from a Nationally Representative Sample of the United States

Objective: Childhood maltreatment is a major risk factor depressive symptoms in adulthood. Current theories suggest that an upregulation of inflammatory signaling may help explain this association, as well as the many overlapping medical comorbidities that share an inflammatory pathophysiology. However, current evidence is hampered by a lack of nationally representative longitudinal studies that utilize repeated measures designs. Further studies frequently include early socioeconomic conditions and body mass index as control variables despite theoretical relevance as key pathways. Thus, the present study aimed to create a model exploring these pathways using nationally representative data and a repeated measures design to identify novel treatment mechanisms for depressive symptoms.

Method: Data are from The National Longitudinal Study of Adolescent to Adult Health (Add Health), an ongoing nationally representative panel study with five available waves of data. First, a cross lagged panel model tested the associations between depressive symptoms measured by the Center for Epidemiologic Studies Depression Scale at Waves 3-5, C-reactive protein (CRP) as an index of overall inflammatory signaling at Waves 4 and 5, and BMI at Waves 3-5. The effects of early life adversity on depressive symptoms, CRP, and BMI were then explored via the inclusion of five childhood maltreatment variables (occurrence of emotional abuse, physical abuse, sexual abuse, social neglect, and physical neglect) and two socioeconomic variables at Wave 1 (family socioeconomic disadvantage and neighborhood socioeconomic disadvantage). Last, the model was adjusted for sociodemographics and covariates known to influence the association between CRP and depressive symptoms. The model was estimated using robust maximum likelihood estimation and accounted for the complex survey design of the Add Health study.

Results: The sample had a mean age of 39 and identified primarily as non-Hispanic White (67%) and female (76%). Model fit indices were mixed after adjusting for confounding covariates and sociodemographic variables. Early family socioeconomic disadvantage was associated with an increased risk for emotional abuse (β=-0.053, p<0.05), physical abuse (β=-0.089, p<0.001), social neglect (β=-0.078, p<0.01), and physical neglect (β=-0.056, p<0.05). Neighborhood socioeconomic disadvantage was associated with an increased risk for physical neglect (β=0.054, p<0.05). Exploring the longitudinal effects of early adversity: emotional abuse (β=0.056, p<0.05), sexual abuse (β=0.073,p<0.01), social neglect (β=0.064, p<0.01), and family socioeconomic disadvantage (β=-0.071, p<0.01) were associated with increased Wave 3 depressive symptoms. Family socioeconomic disadvantage (β=-0.150, p<0.001) and neighborhood socioeconomic disadvantage (β=0.122, p<0.001) were associated with increased Wave 3 BMI. There was no association between early adversity variables and Wave 4 CRP. Exploring cross-lagged effects: Wave 3 depressive symptoms were positively associated with Wave 4 BMI (β=0.036, p<0.05). Cross sectional associations were noted between BMI and CRP at Wave 4 (β=0.188, p<0.001) and BMI and CRP at Wave 5 (β=0.240, p<0.001).

Conclusion: Reducing BMI via early treatment of depressive symptoms may be critical for attenuating the overlapping health related sequalae of childhood maltreatment and depression that have an inflammatory component. Further, results point towards a need for interventions that reduce socioeconomic disparities experienced by families, thereby reducing the risk for childhood maltreatment while improving mental and physical health.