Early Life Traumatic Brain Injury Constrains the Benefits of High Socioeconomic Status on White Matter Microstructure and Language

Abstract Objective We examined contributions of socioeconomic status (SES) and Traumatic Brain Injury (TBI) to change in language and white matter microstructure (WMM) during adolescence. Method Data are from 11,876 youth with baseline assessment (T1) and 24-month follow-up (T2) in the Adolescent Brain Cognitive Development study (general community sample). TBI data were from the parent-reported Ohio State TBI Identification Method. Language was measured using the NIH-toolbox picture-vocabulary test. TBI cases, with complete data, were nearest-neighbor propensity score matched with non-TBI cases considering handedness, income, race, age, sex, and diffusion tensor imaging quality (N-analyses = 141). WMM in the uncinate fasciculus (UF) was assessed using fractional anisotropy (FA). Analyses were conducted using nested linear models accounting for dependencies, age, sex, and handedness. Results TBI was not independently associated with language or WMM at T1 (mean age in months (MA) = 118.8) or T2 (MA = 142.8) (all p > 0.05). TBI and SES interacted in association with T1 UF-FA (p = 0.03, CI = -0.05, −0.02). Low SES youth did not differ in T1 UF-FA. Among high SES youth, those without TBI had higher UF-FA (p = 0.04). A 3-way interaction between SES, TBI and change in UF-FA between T1 and T2 in predicting language emerged (p = 0.01, CI = 0.12, 1.06). Youth with moderate-to-high levels of UF change did not differ in language. For youth with low increases in UF, SES and language were positively associated only in youth without TBI (p = 0.0003). Conclusion(s) TBI does not have a direct effect on adolescent WMM or language but interacts with SES and WMM to blunt benefit of SES on language.