Childhood socioeconomic status predicts cognitive outcomes across adulthood following traumatic brain injury

Objective: To examine the association between childhood socioeconomic status (SES) and the level and rate of change in intelligence scores throughout adulthood following traumatic brain injury (TBI). Methods: In this longitudinal study we tested 186 patients with TBI and 54 healthy controls from the Vietnam Head Injury Study. Childhood SES was determined for each participant based on parental educational attainment and occupational prestige. General intelligence was initially assessed pre-injury upon induction into the military, and again 15, 35 and 40+ years post-injury. We examined whether childhood SES, total brain volume loss and lesion laterality can predict post-injury intelligence scores and the rate of change in those scores between study phases. Results: For both participants with and without TBI, childhood SES accounted for a significant portion of the variance in intelligence scores pre-injury and in all three post-injury evaluations, however, it was not associated with the rate of cognitive change. Lastly, childhood SES predicted cognitive outcome among patients with left hemisphere damage better than it did for right hemisphere damage patients. Conclusions: These findings provide the first evidence indicating the persistent effects of childhood SES on intelligence scores later in adulthood following a TBI. Childhood SES should be considered when predicting and assessing cognitive recovery following TBI, even when the injury occurred in adulthood.