Early Life Stress Predicts Decreased Total Brain Volume, Cortical Thickness, and Cognitive Functioning in School-Age Children

Abstract

Severe early life stress (ELS) (e.g., maltreatment/institutionalization) is associated with atypical neurological and cognitive development. Few studies have prospectively examined the neurological mechanisms underlying the cognitive deficits associated with less severe and more common forms of ELS. The current study examined the impact of common forms of ELS assessed during early childhood on children’s brain volume, cortical thickness, and memory and executive functioning assessed three years later in school age children, controlling for current stress. Participants included 63 children (50.8% female) assessed during preschool (Wave 1 age: M=4.23 years, SD=.84) and three years later (Wave 2 age: M=7.19 years, SD=.89). ELS included low socioeconomic status, single parent household, low parental education, child exposure to parental depression, and child exposure to high parental hostility. Children’s current life stress, cognitive abilities, and brain structure were assessed at Wave 2. ELS predicted reduced total gray volume, cortex volume, right inferior parietal thickness, and right superior parietal thickness, controlling for covariates and current stress. ELS also predicted poorer memory and attention shifting, controlling for current stress. Right superior parietal thickness mediated the effects of ELS on story recall memory. Results highlight the possible consequences of less severe forms of ELS on brain volume and cognitive functioning, suggesting potential neural mechanisms to further explore. Early childhood may be a particularly important time for intervention efforts to mitigate the neural and cognitive risks associated with early stress exposure.