EXAMINING PREDICTORS OF CHILDHOOD MENTAL HEALTH ACROSS THE BRAIN, BODY, AND BEHAVIOR

Most psychiatric disorders first emerge in childhood or adolescence, and it is increasingly recognized that many disorders have developmental antecedents even before the escalation to a clinically impairing disorder. Despite this, there is often a delay of multiple years between disorder onset and initiation of effective treatment, and prevention efforts are even more limited. Thus, there is a need to identify mental health risk earlier in life. The studies presented in this dissertation aim to characterize correlates and predictors of childhood emotional and behavioral problems across the brain, body, and behavior. Study One leveraged a naturalistic, movie-watching functional MRI task to examine how 4–10-year-old children’s neural processing of socioemotional stimuli related to their mental health outcomes. During movie events that captured positive affect and parent-child interactions, activity in neural regions related to reward processing was related to children’s concurrent symptoms of anxiety/depression and aggression. In Study Two, I explored the developmental correlates of accelerated development, as measured by molar eruption timing. 4-7-year-old children exposed to early adversity had earlier eruption of their first permanent molars. In turn, children with earlier molar eruption had more externalizing symptoms, and lower performance on assessments of fluid reasoning, working memory, and crystallized knowledge. These findings suggest that knowing the pace of a child’s maturation may provide insight into the impact of their stress history on their emotional and cognitive development. Finally, Study Three investigated behavioral sensitivity to psychosocial influences at age 3 years and mental health in middle childhood. I used novel repeated-measures design to calculate the sensitivity of 3-year-olds’ behavior to multiple psychosocial influences: parent praise, parent stress, child mood, and child sleep. Children who were more sensitive to their parents’ praise and to their own mood had fewer internalizing and externalizing problems when they were 5-7-years old. Taken together, these studies highlight three potential avenues of identifying young children with the greatest vulnerability for psychopathology. This work contributes to an overarching goal of identifying psychiatric risk earlier in life, in order to direct prevention and intervention services to families who need them most, and ultimately alter lifelong trajectories of mental illness.