Prenatal methamphetamine exposure and inhibitory control among young school-age children.

OBJECTIVE: To examine the association between prenatal methamphetamine exposure and inhibitory control in 66-month-old children followed since birth in the multicenter, longitudinal Infant Development, Environment, and Lifestyle study. STUDY DESIGN: The sample included 137 children with prenatal methamphetamine exposure and 130 comparison children matched for race, birth weight, maternal education, and type of insurance. Inhibitory control, an executive function related to emotional and cognitive control, was assessed using a computerized Stroop-like task developed for young children. Hierarchical linear modeling tested the relationship between the extent of prenatal methamphetamine exposure (heavy, some, or none) and accuracy and reaction time outcomes, adjusting for prenatal exposure to alcohol, tobacco, and marijuana; age; sex; socioeconomic status; caregiver IQ and psychological symptoms; Child Protective Services report of physical or sexual abuse; and site. RESULTS: In adjusted analyses, heavy prenatal methamphetamine exposure was related to reduced accuracy in both the incongruent and mixed conditions on the Stroop-like task. Caregiver psychological symptoms and Child Protective Services report of physical or sexual abuse were associated with reduced accuracy in the incongruent and mixed consitions and in the incongruent conditions, respectively. CONCLUSION: Heavy prenatal methamphetamine exposure, along with caregiver psychological distress and child maltreatment, are related to subtle deficits in inhibitory control during the early school-age years.