Examining the effects of genetic, prenatal illicit drug exposure, and postnatal rearing environment on child school age outcomes

Although many studies have explored the impact of prenatal illicit drug exposure (PDE) on child outcomes, non-PDE risks such as genetic influences and rearing environment that are correlated with PDE make it difficult to... [ view full abstract ]

Although many studies have explored the impact of prenatal illicit drug exposure (PDE) on child outcomes, non-PDE risks such as genetic influences and rearing environment that are correlated with PDE make it difficult to distinguish the effects of PDE from other risks on child outcomes. Identifying the longitudinal effects of PDE on child outcomes, while controlling for other risks, helps to clarify the mechanisms underlying PDE and child development.

Using data from the Early Growth and Development Study (N = 561) we examined effects of PDE on child negative reactivity at 18 months and later problem behaviors at 7 years after accounting for child sex, heritable risks, and negative parenting. Heritable risks for externalizing and internalizing problems were created using birth mothers’ (BM) lifetime psychiatric diagnoses, current symptoms, age of onset of substance use initiation and first-degree parents’ lifetime psychiatric diagnoses. BM reported on their own illicit drug use during pregnancy at 5 months postpartum using a life-history calendar method. A composite of child negative reactivity was created using adoptive parents’ reports of child emotional reactivity (CBCL), anger, fear (TBAQ) and fussy/difficult temperament (ICQ) at 18 months. Child problem behaviors were assessed with adoptive parents’ (AP) reports on the CBCL externalizing and internalizing problems at age 7. A composite of negative parenting was created using AP reports of inconsistent discipline, corporal punishment, and overall hostility at child age 4.5 years.

Results indicated that PDE was negatively associated with child negative reactivity at 18 months (ß = -.50, p = .05). Furthermore, heritable risk for internalizing problems, PDE, and child negative reactivity were positively associated with later internalizing and externalizing problems, but only for boys (ß = -4.05, p < .01, and ß = -3.71, p = .06). For children with PDE, higher levels of negative parenting was associated with increases in children’s externalizing problems at age 7 (ß = -49.86, p = .04).