Abstract
BACKGROUND: Heavy prenatal alcohol exposure and attention-deficit/hyperactivity disorder (ADHD) are associated with adaptive behavior deficits. This study examined the interaction between these 2 factors on parent ratings of adaptive behavior. METHODS: As part of a multisite study, primary caregivers of 317 children (8 to 16 years, M = 12.38) completed the Vineland Adaptive Behavior Scales-Second Edition (VABS-II). Four groups of subjects were included: children with prenatal alcohol exposure with ADHD (AE+, n = 82), children with prenatal alcohol exposure without ADHD (AE-, n = 34), children with ADHD (ADHD, n = 71), and control children (CON, n = 130). VABS-II domain scores (Communication, Daily Living Skills, Socialization) were examined using separate 2 (Alcohol Exposure [AE]) × 2 (ADHD diagnosis) between-subjects analyses of covariance. RESULTS: There were significant main effects of AE (p < 0.001) and ADHD (p < 0.001) on all VABS-II domains; alcohol-exposed children had lower scores than children without prenatal alcohol exposure and children with ADHD had lower scores than those without ADHD. There was a significant AE × ADHD interaction effect for Communication, F(1, 308) = 7.49, p = 0.007, partial η(2) = 0.024, but not Daily Living Skills or Socialization domains (ps > 0.27). Follow-up analyses in the Communication domain indicated the effects of ADHD were stronger in comparison subjects (ADHD vs. CON) than exposed subjects (AE+ vs. AE-), and the effects of alcohol exposure were stronger in subjects without ADHD (AE- vs. CON) than in subjects with ADHD (AE+ vs. ADHD) CONCLUSION: As found previously, both prenatal alcohol exposure and ADHD increase adaptive behavior deficits in all domains. However, these 2 factors interact to cause the greatest impairment in children with both prenatal alcohol exposure and ADHD for communication abilities. These results further demonstrate the deleterious effects of prenatal alcohol exposure and broaden our understanding of how ADHD exacerbates behavioral outcomes in this population.