When considered together with our initial study (Mattson et al., 2010b) the data presented herein indicate that approximately 70% of children with heavy prenatal alcohol exposure without FAS are neurobehaviorally affected, even in the absence of FAS. These children would likely be classified as having alcohol-related neurodevelopmental disorder, which falls under the umbrella of FASD (Hoyme et al., 2005, Stratton et al., 1996, Bertrand et al., 2005). Conversely, 30% of this population appears to be spared neuropsychological and behavioral consequences. Examination of the test scores of the misclassified subjects in analysis 2 confirms this suggestion: for all 11 variables as well as IQ, the average score was within the average range. These findings are similar to two other recent studies. In the first, 78% of alcohol-exposed children without ADHD were distinguished from controls using 4 items from the Sluggish Cognitive Tempo Scale (Graham et al., 2011). In the second study, the combination of attention skills and a measure of cognitive effort was used to accurately distinguish alcohol-exposed subjects from controls and from subjects with ADHD with 77% and 73% classification
