More than intelligence: distinct cognitive/behavioral clusters linked to adaptive dysfunction in children.

Impairments in adaptive functioning are frequently associated with intellectual disability (ID); however, adaptive dysfunction can be seen in many individuals with a variety of neurological conditions without ID. The extent to which other variables may be associated with adaptive dysfunction is unclear. In a mixed clinical sample of children (n = 348) consecutively referred for neuropsychological evaluation, the majority were rated as showing weak adaptive skills (ABAS-II, >1 SD below the mean; 71%), with a substantial proportion evidencing frank impairment (>2 SD below the mean, 45%). We examined patterns of scores on measures of intelligence (WISC-IV) and behavioral/affective dysregulation (BRIEF and BASC-2). Using hierarchical cluster analysis, a four cluster model yielded the most appropriate fit and adaptive functioning was subsequently examined across clusters. As expected, adaptive functioning was most intact in the cluster characterized by average IQ and minimal behavioral dysregulation. Other clusters were marked by adaptive dysfunction and distinguished by sub-average intellectual functioning and varying behavioral/emotional dysregulation. In contrast to traditional views associating low IQ with adaptive dysfunction, adaptive impairment was comparable between the cluster characterized by low intelligence and the cluster with average intelligence but significant behavioral dysregulation. These data suggest that adaptive functioning should be considered across various cognitive/behavioral conditions.