Language Profiles of Individuals with a History of ASD Who Have Optimal Outcomes

Background: A study is currently following children who have a history of autism spectrum disorder (ASD), but who no longer meet diagnostic criteria for such a disorder. These children have achieved social and language skills within the average range for their ages and receive little or no school support. Several recent studies suggest that this small subset of children, once diagnosed with ASDs, achieve "optimal outcomes" (OO; Sutera et al., 2007; Helt et al., 2008; Kelley, Naigles, & Fein, 2010). Kelley, Naigles, & Fein (2010) found that their OO group showed some small, but notable differences in language scores compared to a typically developing group.

Objectives: The current study examines language skills as measured on the Clinical Evaluation of Language Fundamentals, 4^th Edition (CELF-IV), California Verbal Learning Test (CVLT), Comprehensive Test of Phonological Processing Nonword Repetition subtest (CTOPP NR), and Test of Language Competence (TLC) in a cohort of OO individuals. The study compares these language abilities in the OO group to abilities in a group of individuals with high-functioning autism (HFA) and a group of typically developing (TD) individuals.

Methods: Participants included 32 OO individuals, 34 HFA individuals, and 30 TD individuals. Participants were matched on sex, age (M(OO) = 12.75, SD = 3.30; M(HFA) = 13.28, SD = 2.67; M(TD) = 13.80, SD =2.63), and performance IQ (M(OO) = 112.81, SD = 14.41; M(HFA) = 110.45, SD = 14.03; M(TD) = 113.43, SD = 11.45). Verbal IQ scores, although all within the average range, differed significantly across the groups (M(OO) = 112.66, SD = 13.83; M(HFA) = 102.85, SD = 12.29; M(TD) = 111.77, SD = 10.57, p < .01).  We compared the three groups’ performance on four tests of language ability.

Results: We performed ANOVAs to assess group differences in overall performance on language testing. On the CELF-IV Core Language composite, the OO, TD, and HFA groups scored significantly differently from each other (M(TD) = 118.00, SD = 6.73,  M(OO) = 109.70, SD = 10.97, M(HFA) = 97.58, SD = 16.59, p<.05), though well within the average range. On both the CVLT and CTOPP NR, there were no significant differences across groups.  Lastly, on the TLC, a measure of pragmatic language abilities, there were significant differences between the HFA and both the OO and TD groups on the Making Inferences subtest (HFA<OO, TD p<.01).  On the TLC Figurative Language subtest, there were significant differences between all three groups (HFA<OO<TD, p<.01).

Conclusions: Data were collected from a group of OO individuals who no longer meet criteria for ASD on the ADOS. They also scored within the average range on all language measures. However, despite their generally strong language skills, these OO individuals scored significantly worse than TD peers on measures requiring them to interpret figurative language.  Thus, given their high IQs, these OO individuals appear to be exhibiting relative weaknesses compared to TD peers in some language skills. However, they are doing well overall, as their scores consistently fell within the average range across language domains.