They noted, however, that there may be "subtle residual deficits" among the OO participants that the assessments did not detect, and they are analyzing further results of cognitive ability, language, academics, and executive function testing for later reporting.
Dr. Fein and her associates also noted that analyzing peer interaction and the quality of friendships would more conclusively establish evidence of normal social functioning in the OO group.
The surprisingly higher average IQ scores among the OO individuals also points to the possibility that "above average cognition allowed individuals with ASD to compensate for some of their deficits" or that there was a higher study volunteerism rate among families with higher-IQ children, they said. Further, OO participants were screened to specifically include scores in "the normal range on specific cognitive and adaptive measures," reducing likely differences between the OO and TD children.
The study’s applicability also has significant limitations. The researchers cannot address the question of how many children with ASD can necessarily reach these outcomes, which would require a prospective, longitudinal study. The study also does not offer insights into which interventions – if any – might more likely produce an optimal outcome, which itself was narrowly defined in this study. It’s also unclear whether the optimal outcomes result from compensatory functioning or from actual changes in brain structure and function, Dr. Fein and her associates said.
The researchers also mentioned a lack of diversity in their study, which enrolled mainly children in the northeastern United States and largely white participants. They theorized that OO may be rare in children from minority groups or families with lower socioeconomic status because of lack of optimal interventions or resources.
Other "crucial questions" remain related to the "biology of remediable autism, the course of improvement, and the necessary and sufficient conditions, including treatment, for such improvement," they said.
The study was funded by the National Institutes of Health. The authors said that they had no relevant disclosures.