A Longitudinal Investigation of Parent Reported Social Functioning in Autism Spectrum Disorders: Still Lots of Room for Improvement

Background:  The current diagnostic framework for autism spectrum disorders (ASDs) emphasizes social impairments, but also notes impaired executive function (EF). There is some evidence for the interdependence of EF and social cognition in the development of early social skills, but little is known about how social functioning (SF) and EF contribute to social outcomes in ASD without intellectual disability.

Objectives: This longitudinal study investigates the trajectory of parent-reported SF in ASD and explores the impact of baseline SF and EF on that trajectory. Specifically, this study investigates whether parent-reported EF and SF at baseline predicts changes in SF over time. We predicted that SF would improve over time in this group of high functioning children with access to clinical services; and that EF at Time-1 would correlate positively with improvement in SF over time. 

Methods: Participants were 38 children, adolescents, and young adults diagnosed with ASD (M FSIQ=107.25) who had two or more clinical or research evaluations (M age Time-1=13.80 ±3.70; M age Time-2=16.96 ±4.23) occurring at least six months apart (M=3.21 years). SF and EF were assessed through parent report on the Behavior Rating Inventory of Executive Function (BRIEF, Global Executive Composite (GEC) T-score) and the Social Responsiveness Scale (SRS, Total T-score). Reliable change indexes (RCIs) were calculated for each participant to determine whether change in SF from Time-1 to Time-2 was clinically significant at the 95^th confidence interval. Lastly, correlation coefficients controlling for age were conducted to assess the relationship between total SF and EF at Time-1 and the change in SF between Time-1 and Time-2.

Results: RCI calculations indicated that 28 participants did not improve in SF (no change N=24; deteriorated N=4) and 10 participants significantly improved between Time-1 and Time-2. There was a significant negative relationship between SF change scores and SF scores at Time-1 (r(33)=-.646, p<001). Analyses also revealed a significant positive correlation between BRIEF GEC scores and total SF scores at Time-1 (r(33)=.395, p=.019), but not between GEC scores at Time-1 and SF change scores. 

Conclusions: These data indicate that only 26% of children with ASD improved in parent-reported SF over time, and that those who improved began with significantly more impaired SF than those who did not improve. Perhaps those most impaired individuals at Time-1 received more intensive interventions, a question to be addressed in future research. Alternatively these data may represent the effect of statistical regression to the mean, in that only those who began with especially elevated social impairment improved over time. This overall lack of improvement in social abilities may have ultimately affected the study’s power to view the true relationship between EF and SF, as EF did not impact the SF trajectory as expected. EF did, however, relate to SF at Time-1, suggesting the need for further exploration of the relationship between these key developmental domains. Overall, this study illustrates a lack of improvement in SF, even in those with access to good clinical care, underscoring the need for the continued development of evidence-based interventions.