Executive Function and Its Relation to Outcomes in Middle Adulthood

Background:  Executive function (EF) is defined as one’s ability to manage oneself and one’s resources including planning, monitoring, and cognitive flexibility (Welsh & Pennington, 1988). The literature documents EF deficits for those with ASD throughout childhood and adolescence (Kenworthy et al., 2008), but little is known about how EF manifests in middle adulthood and its relations to adult outcomes. This is of critical importance because over 50,000 individuals with ASD turn 18 each year suggesting the need to better understand predictors of adult outcomes.

Objectives: The current study investigated EF abilities and its relation to outcomes in adults diagnosed with ASD as children between 1970 and 1999 at the UNC TEACCH Autism Program.

Methods: Participants included 50 adults with ASD (age range 27-57; M age=37.2) who completed assessments measuring IQ (Stanford Binet-5; FSIQ range 40-120; M FSIQ=69.7) and confirm autism diagnosis (ADOS-2). Caregivers of adults with ASD completed measures assessing their adult’s EF (BRIEF-Adult Version), quality of life (QOL-Q), adaptive behavior (Vineland-II), internalizing symptoms (ADAMS), and social functioning (SRS-2). Analyses were conducted to examine the relation of EF to areas of adult functioning.

Results: Bivariate correlations were conducted to assess the relationship between EF and nonverbal IQ (NVIQ), as the literature suggests a connection between these domains. When including the whole sample, there was no significant relationship between EF and NVIQ (r=-.06, p=.69). Because our sample had a large range in NVIQ standard scores (range=42-114; M NVIQ=71), we further probed this relationship by dividing the sample into those with NVIQ>70 (N=27) and NVIQ<70 (N=23). For those with NVIQ>70, there was a significant negative correlation between NVIQ and EF, with those with lower NVIQ scores demonstrating poorer EF (r=-.39, p=.05). However, NVIQ was not related to EF for those with NVIQ<70 (r=-.24, p=.28). Indeed, some individuals with low NVIQ were rated as having no problems with EF. Individuals with NVIQ<70 seemed to be driving the lack of relationship of NVIQ to EF in the full sample, suggesting the BRIEF-A may not be valid for adults with intellectual disability (ID). Thus, we examined the relations between EF and measures of adult outcome only for those with NVIQ>70. In this subsample (N=27), EF was significantly negatively related to overall QOL (r=-.57, p=.002), satisfaction with one’s life (r=-.71, p<.001), adaptive behavior (r=-.55, p=.003), depression (r=-.73, p<.001), anxiety (r=-.69, p<.001), and social functioning (r=-.65, p=.001). All relationships indicate those with poorer EF were reported to have more problems in each of these domains.

Conclusions:  These data indicate that the BRIEF-A may not be an appropriate measure of EF for adults with comorbid ASD and ID. For adults with ASD without ID, results suggest that EF is an important factor in adult functioning and those with poorer EF were rated to have poorer outcomes across all areas assessed. Because EF is considered a domain in which interventions can lead to improved EF abilities (Kenworthy & Anthony et al., 2013), these results support the idea that adult EF programs may facilitate improved adult outcomes.