23056
Adaptive Behavior Impairments Vary with Depression Status in Adolescents and Young Adults with ASD
Adaptive behavior is an important index of functioning in autism spectrum disorder (ASD), and has been shown to predict adult outcomes within this population (Howlin, 2000). ASD is associated with high rates of impairment in adaptive behavior (Rydén & Bejerot, 2008). Despite highly variable symptom expression and intellectual functioning within ASD, existing literature supports a general pattern in the adaptive behavior profiles of adults with ASD, with relative strengths in daily living skills and to a lesser extent communication, and relative weaknesses in socialization (Farley et al., 2009; Kanne et al., 2010).
Other clinical populations, such as adults with depression, tend to experience impaired adaptive functioning as well (Lowe et al., 2008). Empirical evidence suggests high rates of psychiatric comorbidity in ASD across the lifespan, with depression a particularly common co-occurring condition for adults with ASD (Lugnegard et al., 2011). Despite the known negative effects of ASD and depression singularly on adaptive behavior skills, the combined impact is unclear.
Objectives:
This study aims to assess the relation between depression and adaptive behavior in adolescents and adults with ASD. By comparing adaptive behavior profiles of those with and without co-occurring depression, we hope to comment on the effects of depression on adaptive behavior within the ASD population.
Methods:
Participants included 50 adolescents and adults with ASD (16-35 years) and verbal IQ ≥ 70. ASD diagnosis was confirmed via parent completion of the Autism Diagnostic Interview-Revised (ADI-R; Rutter et al., 2003), as well as administration of the Autism Diagnostic Observation Schedule (ADOS; Lord et al., 2000). Parents also completed the second edition of the Vineland Adaptive Behavior Scales (Sparrow et al., 2005) to assess participants’ adaptive functioning in the domains of Daily Living Skills, Communication, and Socialization. Participants completed the Beck Depression Inventory, 2nd edition (BDI-II; Beck et al., 1996) to assess depressive symptoms.
Results:
Verbal IQ was not significantly different between depressed (DEP) and non-depressed (ND) participants. The depressed subsample tended to be slightly older (M=22.5 years, SD=4.3, compared to M=20.2 years, SD=3.8 in the ND group), however group differences were not significant (t(48)=1.67, p=.099). Vineland composite adaptive behavior scores were found to be significantly lower among the depressed sample (M=62.4, SD=12.8 vs. M=74.5, SD=13.1 in ND) when controlling for the effects of age (F(2,46)=3.43, p=.041). Within specific domains, Vineland Daily Living standard scores were significantly lower in the depressed subsample (F(2,47)=5.94, p=.005), as were Communication domain scores (F(2,46)=14.23, p=.000). Vineland Socialization domain scores were not significantly different between groups when controlling for age. BDI-II scores showed a significant negative correlation with both Daily Living (r=-.361, p=.010) and Communication (r=-.410, p=.003) domain scores, but were not significantly correlated with Socialization scores.
Conclusions:
This study provides evidence that comorbid depression exacerbates adaptive functioning impairments in adults with ASD. Furthermore, these data suggest that co-occurring depression is associated with diminished adaptive behavior skills in areas that otherwise tend to be relative strengths within ASD (Daily Living Skills and Communication), providing evidence for unique functional impairments related to this psychiatric comorbidity.