Friday, May 21, 2010: 10:00 AM
Grand Ballroom CD Level 5 (Philadelphia Marriott Downtown)
9:45 AM
Background: Typically, cluster analytic approaches used in identifying autism subgroups primarily group individuals based upon social, cognitive, and language impairments. However, many individuals with higher functioning autism (HFA) have elevated internalizing and externalizing symptoms, contributing to their highly heterogeneous presentation. Yet, few studies have specifically examined how internalizing and externalizing symptoms differentiate children with HFA using cluster analysis and how such subgroups differ in self-regulatory styles and social presentation.
Objectives: The purpose of the current study was (1) to use cluster analytic techniques to identify distinct phenotypes in a large sample of children with HFA based upon parent reports of internalizing and externalizing symptoms and (2) to examine how these distinct phenotypes differed on indices of self-regulation and social adjustment.
Methods: Preliminary analyses are reported on 80 children with HFA (71 males, 9 females) between 8-16 years old. Subscales of parent-report measures of social anxiety (SASC-R) and internalizing and externalizing symptoms (BASC-2-PRS) were entered into a hierarchical cluster analysis using Ward’s method and Euclidean Squared Distance. One-way ANOVAs were conducted comparing the identified clusters on measures of (a) autism symptoms (SCQ, ASSQ, and SRS), (b) parent and child report of general social adjustment (BASC-2-PRS and BASC-2-SRP), (c) parent report of temperament (EATQ), and a Repeated Measures ANOVA was conducted on (d) performance on a modified version of the Eriksen Flanker task measuring inhibitory control. Post-hoc analyses were conducted to assess differences between clusters.
Results: Four clusters were identified: (1) Primary Externalizing, (2) Internalizing/Externalizing, (3) Primary Internalizing, and (4) No Comorbidity. The groups did not differ on age, verbal IQ, or perceptual IQ. Regarding autism symptoms, the No Comorbidity group was the least symptomatic on the ASSQ, F(3,78)= 41.8, p<.01, and the SRS, F(3,78)=3.29, p<.01. The Primary Externalizing group displayed the most repetitive and stereotyped behaviors, as reported on the SCQ, F(3.78)= 3.79, p< .05. In addition, they self-reported the most Social Stress, F(3,69)=3.52, p< .05, and Anxiety, F(3,69)= 3.04, p< .05. The Internalizing/Externalizing group self-reported marginally greater external Locus of Control, F(3,69)=2.55, p=.06; however, they did not differ from the other groups on other self-regulatory or social adjustment factors. The Primary Internalizing group was rated highest on temperamental Effortful Control, F(3,76)=5.07, p< .01. In addition, this group demonstrated the highest level of inhibitory control by significantly slowing down on incompatible versus compatible trials on the Flanker task, t(12)=-2.91, p< .05. The No Comorbidity group were rated as low in temperamental Negative Affect, F(3,76)= 14.17, p<.01 and high in Surgency, F(3,76)= 9.95, p< .01.
Conclusions: The current study identified four distinct autism subgroups based upon internalizing and externalizing symptoms. These results demonstrate that children with any Internalizing and/or Externalizing comorbidity were rated as having higher ASD symptoms. Differing profiles of regulation were noted between the comorbid groups, with the Primary Internalizing group displaying an overcontrolled style whereas those with a Primary Externalizing presentation showed greater rigidity, which may negatively impact their social relationships. These findings have implications for creating interventions that target the distinct regulatory styles of these phenotypically different subgroups.
Objectives: The purpose of the current study was (1) to use cluster analytic techniques to identify distinct phenotypes in a large sample of children with HFA based upon parent reports of internalizing and externalizing symptoms and (2) to examine how these distinct phenotypes differed on indices of self-regulation and social adjustment.
Methods: Preliminary analyses are reported on 80 children with HFA (71 males, 9 females) between 8-16 years old. Subscales of parent-report measures of social anxiety (SASC-R) and internalizing and externalizing symptoms (BASC-2-PRS) were entered into a hierarchical cluster analysis using Ward’s method and Euclidean Squared Distance. One-way ANOVAs were conducted comparing the identified clusters on measures of (a) autism symptoms (SCQ, ASSQ, and SRS), (b) parent and child report of general social adjustment (BASC-2-PRS and BASC-2-SRP), (c) parent report of temperament (EATQ), and a Repeated Measures ANOVA was conducted on (d) performance on a modified version of the Eriksen Flanker task measuring inhibitory control. Post-hoc analyses were conducted to assess differences between clusters.
Results: Four clusters were identified: (1) Primary Externalizing, (2) Internalizing/Externalizing, (3) Primary Internalizing, and (4) No Comorbidity. The groups did not differ on age, verbal IQ, or perceptual IQ. Regarding autism symptoms, the No Comorbidity group was the least symptomatic on the ASSQ, F(3,78)= 41.8, p<.01, and the SRS, F(3,78)=3.29, p<.01. The Primary Externalizing group displayed the most repetitive and stereotyped behaviors, as reported on the SCQ, F(3.78)= 3.79, p< .05. In addition, they self-reported the most Social Stress, F(3,69)=3.52, p< .05, and Anxiety, F(3,69)= 3.04, p< .05. The Internalizing/Externalizing group self-reported marginally greater external Locus of Control, F(3,69)=2.55, p=.06; however, they did not differ from the other groups on other self-regulatory or social adjustment factors. The Primary Internalizing group was rated highest on temperamental Effortful Control, F(3,76)=5.07, p< .01. In addition, this group demonstrated the highest level of inhibitory control by significantly slowing down on incompatible versus compatible trials on the Flanker task, t(12)=-2.91, p< .05. The No Comorbidity group were rated as low in temperamental Negative Affect, F(3,76)= 14.17, p<.01 and high in Surgency, F(3,76)= 9.95, p< .01.
Conclusions: The current study identified four distinct autism subgroups based upon internalizing and externalizing symptoms. These results demonstrate that children with any Internalizing and/or Externalizing comorbidity were rated as having higher ASD symptoms. Differing profiles of regulation were noted between the comorbid groups, with the Primary Internalizing group displaying an overcontrolled style whereas those with a Primary Externalizing presentation showed greater rigidity, which may negatively impact their social relationships. These findings have implications for creating interventions that target the distinct regulatory styles of these phenotypically different subgroups.