Early Temperament As a Predictor of Psychopathology in Younger Siblings of Children with Autism

Background:  

According to the National Survey of Children's Health (McPheeters et al., 2011), 5.6% of children with autism spectrum disorder (ASD) have a comorbid psychiatric disorder before the age of 6 years, whereas a striking 48% of children with ASD over the age of 6 years have an additional psychiatric disorder.  These data underscore the urgent need for research designed to identify and treat early precursors of psychopathology in children with ASD before the onset of comorbid psychiatric disorders.  Younger siblings “at risk” for ASD provide an ideal sample in which to examine early risk factors of emergent psychopathology.

Objectives:  

To explore the potential relationship between early temperamental profiles of younger siblings of children with autism and the onset of psychopathology during the early school years.

Methods:  

Participants included 74 younger siblings with 36-month outcome diagnoses of ASD (Sibs-ASD; n=21) and no ASD (Sibs-No ASD; n=53) enrolled in a prospective study of child development by age 14 months.  Data were collected at two time points.  At time 1 (T1; age 30-40 months (mean age = 36; SD = 1.2), parents completed the Behavioral Style Questionnaire (BSQ; McDevitt & Carey, 1996).  The BSQ yields standard scores for: Activity; Rythmicity; Approach; Adaptability; Intensity; Mood, Persistence; and Threshold of Response.  At time 2 (T2; age 4 to 8 years; mean age = 5.9, SD = 1.3), parents completed the Behavior Assessment Scale for Children, second edition (BASC-2; Reynolds & Kamphaus, 2004). Multiple regression analyses were conducted for Sibs-ASD and Sibs-No ASD separately, using BSQ standard scores at T1 as predictor variables and BASC-2 standard scores on the Externalizing Behavior and Internalizing Behavior Composite scales at T2 as dependent variables. 

Results:  

Independent samples t-tests revealed that, at T1, Sibs-ASD scored significantly higher (more impaired) in Adaptability than Sibs-No ASD (t=4.85, p=.0001), and Sibs-No ASD scored significantly higher in distractibility (more distractible) than the Sibs-ASD group (t=5.54, p=.0001). 

 Results of the regression analyses for Sibs-ASD showed that Persistence at T1 predicted Externalizing Behaviors at T2, accounting for 28% of the variance [F(1,20)=7.029, p=.016].  There were no significant predictors of Internalizing Behaviors for the Sibs-ASD group.  

 For Sibs-NoASD, Activity and Distractibility at T1 predicted Externalizing Behaviors at T2, accounting for 46% of the variance [F(1,53)=20.916, p=.0001].  Mood at T1 predicted Internalizing Behaviors at T2 in Sibs-NoASD, but accounted for only 13% of the variance [F(1,53)=7.301, p=.009]. 

Conclusions:  

Findings suggest that developmental psychopathology in children with and without ASD is likely to have different ontogenies.  In Sibs-ASD, lack of persistence when faced with difficult tasks was predictive of externalizing symptoms, possibly indicating low tolerance for frustration and poor self-regulatory control.  For Sibs-No ASD, elevated levels of activity and distractibility were predictive of T2 externalizing problems.  Further research is needed to determine how characteristics of externalizing problems in children with and without ASD differ, and the efficacy of preventative interventions targeting the developmental predictors of these problems.