Predictors of Comorbid Psychopathology for Toddlers with ASD

Background:  

Children with autism spectrum disorders (ASD) show elevated rates of comorbid mental illness compared to typically developing peers with rates between 10% and 81% (De Bruin et al., 2007; Levy et al., 2010; Matson, Hess & Boisjoili, 2010). Disruptive behavior disorders and anxiety disorders appear to be the most common forms of mental illness for children with ASD (De Bruin et al., 2007).  However, it remains unclear why these disorders are the most prevalent.  Some investigators have posited a relationship between the symptoms of ASD and later psychopathology, with particular attention given to repetitive/stereotyped behaviors as a mechanism to reduce arousal (Hutt & Hutt, 1965; 1970; Turner, 2003 for a review).  Nevertheless, there is inconsistent support for a relationship between autism symptomatology and anxiety (De Bruin et al, 2007; Sukhodolsky et al., 2008) and further research is needed.  

Objectives:  

The objective of the current study is to examine predictors of later psychopathology in children at risk for ASD. The current study will examine ASD symptoms as predictors of psychopathology, with particular attention given to repetitive/stereotyped behaviors.  

Methods:  

Participants for the current study included infant siblings of children with autism diagnosed with ASD or other related deficits (ASD/Concerns; n = 21) and typically developing controls (TD; n =72). There were no significant group differences in gender, family income or mother’s education.  Slightly more than half of the participants were male and most had family incomes at or above $75,000.  Likewise, most mothers had graduated from college. Scores on the Child Behavior Checklist (CBCL; Achenbach & Rescorla, 2001) administered at 36 months of age measured the propensity towards comorbid psychopathology.  Scores on the social communication and repetitive behaviors domains of the Autism Diagnostic Observation Schedule (ADOS: Lord et al., 2000) at ages 18, 24 and 36 months of age were used as predictors of psychopathology. Repetitive play behaviors from an observed free-play task at 18, 24 and 36 months of age were also used as predictors of psychopathology.

Results:  

Preliminary results demonstrate significant group differences in repetitive/stereotyped behaviors on the ADOS at 18, 24, and 36 months of age (p = .055, p=.00, and p=.00, respectively).  Negative binomial regression analyses were used to account for the positive skew and high frequency of zeros in the CBCL data.  Results support significant group differences in attention problems (p=.065), with ASD toddlers demonstrating more difficulties with attention than TD children.  Results also suggest a relationship between sleep problems on the CBCL and repetitive behaviors on the ADOS at 36 months of age (p=.073), although this relationship is independent of group membership.  

Conclusions:  

Children with ASD demonstrate a greater propensity towards psychopathology than typically developing children and they may have elevated problems with attention.  This is notable given the deficits in attention associated with ASD and the possibility of shared genetic influences with ADHD (Reiersen & Todd, 2008; Ronald et al., 2008).   Furthermore, there may be a relationship between symptoms of autism and sleep problems, although this link appears to be independent of ASD outcome.