Adaptive Behavioral Dysfunction Is Associated with Increased Risk for ASD Symptoms in Toddlers with Tuberous Sclerosis Complex.
Previous research has suggested that up to 50% of newborns with Tuberous Sclerosis Complex (TSC) will go on to develop autism spectrum disorder (ASD). Given that Tuberous Sclerosis Complex (TSC) can be diagnosed with 95% accuracy via prenatal ultrasonography, TSC offers a unique opportunity to study the early development of ASD. The goal of an ongoing multi-center study is ascertain possible biomarkers that could distinguish infants with TSC who will develop ASD from infants with TSC who do not develop ASD. Potential biomarkers being assessed in this project include imaging, EEG, genetic analysis, assorted clinical measures, and neurodevelopmental assessment measures (including adaptive behavior and behavioral/emotional function). Adaptive behavior deficits have long been associated with suboptimal developmental outcomes. Behavioral problems (e.g., inattention, social withdrawal), can significantly undermine adaptive functioning—which in turn undermines long-term educational, social, and occupational adjustment. At this point, little is known about the relationship between adaptive function and psychopathology in toddlers with TSC—especially with regard to symptoms, such as social withdrawal and emotional reactivity, that are closely associated with ASD.
The goal of this project was to determine if lower adaptive function is associated with higher levels of behavioral and emotional problems—especially symptoms closely associated with ASD-- in toddlers with TSC.
Sample consisted of 66 toddlers (35 boys) participating in the TSC Autism Center of Excellence Research Network (TACERN). Mean age was 24.2 months, mean MSEL Composite was 79.6, and 14 had been diagnosed with ASD) by this point in the study. Adaptive function was assessed using the Vineland Adaptive Behavior Scale (VABS-II). Behavioral/emotional problems were assessed using the Child Behavior Checklist (CBCL, ages 1.5-5 years). Parents served as the informants for both instruments. Correlational analyses assessed the relationship between adaptive function and behavioral/emotional function.
Toddlers with TSC who had lower levels of adaptive function had significantly higher levels of behavioral and emotional concerns. Weaker adaptive function was associated with higher levels of internalizing problems (p<.001) and externalizing problems (p=.04). Of particular note were specific concerns in the areas of, pervasive developmental problems (p<.001), emotional reactivity (p=.022), and social withdrawal (p<.001). Other concerns associate with weak adaptive function included attention problems (p=.005) and affective problems (p=.002). When toddlers with ASD were removed from the sample and correlations re-run, weaker adaptive function was still associated with pervasive developmental problems (p=.001) and social withdrawal (p<.001), suggesting that these findings were not entirely driven by toddlers who had already been diagnosed as having ASD. However, it is possible that ASD had not yet been diagnosed in some of the 24-month old toddlers in this same—an empirical question to be addressed in subsequent neurodevelopmental evaluations.
Even as early as 24 months old, toddlers with TSC who have weak practical living skills are at high risk for behavioral/emotional concerns that are associated with ASD, underscoring the need for early behavioral intervention for these toddlers in order to optimize developmental outcomes.