Links between Positive Emotionality and Later Comorbid Symptoms in Toddlers with ASD
Objectives: To examine relationships between directly-assessed and parent-reported positive emotional expression in the second year and symptoms of internalizing and externalizing problems at age 3 in young children with and without ASD.
Methods: Participants included 94 toddlers (Time1: Mage=22mo, range:13-30mo; Time2: Mage=39mo, range:33-47mo), 52 ASD and 42 TD. At Time1, frequency of joy was characterized via parent report (Early Childhood Behavior Questionnaire (ECBQ): Low-Intensity Pleasure subscale (ECBQ_LIP)). Intensity of joyful emotional expression (iEE-Joy) was characterized via direct observation (Laboratory Temperament Assessment Battery (Lab-TAB); Goldsmith & Rothbart, 1999). iEE-Joy across facial and vocal channels was coded during three Lab-TAB episodes designed to elicit joy. At Time2, parents completed the Preschool Anxiety Scale (PAS-R; Total Anxiety score) and the Early Childhood Inventory (ECI-4; Internalizing and Externalizing composites).
Results: In TD children, greater iEE-Joy expressed during the Lab-TAB at Time1 was associated with higher Time2 ECI-4-Internalizing symptoms (r(22)=.665, p<.001) and PAS-R Anxiety (r(27)=.396, p=.041) but not Externalizing symptoms. In the ASD group, iEE-Joy was positively associated with ECI4-Externalizing symptoms (r(30)=.363, p=.049) but not Internalizing or Anxiety symptoms. In the TD children, parent-reported ECBQ-LIP scores at Time1 were negatively associated with ECI-4-Externalizing (r(34)= -.479, p=.002) and PAS-R Anxiety (r(42)= -.360, p=.019) but not Internalizing symptoms. In the ASD group ECBQ-LIP did not significantly predict any later symptoms (ps>.443).
Conclusions: Positive emotionality is a largely neglected area of study in autism research. In toddlers with ASD, directly-assessed intensity of joy was associated with later externalizing symptoms. This finding contrasted with the results for typically-developing toddlers, where, as in previous literature, expression of joy appeared to serve as both a risk and a protective factor: directly-assessed intensity of joy was associated with later internalizing symptoms, while parent-reported frequency of joy during calm activities predicted lower externalizing and anxiety symptoms. Although preliminary, these results suggest that directly-assessed intensity of joy in toddlerhood may be a risk marker for later internalizing and externalizing symptoms in children with and without ASD, while parent-reported frequency of joy during low-key situations may serve as a protective factor against development of externalizing and internalizing symptoms such as anxiety only in typically-developing children. Thus, this study suggests that the pathways to affective and behavioral psychopathology are different for children with and without ASD. Finally, the results underscore the value of a multi-method approach to understanding the development of comorbid symptoms in very young children with ASD.