Temperament Profiles of Infants Subsequently Diagnosed with ASD

Background: Parent reports of child temperament differentiate children with an Autism Spectrum Disorder (ages 3-8) from typically developing children. Children with ASD tend to be less adaptable, less persistent, and less responsive than typical children (Hepburn and Stone, 2006). In a longitudinal study of infants at risk of developing ASD, those who developed ASD were rated by their parents as more passive than low-risk controls at 6 months, and were more persistent/less distractible in their visual attention to objects at 12 months (Zwaigenbaum, Bryson, Rogers, Roberts, et al., 2005).

Objectives: To examine the temperament profiles of infants who are subsequently diagnosed with autism and to compare these profiles with those of typical children and high-risk children who do not meet criteria for ASD.

Methods: Infants with an older sibling with ASD (n=132) were compared to children with no family history of autism (n=97) at 12 months of age. A subset of the 12-month sample was also seen at 6 months (high-risk: n=98, low risk: n=86). Temperament ratings of children who met criteria for ASD at 36 months (n=20) were compared with those of unaffected high-risk children and with low-risk controls.  The Carey Temperament Scales (McDevitt & Carey, 1996), a parent-report questionnaire, were administered at both the 6- and 12-month time points. ASD diagnoses were conferred at 36 months based on the ADOS-G (Lord, Risi, Lambrecht, Cook, et al., 2000) and clinicians’ best estimates.

Results: Parent reports regarding child temperament differed between diagnostic groups. 6-month-old infants who were subsequently diagnosed with ASD were rated higher on both the Adaptability and Mood subscales of the Carey Temperament Scales than low-risk controls. These scores indicate slower adaptation to environmental changes and more negative affect, respectively. The same patterns persisted at 12 months.  Furthermore, infants who were subsequently diagnosed with ASD were ranked lower on the Distractibility Subscale at 12 months.  Infants in the affected group were less adaptable, less distractible, and more negative in affect than typical children. Mean scores on the Carey subscales were compared between groups using independent samples t-tests. All p values were less than 0.05.

Conclusions: Temperament profiles differentiate children with autism and neurotypical children by 6 months of age. These temperament patterns may be early analogues of later manifestations of autism. They are likely to have a negative impact on children’s social opportunities. Temperamental profiles may be useful in identifying children at heightened risk for ASD.