Trajectories of Focused Attention in Infancy Predict ASD and ADHD Symptoms at Age 3 Years.

Background: The tendency to selectively sustain attention for longer durations correlates with better concurrent learning and better cognitive outcomes later in development. Whilst individuals with Autism Spectrum Disorder (ASD) are commonly observed to show high levels of focused attention once engaged, they may struggle with selectively applying this ability across a range of tasks and contexts. Indeed, ASD is highly comorbid with Attentional Deficit Hyperactivity Disorder (ADHD) and autism symptom severity has been found to associate with difficulties with selective maintenance of attention from the third year of life and beyond. Moreover, difficulties with selectively engaging and maintaining attention may underlie the difficulties with joint attention that are characteristic of ASD. It is not yet known however whether attentional difficulties are primary or secondary to the development of ASD and ADHD symptoms.

Objectives:  To observe patterns of change in the tendency to selectively maintain attention across contexts in the first 3 years of life amongst infants at high risk for ASD. To relate these differences to ASD and ADHD symptoms at age 3 in order to better understand the etiology of ASD and ADHD comorbidity.

Methods: Tendencies in behaviour across contexts are most effectively and efficiently measured with parent report, particularly for infants where moment-by-moment fluctuations in state can be extreme. We therefore collected parent report of the tendency to exhibit focused attention using the Infant Behaviour Questionnaire– Revised at 10 and 14 months, the Early Childhood Behavior Questionnaire at 24 months and the Children’s Behavior Questionnaire at 36 months. This data was collected in a sample of 116 infants at high familial risk for ASD, and 27 low-risk controls. Parent report of autism and ADHD symptom severity at 36 months was captured using the Autism Diagnostic Interview and Child Behavior Checklist-Preschool Assessment respectively. Latent Growth Curve Models were used to examine inter- and intra-individual change over time. By the time of presentation this analysis will be extended to a further sample of 100 infants at high familial risk for ASD and 50 low-risk controls.

Results: Infant levels of focused attention are negatively associated with parent-reported symptoms of autism-related social difficulties (standardised β = -0.638, p<0.05) and ADHD symptoms (standardised β = -1.059, p<0.001) at age 3. Within the same model, growth in focused attention is also associated with parent-reported autism-related social difficulties (standardised β = -3.634, p<0.001) and ADHD symptoms (standardised β = -3.844 p<0.001), and parent-reported symptoms of ASD and ADHD are positively correlated (standardised β = 6.960 p<0.001).

Conclusions: High ASD and ADHD symptoms at age 3 are associated both with low infant levels of focused attention and with slow growth in focused attention. These data highlight the need for longitudinal models when investigating cognitive mechanisms implicated in developmental disorders and lend support to the theory that control of attention is implicated in the etiology of both ASD and ADHD. Further work is underway to validate these findings against observational measures of focused attention and ASD and ADHD symptoms.