A prospective case series of high-risk infants who developed autism
Susan E Bryson1, Lonnie Zwaigenbaum, Jessica Brian
1Autism Research Centre, IWK Health Centre, Dalhousie University, 5850 University Avenue, Halifax, NS, Canada, B3K 6R8. susan.bryson@iwk.nshealth.ca
Insights
This study tracked nine high-risk infants, finding two subgroups: one with declining IQ and earlier autism signs, and another with stable IQ. All showed social-communicative and sensory-motor challenges.
Area of Science:
- Developmental psychology
- Neuroscience
- Pediatrics
Background:
- Prospective follow-up of high-risk infants from 6 months of age to document autism/autistic spectrum disorder development.
- Investigating early developmental trajectories in infants with elevated risk for autism spectrum disorder.
Observation:
- Nine high-risk infants were observed, revealing two distinct developmental subgroups.
- Subgroup 1 (n=6) exhibited a significant IQ decline from average to severe cognitive impairment between 12-36 months.
- Subgroup 2 (n=3) maintained average or near-average IQs throughout the observation period.
Findings:
- Autism signs emerged earlier and were more pronounced in the subgroup with cognitive decline.
- All nine infants presented with early social-communicative impairments.
- Atypical sensory and/or motor behaviors, irritability, distress, and dysregulated state were common across all participants.
Implications:
- Highlights distinct developmental pathways in high-risk infants, suggesting different underlying mechanisms for autism spectrum disorder.
- Emphasizes the importance of early identification of social-communicative and sensory-motor deficits.
- Suggests potential for targeted early interventions based on identified subgroups and behavioral profiles.
Abstract:
The present paper documents the development of autism/autistic spectrum disorder in a consecutive series of nine high-risk infants followed prospectively from 6 months of age. Evidence is provided for two broadly defined subgroups: the first subgroup (n = 6) showed a decrease in IQ between 12 and 24 or 36 months (from average/near average to severe cognitive impairment), whereas the second subgroup (n = 3) continued to obtain average or near average IQs. Signs of autism emerged and/or were more striking earlier in the first subgroup. In all nine children, early impairment in social-communicative development coexisted with atypical sensory and/or motor behaviors, as did a temperamental profile marked by irritability/distress and dysregulated state. Discussion focuses on issues raised by the pattern of findings.
