Symptom trajectories in the first 18 months and autism risk in a prospective high‐risk cohort. (29th March 2021)

• Record Type: Journal Article
• Authors: Zwaigenbaum, Lonnie; Brian, Jessica; Smith, Isabel M.; Sacrey, Lori‐Ann R.; Franchini, Martina; Bryson, Susan E.; Vaillancourt, Tracy; Armstrong, Vickie; Duku, Eric; Szatmari, Peter; Roberts, Wendy; Roncadin, Caroline
• Is Part Of: Journal of child psychology and psychiatry and allied disciplines. Volume 62:Number 12(2021)
• Page Start: 1435
• Page End: 1443
• Publication Date: 2021-03-29
• Subjects: Autism spectrum disorder -- early detection -- high‐risk studies -- longitudinal studies; Child psychology -- Periodicals; Child psychiatry -- Periodicals; 155.4
• DOI: 10.1111/jcpp.13417
• Languages: English
• ISSNs: 0021-9630

Abstract

Abstract : Background: Although early autism spectrum disorder (ASD) detection strategies tend to focus on differences at a point in time, behavioral symptom trajectories may also be informative. Methods: Developmental trajectories of early signs of ASD were examined in younger siblings of children diagnosed with ASD ( n = 499) and infants with no family history of ASD ( n = 177). Participants were assessed using the Autism Observation Scale for Infants (AOSI) from 6 to 18 months. Diagnostic outcomes were determined at age 3 years blind to previous assessments. Results: Semiparametric group‐based modeling using AOSI scores identified three distinct trajectories: Group 1 ('Low', n = 435, 64.3%) was characterized by a low level and stable evolution of ASD signs, group 2 ('Intermediate', n = 180, 26.6%) had intermediate and stable levels, and group 3 ('Inclining', n = 61, 9.3%) had higher and progressively elevated levels of ASD signs. Among younger siblings, ASD rates at age 3 varied by trajectory of early signs and were highest in the Inclining group, membership in which was highly specific (94.5%) but poorly sensitive (28.5%) to ASD. Children with ASD assigned to the inclining trajectory had more severe symptoms at age 3, but developmental and adaptive functioning did not differ by trajectory membership. Conclusions: These prospective data emphasize variable early‐onset patterns and the importance of a multipronged approach to early surveillance and screening for ASD.