19440
Early Social Development in Preschoolers with Autism Spectrum Disorders: A Comparison of DSM-5 Profiles

Thursday, May 14, 2015: 5:30 PM-7:00 PM
Imperial Ballroom (Grand America Hotel)
T. A. Bennett1, P. Szatmari2, E. K. Duku1, S. Georgiades3, S. E. Bryson4, E. J. Fombonne5, I. M. Smith6, P. Mirenda7, J. Volden8, C. Waddell9, L. Zwaigenbaum8, W. Roberts10, T. Vaillancourt11, M. Elsabbagh12, A. Zaidman-Zait13 and A. Thompson1, (1)Offord Centre for Child Studies & McMaster University, Hamilton, ON, Canada, (2)University of Toronto, Toronto, ON, Canada, (3)McMaster University, Hamilton, ON, Canada, (4)Autism Research Centre, Dalhousie/IWK Health Centre, Halifax, NS, Canada, (5)Oregon Health & Science University, Portland, OR, (6)Dalhousie University / IWK Health Centre, Halifax, NS, Canada, (7)University of British Columbia, Vancouver, BC, Canada, (8)University of Alberta, Edmonton, AB, Canada, (9)Faculty of Health Sciences, Simon Fraser University, Vancouver, BC, Canada, (10)Pediatrics, University of Toronto, Toronto, ON, Canada, (11)University of Ottawa, Ottawa, ON, Canada, (12)Department of Psychiatry, McGill University, Montreal, QC, Canada, (13)Tel-Aviv University, Tel-Aviv, Israel
Background:  The new diagnostic criteria for autism spectrum disorders (ASD) in the 5th edition of the Diagnostic and Statistical Manual (DSM-5; American Psychiatric Association, 2013) represent an attempt to capture the heterogeneity of symptoms and impairment among children with ASD in a dimensional manner. In DSM-5, associated clinical specifiers describe co-morbid developmental challenges experienced by children with ASD, including structural language impairment (LI) and intellectual disability (ID). Children with ASD plus LI (ASD/LI) and ASD plus ID (ASD/ID) may be at greater risk of adverse social-developmental outcomes than those with ASD alone (ASD/alone). 

Objectives:  We aimed to compare the trajectories of social competence in young children recently diagnosed with ASD/alone, ASD/LI and ASD/ID. 

Methods:  Data were provided by 332 children and their families participating in the Canadian Pathways in ASD study, a multi-site longitudinal inception cohort study of children aged 2-4 years with a recent DSM-IV diagnosis of ASD (278 boys, 54 girls). Children who scored below 70 standard score (SS) points on the Merrill-Palmer-Revised Developmental Index (MPR-DI) were described as ASD/ID (n=249, 75.0% of sample). Among those with baseline MPR-DI scores above 70 SS points, children who scored 1.5 standard deviations below population mean scores on the Preschool Language Scale-4 (PLS-4; Auditory Comprehension or Expressive Communication subscales) were classified as language impaired (ASD/LI; n=32, 9.64%). Children in the ASD/alone subgroup (n=51, 15.36%) scored in the unimpaired range on language and cognitive testing. Participants were assessed at baseline (within 4 months of diagnosis) and 6 and 12 months later. We examined latent growth curve trajectories of early social competence (as measured by the Vineland Adaptive Behavior Scales-II [VABS-II Socialization domain]), and compared parameters of growth (intercept and slopes) of social competence trajectories between the ASD/alone, ASD/LI and ASD/ID subgroups. 

Results:  Twelve months after diagnosis, 74% of children in the ASD/LI group no longer met criteria for language impairment; however, by contrast 69% of the ASD/ID group continued to score as impaired on cognitive testing. On average, children with ASD made significant gains in social competence over 12 months (slope = 7.15 raw points [SE=0.36, p<0.01], equivalent to 3 SS points on VABS-II). There was significant variability within the group with respect to initial levels (intercepts) and rates of change (slopes). Growth parameters were significantly associated with family income (intercept) and child age at diagnosis (intercept and slope), but not child sex or years of primary caregiver education. Children with ASD/LI were significantly more socially impaired at baseline than the ASD/alone subgroup, and less impaired than those with ASD/ID. Rates of change in social competence did not differ between the ASD/alone and ASD/LI subgroups, however children with ASD/ID made significantly fewer social gains during the year after diagnosis. 

Conclusions:  Clinicians should describe DSM-5 diagnoses of ASD/LI as provisional when assessing preschoolers, given the significant language gains made by many children.  The ASD/ID classification appeared to be more stable in the first year after diagnosis. Children with ASD/ID were most severely impaired and lagged further behind in their early social development.

See more of: Early Development (<48 months)
See more of: Early Development (< 48 months)