Early Repetitive Behavior Severity As a Risk Factor for Elevated Anxiety in Autism Spectrum Disorder
Objectives: In the current study we aimed to examine the association between repetitive behavior severity at the time of receiving an ASD diagnosis (age 2-5 years) and the presence of elevated anxiety symptoms in middle childhood (age 8-11 years), while accounting for potential confounding factors.
Methods: In a longitudinal inception cohort of children with ASD (n=421), RRB severity at study enrollment (age 2-5 years) was classified as mild, moderate, or severe using the Autism Diagnostic Interview-Revised. Anxiety was measured on the Child Behavior Checklist at age 8-11 years (T-score cut-off >65). Multivariable logistic regression with multiple imputation for missing data was used to examine the association between RRB severity and anxiety symptoms while adjusting for age, sex, adaptive functioning, baseline anxiety on the CBCL, family income, and parenting stress, generating adjusted odds ratios (aORs) and 95% confidence intervals (CIs).
Results: Approximately 58% of children with severe RRB had elevated anxiety by age 11, compared to 41% of those with moderate RRB, and 20% of those with mild RRB. Moderate and severe RRB was associated with increased odds of elevated anxiety in the adjusted model [Moderate aOR: 2.5 (1.2 to 5.3); severe aOR: 3.2 (1.4 to 7.5)].
Conclusions: RRB severity at time of ASD diagnosis is associated with risk for elevated anxiety symptoms in later childhood. This finding increases our understanding of which children with ASD will develop anxiety disorders, and can help to inform prevention, early identification, and treatment.