Age-related differences in the prevalence and correlates of anxiety in youth with autism spectrum disorders

Age-related differences in the prevalence and correlates of anxiety were cross-sectionally examined in 1316 children and adolescents with autism spectrum disorder (ASD) who presented for initial evaluation at 14 outpatient autism centers around the country and in Canada. The prevalence of clinical and subclinical anxiety as well as the correlates of anxiety were examined in three age groups of children: preschool, school age and adolescents. Findings showed that the prevalence of anxiety in each age group exceeded the prevalence of anxiety in the general population. Adolescents and school age children had the highest prevalence of clinical (40%) and subclinical anxiety (26%), respectively. Higher IQ and less ASD severity were each weakly correlated with more anxiety in preschool and school age children. Affective symptoms were strongly associated with anxiety in each age group. Age specific psychiatric comorbidities were also present. Anxiety was associated with attention deficit hyperactivity disorder (ADHD) and oppositional defiant disorder (ODD) symptoms in the preschool group, ODD and somatic symptoms in the school age children, and ADHD symptoms in adolescents. These data underscore the need for prevention and treatment of anxiety as well as research examining the characteristics of anxiety in children with ASD using a developmental framework.