ADHD News & Research

Review: Anxiety Disorders More Than Twice as Common in Adults with Autism

Anxiety disorders are diagnosed in more than 20% of adults with autism spectrum disorder (ASD), compared to just 8.7% of neurotypical adults, according to a new study out of Stockholm.

March 30, 2020

Anxiety disorders are diagnosed in 20.1% of adults with autism spectrum disorder (ASD) compared with 8.7% of controls, with the greatest prevalence for anxiety among autistic adults without an intellectual disability, according to a recent study published in the Journal of Autism and Developmental Disorders1. What’s more, anxiety disorders are more common in full and half-siblings of individuals with ASD — a finding from a sibling analysis that opens the door to more research regarding a genetic correlation between autism and anxiety.

Researchers used data from the Stockholm Youth Cohort to identify 221,694 individuals ages 18 to 27 — 4,049 of whom had been diagnosed with ASD. They found that just over one-fifth of adults with ASD had been diagnosed with an anxiety disorder; the same was true for only 8.7% of adults without ASD. The prevalence of anxiety disorder was highest among adults with autism who did not have a comorbid intellectual disability.

In addition, the prevalence of obsessive compulsive disorder (OCD) was significantly higher in individuals with ASD (3.43%) compared with the general population (0.47%), and the prevalence of phobic anxiety disorder was also markedly higher. The risk for an anxiety disorder diagnosis for adults with ASD without an intellectual disability (ID) was almost three times higher than that for the general population (adjusted RR 2.96 [95% CI 2.77–3.16]), and higher than the same estimate for adults with ASD and ID (adjusted RR 1.71 [95% CI 1.47–1.99]).

The full- and half-siblings of individuals with ASD also face an elevated risk of anxiety disorder, compared with the general population, according to a complementary study. The risk for anxiety among siblings did not appear to vary with the presence or absence of an intellectual disability in the family member with ASD.

These findings show that anxiety disorders are a significant issue for adults with ASD and that there is a need for effective, evidence-based treatments, especially given the growing volume of research supporting the use of cognitive behavioral therapy (CBT) to treat anxiety in children with ASD.

Since this was a register based study, researchers were unable to verify the anxiety disorder diagnosis, which is notable since there are phenomenological differences in presentation of anxiety disorders in individuals with ASD and/or intellectual disabilities. Further research is warranted.

View Article Sources

1Nimmo-Smith, Victoria, et al. Anxiety Disorders in Adults with Autism Spectrum Disorder: A Population-Based Study. Journal of Autism and Developmental Disorders (Jan. 2020)