Prevalence of Anxiety in Autism Spectrum Disorders

This chapter reviews the current knowledge about the prevalence of and risk factors associated with anxiety disorders in individuals with autism spectrum disorder (ASD). Prevalence rates for a diagnosis of an anxiety disorder are considered only from studies that use clinical diagnostic interviews. We report that anxiety disorders are common in individuals with ASD and overall prevalence rates for anxiety disorders as an aggregate group range between 42% and 79%. The prevalence rates for individual anxiety disorders are variable. Specific phobia, obsessive compulsive disorder, and social anxiety disorder are the most common but the rate and type of anxiety disorders may vary across age and ability level. Challenges in measuring anxiety in ASD and factors that may contribute to variation in overall rates and those for specific disorders are discussed. The objective of summarizing the research literature on anxiety in ASD to date is to set out clear guidelines for the future direction of research and also interpret the findings to highlight the key clinical implications.