Age of Autism Spectrum Disorder Diagnosis and Comorbidity in Children and Adolescents with Autism Spectrum Disorder.

Research is required to study the relationship between age of autism spectrum disorder (ASD) diagnosis and the presence of comorbidities. The Gastrointestinal Symptom Inventory, Autism Spectrum Disorder-Comorbid for Children, Behavior Problem Inventory-Short Form and Social Communication Questionnaire were completed by parents of 129 children and adolescents with a diagnosis of ASD. Results revealed significant relationships between the age of ASD diagnosis, the presence of comorbidities and intellectual disability. Significant correlations were found between the age of ASD diagnosis and self-injurious and stereotyped behavior. Comorbid psychopathology significantly predicted the presence of GI symptoms. In addition, the relationship between comorbid psychopathology and challenging behavior in this study was reported as bi-directional as both comorbidities predicted one another in the sample. Future research needs to consider the role of comorbidities in relation to ASD diagnosis.