Comorbid Psychopathology in Autism Spectrum Disorder

Comorbidity, the co-occurrence of two or more disorders in the same person, has been a topic receiving considerable attention in the child psychopathology literature overall. Despite many publications in the ADHD, depression and other child literatures, autism spectrum disorder has not received such scrutiny. The purpose of this review will be to discuss the available evidence. We address specific variables in diagnosis and classification of comorbid symptoms, and propose potential avenues for research and practice with respect to differential diagnosis. A brief discussion of the implications for treatment is also provided.

Recent studies have shown that rates of depression and anxiety symptoms are elevated among individuals with autism spectrum disorders (ASDs) of various ages and IQs and that depression/anxiety symptoms are associated with higher IQ and fewer ASD symptoms. In this study which examined correlates of depression and anxiety symptoms in the full school-age range of children and adolescents (age 6-18) with ASDs and IQs ≥ 70 (n=95), we also observed elevated rates of depression/anxiety symptoms, but we did not find higher IQ or fewer ASD symptoms among individuals with ASDs and depression or anxiety symptoms. These findings indicate an increased risk for depression/anxiety symptoms in children and adolescents with ASDs without intellectual disability, regardless of age, IQ, or ASD symptoms.