Comorbid symptoms in toddlers diagnosed with autism spectrum disorder with the DSM-IV-TR and the DSM-5 criteria

Autism spectrum disorder (ASD) is correlated with a high probability of comorbid psychopathology. Comorbid symptoms are often equally impairing and deserving of intervention. With publication of the DSM-5, it is likely that many children who would have met the previous DSM-IV-TR criteria for ASD will not be diagnosed under the current criteria. The aim of this study is to examine common comorbid symptom categories (i.e., tantrum/conduct, inattention/impulsivity, avoidance, anxiety/repetitive behavior, and eating/sleep problems) of children who exhibit significant ASD symptoms but do not meet DSM-5 criteria. The study included toddlers who meet DSM-5 criteria for ASD; 320 who meet DSM-IV-TR criteria only, and a comparison group of 1951 atypically developing toddlers referred for evaluation but who did not meet either set of ASD criteria. Unsurprisingly, toddlers meeting the more stringent DSM-5 ASD criteria also exhibited greater comorbid symptoms, especially anxiety/repetitive behavior. Those who met only DSM-IV-TR criteria exhibited more comorbid symptoms than the atypically developing group in all categories, most notably inattention/impulsivity and tantrum/conduct. As the new DSM-5 criteria are adopted, researchers and clinicians should consider those who do not meet criteria for ASD may still have symptoms warranting assessment or intervention.