Autism spectrum disorders (ASD) are characterized by impairments in reciprocal social skills, abnormal language development, and/or a restricted repertoire of behaviors and interests. Among individuals with ASDs, up to 84 percent are thought to have comorbid anxiety diagnoses, which can result in decreased social, emotional, behavioral, academic, and/or adaptive functioning. While differential diagnosis is necessary in order to create symptom-specific treatment protocols to address anxious symptoms, diagnostic decisions can be difficult for clinicians to make due to the common reliance on self-, parent- and teacher-report measures for collecting data. Based on theory, problems arise because deficits in the individual with ASD\u27s ability to understand and express their feelings, and deficits in the individual with ASD\u27s expressive and receptive language are sometimes thought to hinder their ability to self-report. Also, parent\u27s and teacher\u27s abilities to identify internalizing disorders through observed, externalized symptoms are sometimes questioned. In order to better understand the usefulness of self-, parent-, and teacher-reports for the purpose of improving the accuracy of symptom detection for individuals on the autism spectrum, self-, parent-, and teacher-report data was analyzed. Rrater groups were analyzed, including subjects with and without a comorbid anxiety diagnosis. Results indicated that child, parent, and teacher reports were not correlated. Scores reported by parents and teachers were significantly higher than those reported by children. Differences between raters were not influenced by whether or not the child was given an anxiety diagnosis. For children with ASD ages 6 to 16, age did not have a significant effect on the reporting trends of children, parents, and teachers. Additionally, age did not have a significant effect on scores of children with and without an anxiety diagnosis. When all three rater\u27s scores were factored into the prediction model, parent ratings were the only ratings to significantly improve the model. Parent\u27s scores most often predicted the presence of an Anxiety Disorder, NOS diagnosis, while teachers most often predicted the absence of an Anxiety Disorder, NOS diagnosis
