Assessment of Psychiatric Comorbidity in ASD: Investigation of the Recently Developed "Autism Comorbidity Interview" and Issues of Self-report

Background: Clinicians view psychiatric comorbidity in ASD as the rule. However, comorbid disorders in ASD are poorly understood, partly due to measurement problems. Assessment measures have varied across studies, and typically involve questionnaires or measures not validated for use in ASD. Objectives: Explore a new interview for assessing psychiatric comorbidity in ASD and establish the utility of self-report.

Methods: Participants will include forty adolescents (mean age = 12; range 10-17) with ASD (verified by the ADOS and ADI) and IQs over 70. Probands and parents are interviewed with the Autism Comorbidity Interview (ACI) regarding the proband’s mental health. Participants complete a variety of commonly used self-report questionnaires (e.g. Child Depression Inventory, Reynolds Child Manifest Anxiety Scale).

Results: Preliminary analyses from 20 participants indicate that 26% and 31% of the sample met criteria for DSM-IV depressive and anxiety disorders respectively based on the ACI; these rates were 52% for both when subsyndromal and subthreshold diagnoses were included. Many symptoms were inapplicable to the child with ASD via the ACI’s additional queries. For example, 67% of parents reported that their child cannot recognize when others are annoyed, which makes the “purposefully annoys others” symptom of oppositional defiant disorder inapplicable. Chi-square tests indicated lack of agreement between parent-based ACI diagnoses and self-report on both the ACI and screening questionnaires.

Conclusions: Many children with ASD suffer from psychiatric comorbidity that causes additional impairment. The ACI shows promise for differentiation of psychiatric disorders in ASD. Its strengths include consideration of baseline functioning and applicability to the child with ASD. Determining applicability is necessary to avoid misdiagnoses and accurately reflect the underlying causes for problem behavior. Weaknesses of the ACI are the long administration time and extensive examiner expertise needed. Extreme caution should be used when assessing for comorbid disorders via both interview- and questionnaire-based self-report.