Autism symptoms in anorexia nervosa: a comparative study with females with autism spectrum disorder.

BACKGROUND: Recent research suggests a link between autism spectrum disorder (ASD) and anorexia nervosa (AN). Individuals with AN show high scores on measures of ASD symptoms, relative to individuals without AN, however, there are currently no studies directly comparing women with AN to women with ASD. The aim of the current study was to examine profiles of ASD symptoms in young women in the acute and recovered stages of AN, women with ASD, and typically developing controls (TD), on both self-report and clinical interview measures. METHODS: Four groups of participants aged 12-30 years were included (n = 218): AN, recovered AN (REC), ASD, and TD. Group differences on the Social Responsiveness Scale, 2nd edition (SRS-2), 10-item Autism Quotient (AQ-10), and the Autism Diagnostic Observation Schedule, 2nd edition (ADOS-2) were examined. To explore similarities and differences in specific symptom profiles associated with AN and ASD, individual item endorsement on the ADOS-2 was also examined in AN, REC, and ASD. RESULTS: Across measures, women with ASD showed the highest scores, and TDs the lowest. Generally, individuals with AN and REC showed intermediate levels of ASD symptoms, scoring between the other two groups. However, AN and ASD did not differ on restricted interests and repetitive behaviour subscales. The ADOS-2 item 'quality of social response' adequately discriminated between ASD and non-ASD participants. LIMITATIONS: A full diagnostic assessment for ASD was not provided for participants with AN/REC, nor were eating disorders assessed in the ASD group. Therefore, some diagnostic overlap between groups is possible. The cross-sectional design is another limitation. CONCLUSIONS: The results suggest similarities in scores on both self-report and clinical interview measures in AN and ASD. However, individual ADOS-2 item analyses also revealed subtle differences, particularly in reciprocal social interaction. ASD symptoms may be a combination of both state and trait features in AN.