3.29 INVESTIGATING AUTISM SPECTRUM TRAITS IN ADOLESCENTS WITH ANOREXIA NERVOSA AND AVOIDANT/RESTRICTIVE FOOD INTAKE DISORDER

Objectives: Several studies have reported that patients with AN may have elevated autism spectrum traits. However, there is limited knowledge regarding other ED. Furthermore, no studies have investigated correlations between autism spectrum traits and severity of ED. The purpose of this study was to compare autism spectrum traits between AN, avoidant/ restrictive food intake disorder (ARFID), and typical controls (TC) in adolescents. Methods: AN and patients with ARFID also participated in another research study, Japanese Pediatric Eating Disorders Outcome: a Prospective Multicenter Cohort Study. In the present study, a cross-sectional independent group design was used. There were three groups in the study as follows: 1) adolescents with AN (n =60); 2) adolescents with ARFID (n = 30); and 3) TC (n = 372). All groups were tested using the Autism-Spectrum Quotient Children's Version (child AQ). Furthermore, the children's version of the Eating Attitude Test-26 (ChEAT-26) was investigated. Results: AN and ARFID groups showed significantly higher mean child AQ total scores than the TC group, with a large effect size (P = 0.000, P = 0.004, respectively). Yet, mean child AQ total scores were not significantly different between AN and ARFID groups (P = 0.45). On the subscales, the AN group had higher social skills, attention switching, local details, and communication skills than the TC group. The group with AFRID had higher social skills, attention switching, and local details than the TC group. In addition, there was a correlation between autism spectrum traits (AQ total, social skill, communication skills, and imagination) and severity of ED in male participants with ARFID (n = 6). Conclusions: Adolescents with AN and ARFID showed a greater number of autistic spectrum traits than TC but not significantly different between AN and ARFID groups. Autism spectrum traits, such as obsessive interest that thrive on routine, may maintain food refusal among adolescents with AN and ARFID. To our knowledge, this is the first study to assess autistic spectrum traits in adolescents with ARFID. Further investigation of autistic spectrum traits in ED may improve our understanding of patients.