Investigating the relationship between orthorexia nervosa and autistic traits in a university population.

BACKGROUND: Orthorexia nervosa (ON) is an emerging condition featuring restrictive eating behaviors on the basis of subjective beliefs about food healthiness. Many authors have stressed the similarities between ON and anorexia nervosa (AN) in both cognitive and behavioral patterns. Despite that, while the link between AN and female autism presentations is well known in the literature, no study has yet investigated the relationship between ON and autism spectrum. This work aims to investigate the relationship between ON and autistic traits in a university population. METHODS: An e-mail invitation was sent to all the students and University workers of University of Pisa. Subjects were asked to fulfill the ORTO-15 and the Adult Autism Subthreshold spectrum (AdAS spectrum) questionnaires. RESULTS: A total of 2426 subjects joined the survey: 623 subjects (26.3%) reported a score associated with significant orthorexic symptoms according to ORTO-15 (ON group), while 1789 subjects (73.7%) did not report ON symptomatology and were considered as healthy controls (HC). The ON group scored significantly higher on almost all AdAS spectrum domains. Moreover, being female and scoring higher on AdAS spectrum were statistically predictive factors for the presence of ON symptomatology. Among AdAS spectrum domains, higher scores on AdAS spectrum inflexibility and adherence to routine and restricted interests and rumination domains, as well as lower scores on verbal communication domain, were statistically predictive of orthorexic symptoms. CONCLUSIONS: Our findings highlight an overlap between ON and autism spectrum psychopathology. Further studies are needed to clarify the relationship between restrictive eating disorders and female autism phenotypes.

Defining the Optimal Threshold Scores for Adult Autism Subthreshold Spectrum (AdAS Spectrum) in Clinical and General Population.

BACKGROUND: The Adult Autism Subthreshold Spectrum (AdAS Spectrum) is a recently developed instrument tailored to assess the broad range of full-threshold as well as sub-threshold manifestations related to the autism spectrum. Although it has proved to be a valuable instrument for quantitative assessment of autistic symptoms, the AdAS Spectrum still lacks validated diagnostic thresholds. OBJECTIVE: The aim of this study was to define the best cut-off scores of the AdAS Spectrum for determining the presence of subthreshold autistic traits as well as a clinically significant autism spectrum disorder (ASD). METHODS: Our sample was composed of 39 patients with full-blown ASD, 73 subjects with autistic traits, and 150 healthy controls. Subjects were evaluated by trained psychiatrists, who performed a clinical diagnosis according to DSM-5 and then assessed with the AdAS Spectrum and the Autism Spectrum Quotient. RESULTS: Our results showed that the most discriminant cut-off scores were 70 for identifying subjects with full-blown ASD, and 43 for determining the presence of significant autistic traits. CONCLUSION: The threshold values proposed here showed satisfying levels of specificity and sensibility, as well as a good agreement with the diagnosis according to DSM-5 criteria, confirming the validity of the AdAS Spectrum as a psychometric tool for measuring ASD-related conditions in the clinical and general population.