Hiding in Plain Sight: Eating Disorders, Autism, and Diagnostic Overshadowing in Women

Background: Autism and elevated autistic traits are increasingly identified in eating disorder (ED) populations, although less research has focused on ED rates and risk factors in individuals who already have an autism diagnosis. This study aimed to investigate the timing and sequence of autism and ED diagnoses in women and examined associations between autistic traits, autism diagnosis, and risk of EDs and other mental health difficulties. Method: In this cross-sectional study, we recruited 371 cisgender autistic women ( M age = 34.38 years, SD = 10.54) and 394 cisgender non-autistic women ( M age = 33.49 years, SD = 10.40). We used the Autism Spectrum Quotient to measure autistic traits, the Eating Attitudes Test to assess ED risk, and the Depression, Anxiety, Stress Scale for broader mental health concerns. We used chi-square tests to establish the rate of overlap between autistic traits, autism diagnosis, and mental health risks and linear regression models to assess the unique impact of autistic traits and autism diagnosis on mental health symptom severity. Results: We found that 58% of women with high autistic traits (with and without an autism diagnosis) were at high risk of an ED ( N = 174). While autistic traits predicted elevated ED risk overall, the effect was substantially lower in women with a formal autism diagnosis b = −8.34, t(718) = −5.84, p < 0.001, suggesting a potential protective factor. This finding was particularly notable, as approximately one-third ( N = 106, 28.6%) of diagnosed autistic women reported a history of EDs. Critically, however, in 75% of these cases, an ED diagnosis preceded an average delay of 13.86 years ( SD = 9.76) before they were identified as autistic. Higher autistic traits were also associated with increased depression, anxiety, and stress symptoms, with less severe depression levels again found in women with a formal autism diagnosis b = −1.70, t(718) = −3.27, p = 0.001. Discussion: Our findings underscore the urgent need for clinicians to screen women presenting with an ED for autism, as a formal diagnosis may improve their mental health-related outcomes. While we found that most autistic women were initially diagnosed with an ED and faced substantial delays before their autism was recognized, those diagnosed with autism first were 17 years old on average, indicating that their diagnoses were also delayed. Future research should therefore investigate differences in mental health outcomes in a broader range of autistic people, including gender-diverse individuals and those diagnosed in both childhood and adulthood.