Autism and Eating Disorders in Women: A Function of Age

Background: Some evidence suggests that eating disorders (EDs) and Autism Spectrum Disorders (ASD) may be related in women, though how these comorbidities differ across diagnosis and age is not well established. It was hypothesised that a) the relationship between ASD and anorexia nervosa would be stronger than other types of EDs, and b) the strength of the relationship between ASD and all EDs would decrease as age increased.

Objectives: To understand the nature of the relationship between ASD and eating disorders in adult women.

Methods: We recruited 897 women between the age of 18 and 68 (M=32.06, SD=9.41) online through specialist support services and social media. The sample contained N=551 typically developing women, N=151 with ASD, and N=195 with EDs. Self-declared diagnoses were confirmed by use of the Autism-Spectrum Quotient (AQ), and the Eating Attitudes Test (EAT-26).

Results: Data were stratified into two discreet age brackets. For those aged 18-34 years, Chi-square analysis found 45.5% of women with ASD also displayed high ED traits (χ²₍₁₎=20.27, p<.001, N=77), while 31.5% of women with an ED also displayed high ASD traits (χ²₍₁₎=9.99 p<.005, N=111). Multiple regression revealed that EAT-26 subscales Dieting, and Oral Control significantly predicted AQ scores, while Bulimia & Food Preoccupation did not. For the group aged 35+ years, Chi-square analysis found that women with and without ASD had similar levels of ED traits (χ²₍₁₎=3.75, p=.05, N=45, 31.1%), while women with and without an ED differed substantially in the proportion with high ASD traits (χ²₍₁₎=0.00, p=.964, N=37, 24.3%). Multiple regression revealed Dieting was the only significant predictor of AQ scores.

Conclusions: Over the age of 35, the relationship between ASD and EDs was non-significant, which is likely to be reflective of the younger age at which EDs are more prevalent (Ackard, Richter, Frisch, Mangham & Cronemeyer, 2013). The study was limited in that it only had the capacity to examine current ED traits, and not historical diagnoses of EDs, though this is an area in which further investigation is warranted. There also appears to be variation in the type of ED related to ASD among women, with anorexic symptomology having the greatest predictive power for ASD traits, which is consistent with existing literature (Huke, Turk, Saeidi, Kent, & Morgan, 2013). This study highlights the necessity for greater understanding of female specific ASD presentation.