A comparison of the presentations of males and females with autism spectrum disorder and those narrowly below the diagnostic threshold

Little is currently known about the autism spectrum disorder (ASD)-related difficulties of females narrowly below the ASD diagnostic threshold and whether the disorder conceptualisation should be broadened to capture their presentations. We extracted fine-grained information from the assessment reports of 222 children who were either diagnosed with ASD (n = 156) or not diagnosed despite many ASD traits (n = 78). Females were less likely than males to meet Criterion B3 (restricted interests), and this was especially the case for subclinical (non-ASD) females. Non-ASD females lacked sufficient atypicality for diagnosis in several key domains, particularly Criterion A1 (social-emotional reciprocity). Evidence of sex/gender¹-specific restricted interests and stereotypical behaviours was found. Many behaviours differed in the extent to which they predicted the ASD diagnostic result for males and females, perhaps suggesting that sex/gender influences how ASD-related behaviours are perceived. We discuss these findings in the context of underdiagnosis of ASD in females and propose adjustments to assessment protocols. 

Lay Abstract: Most research about autism spectrum disorder (ASD) in females has looked at autistic features in people who have already received diagnoses. Because our understanding of ASD has been shaped by the difficulties of males, females may experience different difficulties and may not meet the criteria for diagnosis because of a skewed concept of ASD. We extracted detailed information from the assessment reports of 222 children who were either diagnosed with ASD (156 children) or not diagnosed despite many ASD traits (78 children). Females were less likely to have restricted interests, especially females who did not receive an ASD diagnosis. Females who did not receive an ASD diagnosis tended to show more ability in social and emotional reciprocity than what would qualify them for a diagnosis. We also found sex-/gender-specific profiles of body use and speech mannerisms. Many behaviours were more closely linked with an ASD diagnosis for males and others for females, suggesting that behaviours may be interpreted differently depending on the child’s sex/gender. We discuss implications for assessing females for ASD in the context of this evidence.