Gender Differences In Presentation of Autism Spectrum Disorders

Background: It is well established that the incidence of Autism Spectrum Disorders (ASD) is higher in males than females, with ratios estimated as high as 4:1 (Fombonne, 1999).  However, differences that may occur between genders in developmental profiles or clinical presentation of ASD are not fully understood.  Numerous studies have found gender differences in IQ (Carter et al., 2007; Banach et al., 2009; Volkmar et al., 1993; Lord et al., 1982), but these results have been variable.

Objectives: Through exploratory analyses, this study will further examine sex differences among individuals diagnosed with ASD.

Methods: Over 240 families, with at least one child clinically diagnosed with ASD, have been enrolled in our study.  Participating children ranged in age from two to eighteen years (203 males, 39 females). A comprehensive battery was used to assess the cognitive and social functioning of the children with ASD.  ASD diagnostic information was collected through direct observation and parental report, including the Autism Diagnostic Observation Schedule (ADOS), and the Autism Diagnostic Interview (ADI). We examined various characteristics of ASD clinical presentation, including social communication, interaction skills, and repetitive and stereotypical behaviors with respect to gender.  We also looked at aspects of developmental functioning, including verbal, nonverbal, motor, and adaptive skills as well as psychopathological and maladaptive behaviors.

Results: Our data supports previous research that males with ASD tend to have higher IQ than females with ASD. In addition, we found that males and females did not differ in their presentation of ASD. In our sample, females demonstrated more autistic behaviors as reported on the Social Responsiveness Scale, however, these differences were not detected in our other behavioral measures.

Conclusions: Although our behavioral measures did not indicate significant gender differences in the presentation of ASD, in our next round of analyses we plan to further expand our data set, as well as to explore whether sex differences vary among individuals with or without a family history of ASD.