Gender Differences in ASD Symptoms in Adults with High Functioning Autism Spectrum Disorders

Background:  Autism spectrum disorders (ASD) are diagnosed about four to five times more frequently in males than in females.  Consequently, much of the early ASD research focused exclusively on males.  Only recently have gender differences in the presentation and characterization of ASD gained momentum in the literature.  This burgeoning body of research suggests that gender may affect the presentation of ASD, leading to a “gender-specific” ASD phenotype, in which females present with a different pattern of socio-communicative impairments and restricted interests and behavior than males.   

Objectives: The aim of this project is to examine gender differences in adults with high functioning autism spectrum disorders (HFASD) in self-report and parent-report ASD questionnaires, and in an observational assessment of ASD symptoms, as well as correlations among these different types of ASD measures.

Methods:  This project is part of a larger study examining gender differences in ASD symptoms, social relationships, and emotions in adults with HFASD.  Data collection is still in process, and it is expected that by the time of the conference in May 2013, there will be data for 60 participants with HFASD, 30 women and 30 men matched on age and verbal IQ.  Participants were recruited from several local organizations serving individuals with ASD and their families.  Parents of potential participants completed the high-functioning Autism Spectrum Screening Questionnaire (ASSQ), a screening measure for HFASD that was adapted for use with adults in this study, and the ASSQ-GIRL, an addition to the ASSQ recently developed to assess ASD features that may be more applicable to females with ASD.  Participants completed the Autism Spectrum Quotient (AQ), a self-report ASD screening measure.  Researchers assessed participants with the Autism Diagnostic Observation Schedule-2^nd Edition (ADOS-2) and the Wechsler Abbreviated Scale of Intelligence-2^ndEdition (WASI-2) to confirm that intellectual disability (ID) was not present.  Participants included 20 adults (12 women and 8 men) with a mean age of 26.4 years (SD=5.5 years), who had been diagnosed with an ASD by clinical psychologists, psychiatrists, and other medical professionals, per parent report.  Men and women with HFASD did not differ significantly on age, living situation, ethnicity, employment, or WASI-2 verbal comprehension index scores. 

Results: There were no significant differences between men and women on ASSQ, AQ, or ADOS total and domain scores.  However, women did score higher on the ASSQ-GIRL (mean = 16.3, SD = 6.3) scale than men (mean = 11.3, SD = 5.4), and there was a trend towards significance (t=1.87, p=.078) with a large effect size (Cohen’s d=0.86).  ASSQ-GIRL scores and the ADOS-2 communication domain score were significantly negatively correlated (r = -.54, p= .014), suggesting that as ASSQ-GIRL scores increased, deficits in communication decreased.  

Conclusions:  Preliminary results from the study suggest some important gender differences.  Women scored higher on the ASSQ-GIRL, and this measure was associated with lower communication deficits on an observational measure of ASD symptoms.  These results suggest that the ASSQ-GIRL may add important information to the assessment and characterization of females with HFASD.