Gender Differences in Medical and Behavioral Co-Morbidities in Children Ages 6-17 Years with ASD

Background:  ASD occurs 5 times more among boys (1 in 42) than girls (1 in 189).  The evidence for gender differences in regards to the behavioral presentation and co-morbid diagnoses between boys and girls with ASD is mixed. However, some previous research findings have yielded some gender differences, which has implications in the diagnosis and management of girls with ASD (Kirkovski, Enticott, & Fitzgerald, 2013; Frazier &  Georgiades, 2014, May, Cornish & Rinehart, 2013; Van Wijngaarden-Cremers et al, 2014) .

Objectives: This project is an observational study to determine if differences in the prevalence of medical and behavioral co-morbidities by gender in children ages 6-17 years with ASD exist.  

Methods:  Autism Speaks Autism Treatment Network Registry data contributed by 17 sites in North America was used for analysis.  The sample included 416 (15.29%) females and 2305 (84.71%) males with a diagnosis of ASD (Pervasive Developmental Disorder, Autistic Disorder and Asperger’s Disorder). Over 80% of the sample was Caucasian/White, 3.85% Asian, 6.88% African-American and 6.45% other/multiracial. Average age of the sample at the time of enrollment was 9.62 years (SD=2.81).  The outcome variables included severity of symptoms, adaptive functioning, behavioral presentation, and medical co-morbid diagnoses. Descriptive statistics or tabulations of outcome variables and covariates potentially associated with sex were run overall and by sex. Any potential outcomes and covariates with significant sex associations at the 0.05 level were analyzed using adjusted linear or logistic regression models. Race and IQ were included as covariates in subsequent adjusted models.  

Results:  Girls had a higher prevalence of obsessive-compulsive disorder and were less likely to be underweight. Girls were also reported to have a higher rate of behavioral challenges related to aggressive behavior, anxiety, and taste/smell sensitivities. In unadjusted analyses, ADHD medication use was lower among girls although the prevalence of ADHD was similar between boys and girls.  Girls also had lower calibrated ADOS severity scores. There were no differences between girls and boys regarding age of first concern and age of diagnosis.

Conclusions: Girls ages 6-17 years with ASD may present more often with OCD or behavioral challenges compared to boys. These differences in findings highlight the unique needs of girls with ASD and have important implications in their medical and behavioral care.  

Acknowledgment: This Network activity was supported by Autism Speaks and cooperative agreement UA3 MC11054 through the U.S. Department of Health and Human Services, Health Resources and Services Administration, Maternal and Child Health Research Program to the Massachusetts General Hospital. This work was conducted through the Autism Speaks Autism Treatment Network.