Gender Differences in Adult Outcomes for Individuals Diagnosed with ASD in Childhood

Background: Research in autism spectrum disorders (ASD) has historically focused on males, as they are diagnosed 4-to-5 times more often with the condition than females.  However, interest in females with ASD has been on the rise, with recent studies suggesting gender differences in the presentation of symptoms and associated behavioral features.  Research suggests that parents of girls with disabilities may provide their daughters with fewer opportunities to practice activities that encourage independent daily living skills, which may affect adult outcomes (Hogansen et al., 2008); however, few studies have examined how childhood daily living skills and other characteristics impact life outcomes of women with ASD. 

Objectives: The aim of this study was to examine gender differences in a variety of measures associated with well-being (e.g., employment status, daily living skills, quality of life) in adults with ASD, including how their childhood characteristics affected adult outcomes. 

 Methods: This project is part of a larger study examining adult outcomes of children diagnosed with ASD during childhood between 1970 and 1999.  Measures of ASD symptoms (CARS; Schopler et al., 1986), adaptive behavior skills (Vineland ABS; Sparrow & Cichetti, 1984), and IQ were assessed during childhood, and caregivers completed surveys assessing a variety of outcomes in their adult children, including independent daily living skills, quality of life (QoL), current ASD symptom severity, and employment status.  Participants included caregivers of 189 adults with ASD including 38 women and 151 men.  Women and men with autism did not differ on age, ethnicity, parent education level, or communication ability.

Results: In childhood, there were no gender differences in IQ scores or ASD symptom severity; however, girls with ASD scored lower on childhood Vineland standard scores than boys (t(186)=-2.99, p=.004).  In adulthood, women with ASD scored lower on the Waisman Activities of Daily Living Scale (Maenner et al., 2013) (t(187)=-2.9, p=.004) and on the QoL-Questionnaire (Shalock & Keith, 1993) (t(186)=-2.1, p=.04) than men.  Women (41.9%) were less likely to have been employed in the past two years (χ²=6.13, p=.05) than men (56.6%), and they exhibited higher scores on current ASD symptom severity (SRS-2; Constantino & Gruber, 2012) (t(182)=-2.8, p=.006).  When adult outcomes were examined while controlling for childhood Vineland scores, gender was no longer significantly related to the outcome measures, with childhood Vineland mediating all of the effects of gender on adult outcomes.        

Conclusions: Despite exhibiting similar childhood ASD symptom severity and intellectual functioning to males, females with ASD exhibited lower childhood adaptive behavior skills.  Poorer outcomes for females in adulthood were accounted for by differences in childhood adaptive functioning skills, suggesting that early gender differences in adaptive behavior may be at the heart of why women with ASD show more significant difficulties in adulthood than men.  It is unclear if these outcomes reflect fundamental gender differences in early adaptive skills or if they are due to gender differences in childhood experiences, parental expectations, and learning opportunities.  Future research in this area is needed to examine whether early intervention targeting adaptive skills may improve outcomes for females with ASD.