Hidden population? A qualitative and quantitative search for a female-phenotypic presentation of autism

Abstract

Anecdotally, females with autism present differently from males. However, studies into autism tend to use a predominantly male sample, and make few gender-based comparisons. Hence, there is relatively little research on gender-specific presentations of autism. Furthermore, those studies that have been undertaken are equivocal in their findings. Should males and females with autism present differently, then the male preponderance in the research population may lead to a bias in our understanding of autism, and the diagnostic criteria it informs, creating circularity. This thesis aimed to investigate if and how females with autism present differently, while avoiding the problem of circularity. As diagnostic criteria for autism consider behaviour (potentially biased to favour males), the diagnosed samples of participants in studies will present with similar behaviours, regardless of gender. However, gender differences may persist in areas of cognition, such as block design. A literature review of gender differences among people with autism on the block design task revealed only one adequately powered study; this indicated a possible gender difference. To expand the data available, a meta-analysis of studies comparing people with and without autism on the block design task was carried out. Then, the ratio of males and females within autism and control groups was regressed as a proxy indicator of gender differences. This did not reveal any gender differences. An alternative approach was adopted within the research study. Through asking professionals highly experienced in diagnosing autism about gender differences in autism, it was hoped that they would express their own conception of autism, beyond the present diagnostic criteria, thereby avoiding circularity. A thematic analysis of interviews with 14 clinical psychologists with expertise in this area was conducted. Gender differences in presentation, but not underlying pathology, were noted by participants. Trans-diagnostic constructs such as social awareness and motivation were thought to drive the gender differences in presentation. However, although the presentation and constructs were gender biased, they were not gender-specific, suggesting a broader view of autism is needed beyond dichotomous gender differences.