Researchers from the Autism Research Centre have proposed a new framework for the study of sex and gender differences and autism spectrum conditions. The team, led by Meng-Chuan Lai, systematically reviewed 329 articles discussing sex, gender, and females in relation to autism. Published in the Journal of the American Academy of Child and Adolescent Psychiatry, this review resulted in four levels of discussion of sex/gender differences in autism, ranging from descriptions and diagnoses in autism to specific biological mechanisms driving sex/gender differences in autism spectrum conditions.
The first level, termed “Nosological and diagnostic challenges”, discusses questions such as “How should autism be defined and diagnosed in females?”
The second level, “Sex/gender independent and sex/gender dependent characteristics”, covers questions of symptoms and characteristics of autism spectrum conditions that individuals of different genders experience distinctly.
The third, “General models of aetiology: liability and threshold”, discusses rates of autism in males and females, and how they can be explained by overall sex/gender differences, such as greater genetic variability in males.
Lastly, level four of the framework discusses specific biological mechanisms that could be driving sex differences in autism, such as the involvement of sex hormones in the aetiology of the disease.
The researchers argue that this new framework will make it easier to classify new studies on sex/gender differences in autism, and the scope of these studies. For example, level one could include qualitative research on female presentations of autism spectrum conditions, while level three could include identifying endophenotypic, genetic, and epigenetic factors associated with the increased diagnoses/traits in families of female compared to male probands.
This 4-level framework, they state, also helps in the identification of new research questions, as it clearly outlines gaps in current knowledge. In fact, the researchers go on to identify future work they consider necessary to help our understanding of sex and gender differences in autism research.
The authors also state: “Although we focus specifically on autism, the principles and issues discussed here could apply to other conditions that show sex/gender differences in prevalence, and/or that potentially have sex/gender-differential characteristics and etiological–developmental mechanisms.”