Four times the numbers of males are diagnosed with a high-functioning autism spectrum disorder (ASD) than females. Alexandra Head, psychology PhD student at Deakin University (under the supervision of Professor Jane McGillivray), is investigating this gender variance and questions whether high rates of girls are in fact going undiagnosed.

What were your research methods and key findings?

A growing body of research focused on females with ASD questions the assumption of gender invariance in ASD. Clinical observations suggest that females with ASD superficially demonstrate better social and emotional skills than males with ASD, which may camouflage other diagnostic features. This may explain the under diagnosis of females with ASD.

We hypothesised that females with ASD would display better social skills than males with ASD on a test of friendship and social function. One hundred and one 10-16-year-olds (ASD females n = 25; typically developing (TD) females n=25; ASD males n=25; TD males n=26) were interviewed (using the Friendship Questionnaire (FQ)) with high scores indicating the child has close, empathetic and supportive relationships. One parent of each child completed the FQ to assess whether there are differences in perception of friendships between parents and children. It was found that independent of diagnosis, females demonstrated higher scores on the FQ than males. Further, regardless of gender, children with ASD demonstrated lower scores than TD children. Moreover, the effect of ASD was independent of gender. Interestingly, females with ASD and TD males displayed similar scores on the FQ. This finding is supported by clinical reports that females with ASD have highly developed facilities for mimicry and imitation, as well as more highly developed social skills than males with ASD. Further research is now required to examine the underlying causes for this phenomenon in order to develop gender-appropriate diagnostic criteria and interventions for ASD.

Why might girls be more adept at concealing autistic behaviours than boys?

At this stage, we are basing this notion on a lot of clinical anecdotes and parental reports. There is very little evidence as yet to back up these assertions; however, the research is starting to be published. One theory suggests that girls (one way or another) learn certain rules associated with social interactions faster than males or boys on the spectrum, which helps them integrate into social situations more easily.

What may prevent these children from being assessed for an autism disorder (or any mental health difficulty)? 

Based solely on my research, I would suggest that girls on the spectrum are more able to interact in a more socially-acceptable manner. I believe that further investigation into this area would reveal that clinicians, teachers and even sometimes parents make allowances for certain behaviours demonstrated by girls, simply because they are girls. The key is that we do not currently have a comprehensive idea of how girls with ASD present, which means that knowing what to look for is difficult. 

What are the lifetime impacts for a child with a non-diagnosis of high-functioning ASD?

Ultimately, the biggest impact of non-diagnosis is missing out on vital support and interventions. Starting early with certain interventions is really important to help children (and indeed adults) on the [autism] spectrum live life to the fullest and as independently as possible.

Based on your findings, would you recommend gender-specific diagnostic approaches for high-functioning autism?

The DSM-5 [The Diagnostic and Statistical Manual of Mental Disorders: Fifth Edition] has included a brief paragraph which mentions the gender "issue" within ASD. I believe that we need to spend more time exploring the differences (if any) that exist between males and girls on the spectrum. Based on the findings of these studies, I would suggest, at the very least, a review of how we can best identify girls on the spectrum. Ultimately, ASD is heterogeneous and one set of diagnostic criteria will never fit everyone. However, I believe that in general, we can do better at identifying girls on the spectrum. 

What is your general advice for educators and health professionals?

Research. Reading as much as possible from the scientific literature is really important. There are a number of highly respected researchers who are making important headway in the area of understanding girls on the [autism] spectrum. But [it’s important to] also understand that there is not one autism; rather, autisms. Even if we do develop a comprehensive understanding of how girls on the [autism] spectrum differ from boys, each child will be different.