Underdiagnosis of girls with Autism and ADHD.
The signs of some disorders often go less noticed in girls due to the symptoms presenting differently, less obviously, or because girls are socialised in a way that they can conceal their difficulties better.
One disorder with a high prevalence of this issue is Autism, which is a pervasive developmental disability (PDD) characterised by “impairments in social and communicative abilities, along with the presence of ritualistic and/or repetitive behaviours” . The disorder is dominated by a high level of diagnoses in males compared to females, with a ratio of 4.5 to 1  and 10 to 1 for high functioning cases . However, there is growing evidence that it is more common in girls than had previously been believed. Due to the average female with autism displaying higher abilities in communication and socialising, and the normalisation of other symptoms like shyness and oversensitivity in the general female population, those on the spectrum are often concealed from diagnosis
Although there are some similarities in the way Autism presents in males and females, the reason for the underdiagnosis of females appears to lie in the differences. Studies have shown that females with autism who do not display additional intellectual or behavioural problems often do not fit the diagnostic criteria . This has been thought to be down to the criteria and its supporting research, which is largely based on typically male symptoms of autism, such as restricted interests, poor imitation, and externalising behaviour . Although these symptoms are not absent in females with autism, they present differently, appear less atypical, and so are harder to detect using the standard diagnostic criteria.
Young girls with Autism tend to camouflage their social symptoms through mimicking others in social situations and having higher control over their emotions, whereas young boys display more disruptive behaviour and hyperactivity , as well as social withdrawal and isolation . Where social symptoms are ‘masked’, there are many cases where teachers are unable to detect signs or indications of Autism in girls, however for parents, this is not the case. The term “4 o’clock explosion” was coined to describe how upon returning home children must release the feelings they’ve kept locked up for the whole day at school. This leads to parents having a markedly different view of their child than teachers and being disbelieved when they talk about their children’s behaviour to professionals .
For this reason, there is evidence to show that compared to boys, Autism is diagnosed much later in cognitively able girls, despite there being no difference in the number of visits to a health-care professional during the diagnostic process  and no difference in the age at which parents first express concern .
Another neurodevelopmental disability that displays a similar gender disparity in diagnosis is Attention Deficit Hyperactivity Disorder (ADHD). Girls with ADHD are more likely to have the inattentive type formerly known as ADD . This presents with less disruptive symptoms than the hyperactive type more common in boys which often lead to more behavioural problems. ADHD in girls often presents with hypersensitivity, poor attention and social anxiety as well as perfectionism  . Where symptoms of ADHD in boys typically present as behavioural issues, symptoms in girls such as inattentiveness, indecisiveness and emotional sensitivity often go unnoticed, leading to underdiagnosis and undertreatment of ADHD in young girls.
This leads to more negative long-term effects in girls with ADHD. For example, having no external factors to account for their social and academic problems, females with ADHD are much more likely to develop issues with self-esteem, depression, anxiety and eating disorders later in life . The longer wait for diagnosis means many young girls with ADHD are forced to suffer in silence until much later in life.
The solution to bridge the gap in diagnosis is to first educate carers and teachers how to recognise the less stereotypical signs of ADHD/Autism that present more often in girls. This will improve referral rates of suspected cases to specialists who can also work with both the school and the parents to ensure their children are receiving sufficient treatment and support. Some consider official diagnosis a negative thing but actually “In fact, 56 percent of the girls in our survey said that they felt better after finally having a name for what they felt. Only 15 percent said they felt worse. For most, it was a relief to find out they weren’t lazy, crazy, or stupid .”
1. American Psychiatric Association (2013) Diagnostic and Statistical Manual of Mental Disorders. 5th ed. Arlington, VA: American Psychiatric Association.
2. Ormond S, Brownlow C, Garnett MS, Rynkiewicz A, Attwood T. Profiling Autism Symptomatology: An Exploration of the Q-ASC Parental Report Scale in Capturing Sex Differences in Autism. J Autism Dev Disord. 2018 Feb;48(2):389-403. doi: 10.1007/s10803-017-3324-9. PMID: 29052806.
4. Dworzynski, K., Ronald, A., Bolton, P., & Happé, F. (2012). How different are girls and boys above and below the diagnostic threshold for autism spectrum disorders?. Journal of the American Academy of Child and Adolescent Psychiatry, 51(8), 788–797. https://doi.org/10.1016/j.jaac.2012.05.018
5. Hiller, R. M., Young, R. L., & Weber, N. (2016). Sex differences in pre-diagnosis concerns for children later diagnosed with autism spectrum disorder. Autism : the international journal of research and practice, 20(1), 75–84. https://doi.org/10.1177/1362361314568899
6. Mandy, W., Chilvers, R., Chowdhury, U., Salter, G., Seigal, A., & Skuse, D. (2012). Sex differences in autism spectrum disorder: evidence from a large sample of children and adolescents. Journal of autism and developmental disorders, 42(7), 1304–1313. https://doi.org/10.1007/s10803-011-1356-0
7. Siklos, S, Kerns, KA (2007) Assessing the diagnostic experiences of a small sample of parents of children with autism spectrum disorders. Research in Developmental Disabilities 28(1): 9–22.
8. Begeer, S, Mandell, D, Wijnker-Holmes, B (2013) Sex differences in the timing of identification among children and adults with autism spectrum disorders. Journal of Autism and Developmental Disorders 43: 1151–1156.