In the United States one in 68 children are affected by autism. Of these children, the majority diagnosed on the autism spectrum are male: according to the CDC approximately 4 boys for every girl. However, new research suggests that the criteria for diagnosing autism spectrum disorder (ASD) overlooks girls as the criteria are based on data sets taken almost entirely from studies on boys with autism. This means there may be even more children on the spectrum.1
Currently, the girls who are being diagnosed are diagnosed much later in life than their male counterparts. For instance, girls who have mild symptoms of autism are on average diagnosed two years later than boys. Misdiagnoses are also extremely common and in one case it took 10 years, 14 psychiatrists, 17 medications and 9 diagnoses before someone finally realized that the girl in question had autism.2 This is especially true for many “higher functioning” girls with autism so much so that they have been termed the “lost girls” or “hiding in plain sight.” Even when a girl's presentation is clearer, she may be overlooked. In one family, two siblings recieved an autism diagnosis but the girl's symptoms, though much more obvious than her brother's, "were waved off for three years by a variety of clinicians."3
Differences Between Genders
Since autism has historically been more common in boys than girls, scientists have focused their research on boys. This leaves us now with very little information on whether and how autism may present differently in girls than in boys.
New studies show there may even be slight differences between the core features of autism. A 2005 study at Stanford University suggests there is less repetitive and less restrictive behavior in girls than boys. This divergence can be partially explained by brain differences they found between autistic girls and boys. The study demonstrated differences in the patterns of gray matter in the regions responsible for the motor component of repetitive behaviors such as hand-flapping. Researchers were able to distinguish autistic boys from girls according to these patterns since the parts of the motor system that contributed to individuals scores for repetitive and restrictive behaviors were different in each gender.
Kevin Pelphrey, a leading autism researcher at Yale University's world-renowned Child Study Center, states that the brain-activity measures seen in autistic girls would not be considered “autistic” in a boy though they are “still reduced relative to typically developing girls.” In some ways the brain of an autistic girl may be more similar to that of a typical boy than a boy with autism. A 2014 study by Jane McGillivray and her colleagues, provides behavioral evidence to support this idea. McGillivray and her colleagues compared 25 autistic boys and 25 autistic girls with a similar number of typically developing children. On a measure of friendship quality and empathy, autistic girls scored as high as typically developing boys the same age but lower than typically developing girls.1
In addition, a 2014 study by Frazier and his colleagues suggest differences in play between the genders. It seems as though the pastimes and preferences of a girl with autism are much more similar to that of neurotypical girls than autistic boys. For instance, while an autistic boy may be obsessed with train schedules an autistic girl may be obsessed with Disney characters and American Girl dolls which might seem typical, not autistic. Even the absence of pretend play, one of the markers for autism, is seen to be less true for girls. For instance, Jennifer O'Toole, an author and founder of the Asperkids Web site and company, had behavior that “might have seemed like typical make-believe to her parents because she staged Barbie weddings just like other little girls. But rather than imagining she was the bride, O'Toole was actually setting up static visual scenes, not story lines.”1
However, the difference between typical and autistic development in girls may lie less in the nature of their interests than in its level of intensity. These girls may refuse to talk about anything else or take expected conversational turns. “The words used to describe women on the spectrum come down to the word ‘too,’” O'Toole says. “Too much, too intense, too sensitive, too this, too that.”
Disinterest in socializing is another hallmark of autism, so much so that it is specifically included in some diagnostic guidelines. Though it is sometimes found that autistic boys “do not care whether they have friends or not… autistic girls tend to show a much greater desire to connect.”1 It is thought that girls learn and work hard to disguise their symptoms, especially when they are younger, in order to be socially included. “Girls tend to get by,” Dr. Susan F. Epstein, a clinical neuropsychologist, says. “They might not understand what’s going on but they’ll try to just go along and imitate what they see. And they may get away with it to third grade or fifth grade, but once they get to junior high and high school, it shows as a problem.”3
Excerpt of O’Toole’s experience from the Scientific American's article "Autism It's Different in Girls":On the outside, she looked pretty much the opposite of autistic. At Brown University, she was a cheerleader and sorority girl whose boyfriend was the president of his fraternity. But inside, it was very different. Social life did not come at all naturally to her. She used her formidable intelligence to become an excellent mimic and actress, and the effort this took often exhausted her. From the time she started reading at three and throughout her childhood in gifted programs, O'Toole studied people the way others might study math. And then, she copied them—learning what most folks absorb naturally on the playground only through voracious novel reading and the aftermath of embarrassing gaffes.
As these girls age, they struggle to keep up with the elaborate rules of social relationships much more than their neurotypical counterparts. The effort of trying to blend in comes at a great cost to their inner selves which can be seen in increased rates of depression and anxiety in adolescents — 34 and 36 percent, respectively. A few studies have also found an intriguing overlap between autism and eating disorders such as anorexia, although the studies are too small to estimate how many women have both.2
It is important to note that the girls who continue to struggle with undiagnosed autism often develop depression, anxiety or poor self-esteem. Furthermore, these disorders and conditions may be harder to improve than usual as clinicians may not “really dig underneath to see the social dysfunction”3 caused by autism.
Though there is still a lot of research that needs to be done and resources that need to be allocated, there has been an uptick in the attention paid to the issues that affect women with autism in the past two to three years. More money is now available for scientists to study whether and how autism differs in boys and girls. The journal Molecular Autism has also dedicated two special issues to research exploring the influence of sex and gender on autism. “Almost overnight, we went from a couple of people talking about sex differences to everyone studying this as a major factor in the field,” said Pelphrey. Hopefully this shift will shed some much needed light on the undiagnosed girls with autism that have been “hiding in plain sight.”
1. Szalavitz, M. (2016, March 01). Autism--It's Different in Girls. Retrieved from https://www.scientificamerican.com/article/autism-it-s-different-in-girls/
2. Mandavilli, A. (2015, October 19). The lost girls. Retrieved from https://spectrumnews.org/features/deep-dive/the-lost-girls/
3. Arky, B. (n.d.). Why Many Autistic Girls Are Overlooked. Retrieved from https://childmind.org/article/autistic-girls-overlooked-undiagnosed-autism/