Why are autism symptoms different in women

Gender bias in diagnostics: autism could go undetected in girls

Boys suffer from autism significantly more often than girls. This is a common belief about developmental disorder. In the United States, for example, there is only one autistic girl for every four boys with autism. This incidence of the disease in boys suggests that there are genetic factors that make them more likely to develop autism. However, according to new research, this is only partially responsible for the unequal relationship. In addition, there is increasing evidence that there is a gender bias in the diagnosis of the disease, which could lead to autism spectrum disorders in girls not being diagnosed until later or not at all.

The common characteristics of autism are withdrawnness, obsessive behavior, and highly focused interests, such as collecting stones or an excessive interest in train timetables. Some recent studies indicate that these very "typical" characteristics of autism in children are more focused on symptoms and behaviors that occur in autistic boys but not in girls with autism. According to some researchers, this is mainly due to the fact that most of the studies on the topic were mainly carried out using samples with autistic boys. The symptoms determined from this would therefore perhaps not apply to girls and women at all.

Girls play differently

In a study recently published in the specialist magazine "Autism", the authors analyzed the behavior of children with and without a diagnosis of autism in the schoolyard. To do this, they observed a total of 96 children, 48 boys and 48 girls. Half of the children were autistic. Through their observations, the study authors found that the behavior of normally developing boys deviated more from that of autistic boys than the behavior of normally developing girls from that of their autistic classmates.

This was shown above all by the fact that the autistic boys played disproportionately more often alone and took part significantly less in the "typical" group games of their peers. It is therefore relatively easy for the untrained eye of a teaching staff to recognize when a boy is showing behavior that could be a sign of autism.

Camouflage makes diagnosis difficult

In the group of girls observed, the result was different. It is part of the "typical" behavior of girls in the school yard that they tend to play less team sports, chat more and, above all, switch between several activities during a break. The groups they form are usually smaller than those of the boys, and different social rules apply to who can and cannot be a part of it.

The girls seemed to recognize these social norms despite autism and imitated the behavior of their female colleagues much better than the boys and were hardly ever alone. The researchers summarize this behavior under the term "camouflage". These results suggest that autistic girls are better at hiding their illness than boys. This could be one reason fewer girls are diagnosed with Autism Spectrum Disorder (ASD).

Big differences in Asperger's Syndrome

In the case of highly functional autism or Asperger's syndrome, i.e. autism in which the affected person still has an IQ greater than 70, the difference in diagnosed cases between boys and girls is particularly large; the ratio here is 9: 1. A study from 2014 tried to find out why the difference is so great in this form of autism. The researchers assumed two possible, non-mutually exclusive hypotheses. Either this form of autism is particularly closely related to the genetic prerequisites for the disease, or the diagnosis for this form of autism is particularly focused on symptoms in male patients and thus complicates the diagnosis in girls and women.

The results provide evidence that both hypotheses are correct. Especially with highly functional autism, repetitive behavior and strongly focused interests are important features in diagnostics. According to the study, both symptoms are significantly less common in girls with this form of autism than in boys.

Autism and behavioral problems

Researchers in a 2012 study in which 15,000 pairs of twins were analyzed found that girls with the same number of autistic characteristics as boys had to show other behavioral problems or significant intellectual difficulties in order to be diagnosed using two diagnostic criteria commonly used in the USA receive.

One of the study's authors, Francesca Happé, also suggests that because of how different the symptoms of autism in girls are from those in boys, they are often seen as a sign of another disease. In autistic girls, therefore, there is often a misdiagnosis of, for example, ADHD, an obsessive-compulsive disorder or in some cases even anorexia, even though it is actually autism.

A study that focused specifically on diagnostic factors also showed that girls were more likely to be diagnosed with autism if their symptoms were more pronounced or similar to those of boys with autism. Based on their results, the researchers also suspect that other behavioral problems, such as hyperactivity or emotional difficulties, make girls more likely to be diagnosed with autism. Here, the research team sees the risk that girls, in whom no such abnormalities are noticed, will be diagnosed too late or not at all.

The results of the study also suggest that the parameters for diagnosing autism in children make those in girls more difficult. They are more geared towards the abnormal behavior of boys, and this makes it more difficult for laypeople such as parents or teaching staff to recognize autism in girls. Since the diagnosis of autistic children is very often initiated by teaching and support staff at schools or the like, their ability to recognize symptoms is of great importance. (jvs, 10.8.2017)