The latest years of autism have made an effort to include more women and girls in their research. However, despite this hard work, most autism research consistently enrolls a small portion of female subjects or excludes them altogether, according to a new study.

Researchers from the Massachusetts Institute of Technology (MIT) earlier studies create a "leaky pipeline" that may result in severe underrepresentation of women in the studies of autism. According to MIT findings, a screening test commonly utilized to determine eligibility for studies of autism consistently winnows out a much higher rate of women than men.

The lack of women's representation makes it harder to develop useful interventions or provide correct diagnoses for women and girls, the researchers said.

John Gabrieli said that the findings favor a more inclusive approach and widen the lens to end up being less biased in terms of the participants in the research. Gabrieli is the Grover Hermann Professor of Health Sciences and Technology and MIT professor of brain and cognitive sciences. Professor Gabrieli added that the more understanding of autism in both genders and nonbinary individuals, the better the services and accuracy of diagnoses they can provide.

Professor Gabrieli, a member of MIT's Govern Institute for Brain Research, is the lead author of the research. The study was published in the journal Autism Research.

His fellow lead author of the paper, Anila D'Mello, is a former MIT postdoctoral researcher and assistant professor at the University of Texas Southwestern.

 The other co-authors of the research are MIT Technical Associate Isabelle Frosch, Research Coordinator Cindy Li, and Research Specialist Annie Cardinaux.

Female Subjects Exclusion

The spectrum of autism disorders is generally diagnosed based on traits observation such as repetitive behaviors with language difficulty and social interaction. However, doctors may use various screening tests to help them make a diagnosis.

In autism research, it is routine to use a screening test called the Autism Diagnostic Observation Schedule (ADOS) to tell eligibility for the study. The test assesses social interaction, communication, play, and repetitive behaviors. It provides a quantitative score in every category, and only the participants who will reach certain scores will qualify for inclusion in studies.

While conducting an exploratory study on how quickly the brains of autistic adults adapt to unusual events in the environment, the scientist in Gabrieli's laboratory noticed that the ADOS appeared to have different effects on male and female participation in the study. 

As the study continued, Professor D'Mello saw some important brain differences between the male and female participants in the study.

To probe the differences she saw, D'Mello tried to find more female subjects using the MIT database of autistic adults who have expressed interest in joining research studies. Although, when she sorted through the subjects, she found that only about half of the women in the database had met the ADOS qualifying scores, which are typically required for inclusion in autism studies, compared to 80% of the male subjects.

Professor D'Mello said that they realized there is a discrepancy and the ADOS is essentially screening out the possible participants in the research. They were surprised at how many males retained and many females lost to the ADOS screening. 

The scientist examined six publicly available datasets, to verify if this phenomenon was more widespread. The dataset participants include 40,000 autistic adults. In some of the said datasets, participants were screened using ADOS to determine their eligibility to participate in research. Moreover, for others, a 'community diagnosis-diagnosis from a medical professional or other health care provider was enough.

Early Autism Studies Exclude Women
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Family portrait - some children with neurodiversity - stock photo

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Researcher's Discovery

The scientists discovered that in the datasets that required ADOS screening, the ratio of men to women participants ended up being between 8:1. In contrast, in those required community diagnoses the ratio ranged from about 2:1 to 1:1.

Previous studies have found diversities in behavioral patterns in autistic males and females. But the ADOS screening test was originally developed using large male subjects, which may explain why the screening often excludes women from the research, D'Mello says.

She added that few females in the samples were used to create the assessment, so it may not be great at picking up the women's phenotype, which may differ in certain ways-primarily in the domain of social communication.

The Exclusion's Effect

According to MIT researchers, the failure to include more women in autism studies may contribute to shortcomings in the disorder definition.

Professor Gabrieli says that the way they perceived it is that the field evolved perhaps an indirect bias in how autism is defined and was driven disproportionally by analysis of males and their recruitment etc.

The indirect bias has led to documented hardships in receiving a diagnosis for women and girls, even though the symptoms are similar to those presented by autistic men and boys.

Many women might be missed in terms of diagnoses and their study shows that in the research plot, D'Mello says.

The women's exclusion from the research may lead to treatments that don't work well for them. It also may contribute to autism perception that doesn't affect women as much as men.

The MIT researchers are planning to further explore some of the gender and sex-based differences that appear in autism, and how they rise. Adding to that, they are also planning to expand the gender kinds. In the current research, the participant's survey asked them to choose female or male, but the scientist has updated their questionnaire to include transgender and nonbinary choices.

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