A quarterly publication of the Autism Research Institute
Fall, 2022 | Number 4, Volume 36
Most studies on autism spectrum disorders (ASD) include very few female subjects—an issue that could significantly affect the validity of research findings for women with ASD—and a new paper suggests that this dearth of female subjects stems in large part from the use of one specific screening test.
While enrolling participants in their own research, Anila D’Mello and colleagues observed that the Autism Diagnostic Observation Schedule (ADOS) appeared to have unequal effects on male and female participation. Analyzing an MIT database of adults with ASD who had expressed interest in participating in research studies, they found that approximately half of the females in the database met the ADOS cutoff scores typically required for inclusion in autism studies, compared to 80 percent of the males.
D’Mello says, “We realized then that there’s a discrepancy and that the ADOS is essentially screening out who eventually participated in research. We were really surprised at how many males we retained and how many females we lost to the ADOS.”
To investigate this issue further, the researchers examined six other datasets including more than 40,000 adults diagnosed with ASD. They found that in datasets that required ADOS screening for eligibility, the ratio of male to female participants was around 8:1. In datasets that required only a community diagnosis, the ratios ranged from around 2:1 to 1:1. “These results,” the researchers say, “provide evidence for a ‘leaky’ recruitment-to-research pipeline for females in autism research.”
D’Mello notes that the ADOS was originally developed using a largely male sample, which may explain why it excludes many women. She says, “[It] might be that it’s not great at picking up the female phenotype, which may differ in certain ways—primarily in domains like social communication.”
She concludes, “If the research is saying that there aren’t females with autism, or that the brain basis of autism only looks like the patterns established in males, then you’re not really helping females as much as you could be, and you’re not really getting at the truth of what the disorder might be.”
“Exclusion of females in autism research: empirical evidence for a ‘leaky’ recruitment-toresearch pipeline,” Anila M. D’Mello, Isabelle R. Frosch, Cindy E. Li, Annie L. Cardinaux, and John D.E. Gabrieli, Autism Research, August 22, 2022 (free online). Address: Anila M. D’Mello, McGovern Institute for Brain Research, Massachusetts Institute of Technology, 43 Vassar Street, Cambridge, MA 02139, [email protected].
—and—
“Studies of autism tend to exclude women, researchers find,” news release, Anne Trafton, Massachusetts Institute of Technology, September 8, 2022.
