Summary: The study reports that girls and boys have similar rates of ASD concern and identifies several biases contributing to the inflated sex ratio for the diagnosis of autism. The findings could aid in the early identification of girls on the autism spectrum.
Source: University of Minnesota
Posted in Biological psychiatrya multidisciplinary study conducted by the University of Minnesota has demonstrated that an equal number of girls and boys can be identified as having autism spectrum disorder (ASD) problems when screened earlier, correcting for the large differences gender in current diagnostics.
“The conventional wisdom is that more boys than girls have ASD,” said the study’s lead author. Casey BurrowsPh.D., LP, assistant professor at the University of Minnesota Medical School and psychologist at M Health Fairview.
“Our research shows that girls and boys have similar rates of concern for ASDs and identifies some of the biases contributing to inflated sex ratios. We hope this research brings relief to women and girls who have struggled socially without knowing why.
Using data from the Infant Brain Imaging Study Networkthe study used a less biased sample that followed a group of children more likely to develop ASD (for example, infant siblings of children with autism) from six to 60 months.
The study found that there are as many girls identified as having ASD-related problems when children are screened early and when they are corrected for gender-based biases in diagnostic instruments. This contrasts sharply with the current sex ratio of 4 to 1 when following standard clinical referral processes.
“We know that screening processes and diagnostic tools for ASDs are often lacking for many girls who are later diagnosed with ASDs,” said Dr. Burrows, who is also a member of the Masonic Institute for Brain Development.
“This prevents many girls from receiving early intervention services at a time when they can have the greatest impact on early childhood. Most ASD studies focus on children after they are diagnosed, lacking information about symptoms in children that are missed by common screening practices.
The research team looked at whether girls and boys had similar symptoms and found subtle differences in the structure of core ASD symptoms. After correcting for these differences, subgroup analysis identified a “very concerning” group that had a male to female sex ratio of 1 to 1.
According Jed EllisonPh.D., associate professor at the Institute of Child Development and Medical School and co-author of the article.
“It is imperative to recognize and understand the limitations of traditional diagnostic and screening approaches and to generate creative solutions to identify all children who could benefit from early intervention services.”
The researchers plan to follow up on this work by examining how children in the high social concern group fare from primary to secondary school. They are also studying group differences in underlying brain structure and function.
Funding: This study was supported by grants from the National Institutes of Health (R01-HD055741, R01-MH118362-01, R01-MH118362-02S1, U54-HD079124, P50-HD103573 (project ID 8084), U54-HD086984), Autism Speaks , and the Simons Foundation (140209). Dr. Burrows was supported with an NIH Career Development Award (K12-HD055887).
About this autism research news
Author: Kat Dodge
Source: University of Minnesota
Contact: Kat Dodge – University of Minnesota
Image: Image is in public domain
Original research: Access closed.
“A data-driven approach in an unbiased sample reveals an equivalent sex ratio of autism spectrum disorders associated with impairment in early childhood” by Casey Burrows et al. Biological psychiatry
Data-driven approach in unbiased sample reveals equivalent sex ratio of autism spectrum disorders associated with impairment in early childhood
Gender differences in the prevalence of neurodevelopmental disorders are particularly evident in autism spectrum disorders (ASD). The heterogeneous presentation of symptoms and the potential for measurement bias hinder the early detection of ASD in women and may contribute to divergent prevalence estimates. We examined social communication (SC) and restricted and repetitive behavior (RRB) trajectories in a sample of infant siblings of children with autism, adjusting for measurement bias based on age and sex. We hypothesized that taking advantage of a prospective high family probability sample, deriving behavioral constructs based on the data, and accounting for measurement bias would reveal less discordant sex ratios than those typically seen in ASD.
We performed direct assessments of ASD symptoms at 6-9, 12-15, 24, and 36-60 months (total Ncomments= 1254) with infant siblings of autistic children (N = 377) and a lower ASD family likelihood comparison group (N = 168; Ncomments=527). We established the invariance of measures by age and sex for separate models of SC and RRB. We then modeled latent class growth mixture with the longitudinal data and assessed gender differences in trajectory membership.
We identified two latent classes in the SC and RRB models with equal sex ratios in the high concern group for SC and RRB. Gender differences were also observed in the high SC concern group, indicating that girls categorized as “high social concern” have milder symptoms than boys in this group.
This novel approach to characterizing ASD symptom progression highlights the utility of assessing and adjusting for sex-related measurement biases and identifying sex-specific symptom emergence patterns.