Author Interviews, Autism, BMJ, Parkinson's / 05.02.2026
Male:Female Ratio of Autism May Be More Equal Than Recognized
MedicalResearch.com Interview with:
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Dr. Fyfe[/caption]
Dr. Caroline Fyfe PhD
Postdoctoral Research Associate
Life Long Health and Wellbeing Theme
University of Edinburgh
MedicalResearch.com: What is the background for this study?
Response: Autism (ASD) has traditionally been seen as a condition that disproportionately affects males. This study quantifies the sex bias across birth cohorts, ages, and calendar time, using the Swedish national population registers to follow ~ 2.7 million individual born between 1985 and 2020 throughout their lives. Among children under ten years old the male-to-female diagnosis ratio remained relatively stable at about 3:1.
In contrast, a rapid increase in diagnoses of ASD among females during adolescence, produced a “female catch-up effect” that resulted in near parity of ASD prevalence between males and females by adulthood.
Dr. Fyfe[/caption]
Dr. Caroline Fyfe PhD
Postdoctoral Research Associate
Life Long Health and Wellbeing Theme
University of Edinburgh
MedicalResearch.com: What is the background for this study?
Response: Autism (ASD) has traditionally been seen as a condition that disproportionately affects males. This study quantifies the sex bias across birth cohorts, ages, and calendar time, using the Swedish national population registers to follow ~ 2.7 million individual born between 1985 and 2020 throughout their lives. Among children under ten years old the male-to-female diagnosis ratio remained relatively stable at about 3:1.
In contrast, a rapid increase in diagnoses of ASD among females during adolescence, produced a “female catch-up effect” that resulted in near parity of ASD prevalence between males and females by adulthood.
Applied Behavior Analysis (ABA) therapy is an evidence-based treatment for individuals with autism spectrum disorder and other developmental disorders. ABA therapy is a personalized treatment plan that focuses on improving behavior, social interaction, and more, simultaneously focusing on the person’s strengths and weaknesses. For this reason, it is crucial to plan the treatment effectively. While the treatment itself has been groundbreaking, it does come with a set of challenges. This article explores the challenges of ABA treatment planning with practical solutions.
Dr. Walsh[/caption]
Christopher Walsh, M.D., Ph.D.
Chief, Division of Genetics and Genomics
Bullard Professor of Pediatrics and Neurology at Harvard Medical School
and researcher who has used material donated to the brain bank
MedicalResearch.com: What is the background for this study?
Response: Many different types of genetic variants contribute to neurodevelopmental disorders such as autism. Copy number variants are large pieces of genetic material that are duplicated or deleted. We have known for many years that many copy number variants at certain genetic locations are linked to autism. Because these copy number variants may include lots of different genes, it has been difficult to understand how these copy number variants alter human brain function. Furthermore, although animal models are important, autism is in many ways defined by differences in uniquely human cognitive and social functioning. Better understanding of how these copy number variants change human brain function will shed light on universal mechanisms that regulate neurodevelopment. We studied a copy number variant called dup15q, that is associated with almost 40-fold higher rates of autism vs. the general population. We studied post-mortem human brain tissue from individuals with dup15q, individuals with autism not related to dup15q, and neurotypical controls, to better understand how the human brain is impacted by dup15q. We focused on frontal cortex, an important brain region in executive function and social perspective taking. We applied cutting edge techniques that allow us to assess individual cells in the brain. 
Dr. Pierce[/caption]
Karen Pierce, Ph.D.
Professor, Department of Neurosciences, UCSD
Co-Director, Autism Center of Excellence, UCSD
MedicalResearch.com: What is the background for this study?
Response: The mean age of ASD diagnosis and eventual treatment remains at ~52 months in the United States1 - years beyond the disorder’s prenatal origins2, and beyond the age when it can be reliably diagnosed in many cases3.
Currently the only way to determine if a child has autism spectrum disorder (ASD) is to receive a developmental evaluation from an experienced clinician (usually a licensed clinical psychologist). There are often long waiting lists, and only a small number of clinicians have the experience required to make early-age (i.e., between 12-36 months) diagnoses of ASD. Thus, there are many places in the country as well as world wide wherein children wait months or years to receive a formal diagnosis due to a lack of available expertise. Moreover, diagnostic evaluations are expensive and usually cost the parent and/or insurance approximately ~$2,000 or more per evaluation. Finally, clinical evaluations usually take between 2-3 hours to complete and result in fatigue for both the parent and toddler.
Eye-tracking, which generates biologically-relevant, objective, and quantifiable metrics of both visual and auditory preference profiles in babies and toddlers in just minutes, is a technology that can dramatically change how ASD is diagnosed.
Dr. Shoaff[/caption]
Jessica Shoaff, MPH, PhD
Postdoctoral Research Fellow and
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Dr. Korrick[/caption]
Susan A. Korrick, MD
Pulmonary and Critical Care
Assistant Professor in the Department of Environmental Health
Harvard Medical School · Harvard T. H. Chan School of Public Health
Brigham and Women's Hospital
Channing Laboratory Boston, MA 02115
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: Our study posed the question: Do teenagers’ exposures to chemicals that are often found in consumer products increase behaviors that are common among individuals diagnosed with Attention-Deficit/Hyperactivity Disorder (ADHD)? Our results suggest that teenagers exposed to chemicals often found in consumer products (particularly phthalates) may have increased behaviors that are common among individuals diagnosed with ADHD. However, we did not study the diagnosis of ADHD (most of our study teens did not have ADHD). This means our results cannot answer the question of whether these chemical exposures increase the likelihood of being diagnosed with ADHD. Also, in our study design, chemical exposures and ADHD-related behaviors were measured at the same time, so it is not possible to know with certainty whether the chemical exposures altered behavior or behavior altered chemical exposures. 
