Groundbreaking Study Reveals Equal Autism Rates Across Genders
A landmark international study has fundamentally challenged decades of medical understanding by revealing that women experience autism at the same rates as men, yet face significant under-diagnosis due to persistent clinical biases. The research, published in The BMJ, followed over 2.7 million individuals born in Sweden between 1985 and 2000, tracking their diagnostic journeys through to 2022.
The Shifting Gender Ratio in Autism Diagnosis
For years, autism spectrum disorder (ASD) has been widely perceived as predominantly affecting males, with historical estimates suggesting ratios as high as four boys diagnosed for every girl. This new comprehensive analysis demonstrates how this ratio has dramatically decreased over time and with increasing age at diagnosis. The study found that while children under ten still show approximately three to four boys diagnosed for each girl, a remarkable "female catch-up effect" occurs during adolescence.
By the age of twenty, autism diagnosis rates become "more or less equal for men and women," according to lead author Dr Caroline Fyfe, now based at the University of Edinburgh. The research team concluded that the male-to-female ratio may have decreased to such an extent that, in Sweden, it "may no longer be distinguishable by adulthood."
The Consequences of Under-Recognition in Women and Girls
The study highlights serious implications for autistic women and girls who remain undiagnosed or misdiagnosed. As they await proper recognition, many are "likely to be (mis)diagnosed with psychiatric conditions," particularly mood and personality disorders. This diagnostic oversight forces them to self-advocate for appropriate recognition and treatment as autistic patients, equal to their male counterparts.
Dr Judith Brown from the National Autistic Society emphasised the critical importance of these findings: "Historically, it was wrongly assumed that autistic people were mostly men and boys, but we now know that women and girls are more likely to 'mask' what is traditionally thought of as signs of autism." This masking behaviour makes identifying their challenges significantly more difficult for clinicians.
Clinical Biases and the Masking Phenomenon
Dr Steven Kapp, senior lecturer in psychology at the University of Portsmouth, explained the subtle behavioural differences that contribute to under-recognition: "Autistic women and girls have often been missed because of subtler behaviours from trends towards more imitation and masking, including more eye contact than male counterparts."
The research team explicitly states that "clinical biases contribute to under-recognition of women and girls," confirming what the autistic community has long advocated. These biases have real-world consequences, as misdiagnosed autistic women frequently develop co-existing mental health difficulties including anxiety and depression, often resulting from the exhaustion of constant masking and lack of appropriate support.
Broader Implications for Healthcare and Society
A linked editorial written by a patient and patient advocate stresses that studies like this are "essential to changing the assumption that autism is more prevalent in the male sex than in the female sex." The research reveals how lack of self-understanding may amplify lack of self-acceptance, with particular concerns about the over-representation of autistic females among people with anorexia.
Dr Brown concluded with a powerful statement about the study's significance: "This is why it's so vital that the experiences of autistic women and girls are not overlooked, and outdated stereotypes and incorrect assumptions are finally put to rest." Greater gender parity in autism diagnosis promises to promote more safety, wellbeing, and positive relationships for autistic women and girls across society.
