Why girls are underdiagnosed with autism — as Grimes, 37, reveals she just found out she’s on the spectrum

At 37 years old, Grimes is finally connecting the dots.

“Got diagnosed [with] ADHD/autism this year and realized I’m prob dyslexic, which is why I can’t spell at all without spellcheck,” the Canadian singer recently shared on X, reflecting on how an earlier diagnosis might have affected her childhood.

Her revelation underscores a troubling trend: Autistic girls and women are often diagnosed much later in life — or not at all. Here’s everything you need to know about why so many are falling through the cracks.

The gender divide

CDC data shows that roughly one in 36 US children has autism, with traditional estimates indicating that the disorder is four times more common in boys than in girls.

However, experts are starting to challenge that ratio, with recent research suggesting nearly 80% of autistic females remain undiagnosed by age 18, according to UCLA Health.

Why the gap? Since there’s no medical test for autism, doctors depend on a person’s developmental history and behavior to make a diagnosis. But since most autism research has traditionally focused on males, what we know about the disorder is largely based on how it manifests in boys.

When it comes to women, the way autism presents is “not very obvious,” Dr. Sanjeev Kothare, division director of pediatric neurology at Cohen Children’s Medical Center, told The Post. 

“In general, men have more severe communication and social problems, including repetitive behaviors and externalizing problems like ADHD,” Kothare said. “Females present with less communication issues and repetitive behaviors, but exhibit more anxiety and depression.”

In fact, girls on the spectrum may even seem ahead of their peers.

“Girls with autism typically show language skills that may appear advanced for their age, which ironically can lead parents and teachers to overlook potential developmental concerns,” said Ralph Moller, director of operations at Above & Beyond Therapy. 

Experts say women with autism are also often more adept at developing strategies to mask their autism traits, making it harder for doctors to spot. 

“When a girl shows difficulties with social relationships but has learned to mask them, it’s easy to dismiss her struggles as shyness or anxiety rather than a sign of something else, including autism,” Moller added.

The consequences of a late diagnosis

Though experts can identify autism as early as age 2, research suggests that girls are typically diagnosed 18 months later than boys and are much more likely to receive a “late diagnosis” (at 13 or older).

Many women who are diagnosed later in life report feeling like they never quite fit in or that something was “wrong” with them, which often leads to struggles with self-esteem, isolation, anxiety and depression, according to the Child Mind Institute.

Without a diagnosis, experts warn that girls on the spectrum often miss out on vital support that helps them understand their challenges and develop coping strategies, which can have long-lasting negative effects later in life.

Autism signs in women

According to Kothare, female adults with autism often retreat inward, struggling to maintain or initiate relationships and preferring solitude.

This often stems from difficulty reading and responding to social cues, leaving them feeling anxious and self-conscious about their behavior.

Additionally, many women with autism self-isolate due to sensory sensitivity, where heightened senses — like smell, light, sound or touch — make it challenging to tolerate external triggers.

Autism can also affect the ability to stay organized, finish tasks or manage emotions. In childhood, girls with autism frequently develop intense interests, a trait that can continue into adulthood.

Repetitive behaviors, or “stimming,” are another key characteristic. While men may rock or flap their hands, women’s stimming can appear more refined and socially acceptable, such as skin picking or hair twirling, according to UCLA Health. 

Coexisting conditions, including anxiety, ADHD, depression, OCD and tic disorders, are also more common in females, particularly those diagnosed later in life. 

Autism signs to watch for in girls

In addition to the traits seen in adults, Moller said girls with autism often exhibit advanced language skills for their age, which can lead parents and teachers to overlook potential developmental concerns. 

Mimicking others is another common sign. Girls with autism may copy social behaviors, such as forcing themselves to make eye contact because they’ve learned it’s expected in neurotypical conversations.

While this can make blending in easier, maintaining this act can be draining. This is why, Moller said, it’s common for girls on the spectrum to experience emotional meltdowns once they return home after social outings. 

“If this happens once or twice, it’s probably nothing to worry about, but if these meltdowns become a trend, and are combined with other signs of autism, it could be worth paying closer attention,” he said.