Bill Gates said he believes he would have been diagnosed with autism if he were growing up today.

The Microsoft co-founder and tech billionaire, 69, made the revelation in his upcoming memoir, “Source Code: My Beginnings.”

In an excerpt of the book, which was published in The Wall Street Journal, Gates wrote about how his parents “struggled with their complicated son” during his childhood in Washington State.

“If I were growing up today, I probably would be diagnosed on the autism spectrum,” Gates wrote. 

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“During my childhood, the fact that some people’s brains process information differently from others wasn’t widely understood.”

The term “neurodivergent,” which is widely used today, had not yet been coined while he was growing up, Gates noted. 

“My parents had no guideposts or textbooks to help them grasp why their son became so obsessed with certain projects, missed social cues and could be rude and inappropriate without seeming to notice his effect on others,” he went on.

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Gates wrote about how his parents, Bill and Mary Gates, gave him the “precise blend of support and pressure” he needed to develop his social skills.

“Even with their influence, my social side would be slow to develop, as would my awareness of the impact I can have on other people,” he wrote. “But that has come with age, with experience, with children, and I’m better for it.”

“I wish it had come sooner, even if I wouldn’t trade the brain I was given for anything.”

Signs of autism disorder 

The hallmark signs of autism are challenges with social communication skills and restricted and repetitive behaviors, according to Andy Shih, chief science officer at Autism Speaks in New York City. 

“This could look like avoidance of eye contact, delayed language development, difficulty understanding other people’s feelings, repeating words or phrases, hand flapping, or having very intense and specific interests,” he told Fox News Digital.

“I wouldn’t trade the brain I was given for anything.”

On the behavioral side, autism spectrum disorder can also manifest as a “rigid reliance on routines, an intense focus on specific topics or sensory sensitivities,” according to Jonathan Alpert, a psychotherapist in New York City. 

Autism is a spectrum, Alpert noted, which means symptoms can vary significantly in type and severity. 

Off the radar

Alpert confirmed that autism “wasn’t on peoples’ radar” as much when Gates was a child as it is today. 

“Autism wasn’t widely recognized or understood decades ago,” he said. “Back then, the diagnostic criteria were much narrower, and awareness was limited even among healthcare professionals.”

What is now known as the autism spectrum was categorized differently or overlooked entirely, Alpert noted. 

“As a result, many individuals who would meet today’s criteria for autism went undiagnosed.”

Shih agreed that autism diagnoses were much less common when Gates was growing up in the 50s and 60s. 

“Autism was first described by Leo Kanner in 1943, and while awareness grew slowly in the following decades, it wasn’t until the 80s and 90s that autism spectrum disorder was introduced into the DSM (the diagnostic manual used in the U.S.) and became widely recognized and diagnosed at higher rates,” he told Fox News Digital.

Reasons for rising cases

One in 45 adults in the U.S. are diagnosed with autism, Shih noted — more than ever before.

“Autism prevalence has risen due to increased public and professional awareness of autism, broader diagnostic criteria for autism, improved screening tools like the Modified Checklist for Autism in Toddlers (M-CHAT), and standardized screening processes,” he stated. 

“These factors have led to earlier detection and more diagnoses.”

The growing prevalence of autism is a highly debated topic, Alpert noted. 

“Much of the increase in autism diagnoses can likely be attributed to improved awareness, broader diagnostic criteria and better access to healthcare services,” he told Fox News Digital. 

“Autism wasn’t widely recognized or understood decades ago.”

Other factors, however — such as environmental exposures and genetic predispositions — are also being studied as potential contributors. 

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“While it’s essential to identify and support those with legitimate diagnoses, there’s also concern that over-diagnosis — potentially influenced by societal trends or misinterpretations by less experienced therapists — can trivialize the condition and undermine those truly in need of support,” Alpert cautioned.

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Despite the growth in diagnoses, there are still missed diagnoses, Shih noted.

The expert said, “While society is much more aware of autism today than ever before thanks to improved public health outreach and increased screening, advocacy and awareness efforts, there are still likely many adults with autism who never received a diagnosis or were misdiagnosed.”

Bill Gates’ memoir, “Source Code: My Beginnings,” will be published on Feb. 4 by Knopf.