In choosing to unveil a report about autism in the Roosevelt Room of the White House — an august setting just off the Oval Office — President Trump sent Americans a message: For him, the issue is personal.
“I always had very strong feelings about autism,” Mr. Trump began on Monday, saying he had been waiting for such an event for 20 years. Later, Mr. Trump proclaimed: “I’ve stopped seven different wars. I’ve saved millions of lives. I’ve done a lot of things. This will be as important as any single thing I’ve done.”
On and off for an hour, with his health secretary, Robert F. Kennedy Jr., and other top health officials beside him, Mr. Trump delivered impassioned — if scientifically dubious — remarks about the rise in autism, calling it “among the most alarming public health developments in history.”
He spouted flawed medical advice about vaccines and delivered pointed instructions to pregnant women not to take the painkiller and fever reducer acetaminophen, the active in ingredient in Tylenol, which he said may cause autism in babies. He recommended parents space out vaccine shots for their babies, contradicting the current immunization schedule. He acknowledged he was going further than Mr. Kennedy and Dr. Marty Makary, the commissioner of the Food and Drug Administration, whose carefully calibrated remarks prompted the president to concede he did not have all the facts.
“We’re making these statements, and I’m making them out front, and I’m making them loud, and I’m making them strongly, not to take Tylenol, not to take it, just don’t take it unless it’s absolutely necessary — and there’s not too many cases where that will be the case,” Mr. Trump said.
“And again, what’s the worst? The worst is nothing can happen,” he said, though fevers in pregnancy can be dangerous for both the mother and the fetus.
Mr. Trump’s interest in autism dates at least to December 2007, when he hosted leaders of the advocacy group Autism Speaks at his Mar-a-Lago residence in Florida. He theorized then that babies were getting too many shots at once; a few months later, he said that he and his wife, Melania, had slowed down the vaccine schedule for their son Barron, then about 2.
“What we’ve done with Barron, we’ve taken him on a very slow process,” Mr. Trump said at the time. “He gets one shot at a time, then we wait a few months and give him another shot, the old-fashioned way.”
The future president was the host of the NBC reality show “The Apprentice” at the time. The network’s former chairman, Bob Wright, and his wife, Suzanne, grandparents of a child with autism, had founded Autism Speaks two years earlier and asked Mr. Trump to hold a fund-raiser — a concert featuring the singer Lionel Richie — to benefit the group in March 2008.
Although the 1998 medical journal article that kicked off the vaccines-cause-autism speculation had not yet been retracted, Dr. David Mandell, a specialist in autism at the University of Pennsylvania, said there was more than enough scientific evidence at the time to refute the purported vaccine link.
Referring to Andrew Wakefield, the British doctor and lead author of the 1998 study, Dr. Mandell said, “With regard to Wakefield, within four years it was clear that he had faked his data and large, good, epidemiological studies were coming out showing no link.”
Still, many parents were concerned, said Alison Singer, who was then the executive vice president of Autism Speaks. Ms. Singer, who left Autism Speaks in 2009 to start her own organization, the Autism Science Foundation, said the scientific questions around vaccines and autism were settled, and there was no link.
But she remembers the president raising it when he and Mrs. Trump greeted her and the Wrights over brunch at Mar-a-Lago.
“Melania was carrying Barron, he was a baby, and even at that time, Donald Trump did talk about his interest and concerns around vaccines,” she said, adding, “I do believe that he comes to the question of trying to find the cause of autism legitimately.”
Mr. Trump may also have political reasons for wanting to address the autism epidemic. He is well aware that Mr. Kennedy, who has also repeatedly claimed that vaccines are linked to autism, helped get him elected.
“I think this is both personal and political” for Mr. Trump, said Craig Snyder, a Washington, D.C.-based lobbyist who represented Autism Speaks in 2007, and now represents the Autism Science Foundation.
“On the personal side, he’s thought this was a priority issue for a very long time,” Mr. Snyder said. Referring to Mr. Kennedy’s Make America Healthy Again movement, he added: “And on the political side, I think that he believes that MAHA supporters, Kennedy supporters are a really important part of his coalition. They are a significant reason he won the election. So this is under the rubric of fulfilling a campaign promise.”
About one in 31 American 8-year-olds have an autism diagnosis, according to the Centers for Disease Control and Prevention. In 2007, the number was one in 150.
“When I was growing up, autism wasn’t really a factor,” Mr. Trump told The South Florida Sun-Sentinel at the time. “And now all of a sudden, it’s an epidemic. Everybody has their theory, and my theory is the shots. They’re getting these massive injections at one time. I think it’s the vaccinations.”
In the nearly two decades since the fund-raiser, Mr. Trump has continued to express concerns about autism and vaccines. He raised the issue on social media in 2014 and again during a presidential debate in 2015. “I’ve seen it, a beautiful child, went to have the vaccine,” Mr. Trump said. A week later, the child developed a fever and is now autistic, he said.
In 2017, shortly before he was inaugurated, Mr. Trump met at Mar-a-Lago with a group of autism advocates who believe that vaccines are responsible.
Mr. Trump invoked a similar story on Monday. He spoke, as he has in the past, of an unnamed woman who worked for him at the Trump Organization, and who told him she had “lost” her son after he was vaccinated and spiked a high fever.
“I’ve lost him, sir, he’s gone,” Mr. Trump said, recounting what he said were the woman’s words. “And then I saw the boy. It was a whole — it was so tragic to see.”
Many parents of children with autism were thrilled by Mr. Trump’s interest. They have fought for decades for more federal funding for research into the causes of autism and possible treatments. Two mothers of children with autism appeared with Mr. Trump on Monday and expressed their gratitude.
But Ms. Singer saw a great irony in Monday’s announcement.
“All of us who are in the advocacy world and who love people with autism had high hopes that the president and R.F.K. Jr. were serious when they said they wanted to find the causes of autism and that they wanted gold standard autism science,” Ms. Singer said.
“But what we heard today was not gold standard science,” she said. “It wasn’t even science. Instead, President Trump talked about what he thinks and feels without offering any scientific evidence.”