Alan Zarembo concludes his Los Angeles Times series by looking at undiagnosed autism among adults. The article starts by describing the case of Ben Perrick, identified in David S. Mandell's study of a hospital in Pennsylvania.
The researchers found 13 other patients with unrecognized autism in the Norristown hospital — about 10% of the residents they evaluated. It was a sign of how medical standards and social attitudes toward the disorder have shifted.
Over the last two decades, estimates of the autism rate in U.S. children have climbed twentyfold. Many scientists believe the increase has been driven largely by an expanded definition of the disorder and more vigorous efforts to identify it.
What happened to all the people who never got diagnosed? Where are they?
Like Perrick, who died in 2009, some spent their lives in institutions. Mental hospitals have largely been emptied over the last four decades, but the remaining population probably includes about 5,000 people with undiagnosed autism, said David Mandell, a psychiatric epidemiologist who led the Norristown study.
Many more are thought to be in prisons, homeless shelters and wherever else social misfits are clustered.
But evidence suggests the vast majority are not segregated from society — they are hiding in plain sight. Most will probably never be identified, but a picture of their lives is starting to emerge from those who have been.
They live in households, sometimes alone, sometimes with the support of their parents, sometimes even with spouses. Many were bullied as children and still struggle to connect with others. Some managed to find jobs that fit their strengths and partners who understand them.
If modern estimates of autism rates apply to past generations, about 2 million U.S. adults have various forms of it — and society has long absorbed the emotional and financial toll, mostly without realizing it.
The only study to look for autistic adults in a national population was conducted in Britain and published in 2009. Investigators interviewed 7,461 adults selected as a representative sample of the country and conducted 618 intensive evaluations.
The conclusion: 1% of people living in British households had some form of autism, roughly the same rate that the U.S. Centers for Disease Control and Prevention estimates for children in America today.
The British study found it didn't matter whether the adults were in their 20s or their 80s. The rate of autism was the same for both groups.
"That would seem to imply the incidence has not changed very much,” said Dr. Terry Brugha, a professor of psychiatry at the University of Leicester who led the study. He added that the findings were not conclusive and more research is needed