LEICESTER, England, Jan. 31 (UPI) -- British adults with a severe learning disability have elevated risk of autism and often live in private homes "invisible" in autism estimates, researchers say.
Study author Dr. Terry Brugha of the University of Leicester and colleagues estimated the prevalence of autism spectrum conditions in adults using data from the 2007 Adult Psychiatric Morbidity Survey.
The report involved a survey of adults from learning disability registers in Leicestershire, Lambeth and Sheffield from August 2010 to April 2011.
"We were surprised by how many adults with moderate to profound learning disability had autism because previous estimates pointed to lower rates in this group," Brugha said in a statement. "This group is a small part of the adult population."
The study, published in the Archives of General Psychiatry, found about 60 percent of men with profound learning disabilities and 43 percent of women with profound learning disabilities have autism but have not been included in data previously.
It might seem surprising how many live at home with parents or relatives who provide 24-hour care and which must be a considerable burden, the researchers said.