- Explain to patients who ask that the authors of this study found that, at least in Denmark, diagnoses of autism, autism spectrum disorders, Tourette's syndrome, and hyperkinetic disorder rose significantly in the 1990s, but whether the increases are coincidental or attributable to shared factors is unknown.
- Explain to patients who ask that thimerosal, a mercury-based preservative agent, was removed from all vaccines in Denmark in 1992, indicating that mercury in vaccines could not have accounted for the increases seen.
AARHUS, Denmark, Feb. 5 -- Four common neuropsychiatric disorders of childhood appear on the rise, with Tourette's syndrome, and hyperkinetic disorder joining autism and autism spectrum disorder, researchers here reported.
In a study of records on 670,000 Danish children born in the 1990s, there were statistically significant increases in cumulative incidence across specific birth years for all four conditions, reported Hjördís Ósk Atladóttir, M.B., of the University of Aarhus. and colleagues in the February issue of the Archives of Pediatrics & Adolescent Medicine.
There was no increase in the incidence of obsessive-compulsive disorder over the same period, however, the investigators reported.
"Although the reasons for the observed common pattern of change in reported cumulative incidence in Tourette's syndrome, hyperkinetic disorder and autism spectrum disorder cannot be addressed with these data, it is clear that the number of children with neuropsychiatric disorders and their families in need of support and services has been growing in recent years," the authors wrote.