Thimerosal and Autism

The results of a study by researchers at the Department of Public Health in California do not support the hypothesis that autism is caused by thimerosal, a preservative containing ethylmercury that was once used in childhood vaccines. The researchers found that the incidence of autism rose steadily in California from 1995 to 2007, even though thimerosal was removed from most childhood vaccines in 2001. If thimerosal were responsible for causing autism there should have been a sharp decline in new cases of autism after 2004. The new findings and a commentary about them are published in The Archives of General Psychiatry.

It is doubtful that the study will do much to reassure parents, however, some of whom continue to believe passionately that their child's autism was a direct consequence of childhood vaccinations despite research findings to the contrary.