MONDAY FEBRUARY 26 2001

RATES of autism have risen faster in the past decade than previously thought, but the cause remains a mystery, researchers said yesterday.

A British study to be presented at a conference in April will show a tenfold rise in diagnosis of the condition, which restricts a person’s ability to communicate and make sense of the world.

The figures for 1983 to 1999, compiled by the Autism Research Unit at Sunderland University, are so high that researchers at first thought they were wrong. But they have been repeated by several other teams, including an American study of figures from British GPs, published in the British Medical Journal on Saturday. This showed a sevenfold rise in newly diagnosed autism between 1988 and 1999.

A recent study of children in Cambridgeshire by the Autism Research Centre at Cambridge University suggested that the rate of autism could be one in every 175 primary school children.

Paul Shattock, director of the Autism Research Unit and vice-president of the World Autism Organisation, said there were many possible causes of the rise, from better diagnosis to vaccinations to pollutants in food and water, such as pesticides, hormones, plastics and heavy metals. He refused to rule out the mumps, measles and rubella (MMR) vaccination, which was linked to autism by some researchers but dismissed by the Department of Health as a cause.

The latest study in the BMJ also found no link between autism and the MMR.

Researchers from Boston University School of Medicine said that because MMR rates remained constant while autism was rising sharply, the vaccine could not be the cause of the increase.