State Shows Decline in Autism Diagnosis Rates, Possible Sign of Nationwide Drop

The number of newly diagnosed autism cases reported in California has evened out and might have begun to decline, according to data from the Department of Developmental Services, the Los Angeles Times reports. The data indicate that the rate of increase in newly diagnosed autism cases peaked in 2002 and since has decreased slightly.

According to the data, 1,470 new cases were reported in the first half of 2005, compared with 1,518 in the same period in 2004. For all of 2004, 3,074 new autism cases were reported, compared with 3,125 in 2003 and 3,259 in 2002. The data do not include children under the age of three.

DDS officials said about 90% of all autistic children are entered into the state's tracking system before the age of six.

The Times reports that California has the most accurate reporting system for autism in the nation and as a result the state is "generally considered a bellwether" for the rest of the U.S.

Rick Rollens, an advocate for autism research, said the phasing out of mercury from pediatric vaccines in the 1990s might have contributed to the decrease, but experts said the reason for the decline is unclear (Maugh, Los Angeles Times, 6/13).