Not Enough Data to Prove or Disprove Autism 'Epidemic'. (Thirty-Two Studies Reviewed)

Article excerpt

SAN DIEGO -- An apparent rise in the prevalence of autism over the past few years has prompted many doctors and parents to conclude that we are seeing an autism epidemic. But, according to Dr. Eric Fombonne, there simply aren't enough data to prove--or disprove--that notion.

A review of 32 surveys conducted in 13 countries between 1966 and 2001, with a median population size of 66,000 and a median age of 8 years, demonstrated a total of 2,380 people with autism, with a median of 50 per survey Dr. Fombonne said at a conference sponsored by the Autism Society of America.

From these surveys, his best conservative estimate of the prevalence of autism was 10 per 10,000, and of all pervasive developmental disorders, 27.5 per 10,000. However, three more recent studies, one of which Dr. Fombonne conducted with his colleagues, put the prevalence of all pervasive developmental disorders at 61.3 per 10,000 to 67.5 per 10,000, and of autism, at 16.8 per 10,000 to as much as 40.5 per 10,000.

The prevalence of all pervasive developmental disorders was "remarkably consistent" in those three reports, said Dr. Fombonne, who heads the McGill University division of child and adolescent psychiatry at Montreal Children's Hospital. The discrepancies among the findings for autism itself "merely reflect the fact that in young children ... where we draw the line between autism and pervasive developmental disorder-NOS [not otherwise specified] is not very clear."

Rather than an "epidemic" of these conditions, it is just as likely that their prevalence has always been higher than previously thought, he told CLINICAL PSYCHIATRY NEWS. …