I was dismayed to read in the August 20 issue that "the case is
becoming stronger that perinatal complications play a causative role in
autism." The authors of the study did not state that perinatal
complications are a causative factor in autism. They pointed out that there
was an association between the occurrence of perinatal complications and the
eventual diagnosis of autism in the involved children. The finding of an
association between perinatal complications and autism has, in fact, led some
to suspect that the ultimate cause of autism is also the cause of the
perinatal complications, thus giving us another piece of information to use to
find the actual cause.
There is a crucial difference between cause and association. The confusion
of these two frequently leads to misinformation and misunderstanding by the
public of scientific evidence.