Autism prodrome 5 of 89
develop the disease also show the prodrome prior to appearance of the full blown
clinical picture of an ASD. As ASDs include a group of behavioral syndromes that
are most likely common to more than one etiological mechanism (Geschwind, 2008;
Geschwind & Levitt, 2007; Levitt & Campbell, 2009); it is probably very difficult, if
not impossible, to conceive of a specific and universal prodrome of ASDs. Rather,
the risk factors and prodromes may be as diverse as the many etiologies and
developmental trajectories underlying ASDs.
Several sources of data are available to researchers and clinicians who are
trying to delineate the early risk markers and prodrome/s of ASDs. First, many single
and multiple case studies regarding children with autism and other related syndromes
are available to the interested reader. Many parents have written books about their
experience raising their children with autism; including some with very rich case
materials (e.g., Park, 1967). In addition to case reports, the literature on early markers
for ASD includes both retrospective and prospective studies regarding the early
development of children who later on are diagnosed with ASD. Retrospective
information is mostly collected via parental reports using various questionnaires and
interviews and/or home videos of the children, taken prior to the child receiving the
diagnosis. Although retrospectively collected clinical information and parental
accounts are important and provide tantalizing glimpses into what might be the
earliest manifestations of autism; these accounts may be subjected to reporting biases
of several kinds that leave open the accuracy of the early characteristics that are
recalled many years later. In addition to retrospective studies and reports, currently,
many prospective studies are carried out. These studies involve samples of young
children from the general population who have some initial risk marker such as, for
example, being identified as ‘at risk’ by failing a screening questionnaire and/or being