Johnny L. Matson, PhD, Jonathan Wilkins, Jill C. Fodstad
Objective: While autism spectrum disorders (ASD) constitute a group of similar conditions, considerable heterogeneity in symptoms of these neurodevelopmental disorders have been noted. One of the most important, yet least studied, of these factors is developmental regression.
Methods: One-hundred and twenty-five children were studied and broken down into the following three groups: ASD children with and without substantial regression and typically developing children. In study one, the three groups were compared on global measures of ASD symptomatology, comorbid psychopathology, challenging behaviour and social skills. In study two, the two ASD groups were compared on each individual item from the dependent measures.
Results: Mean age when regression occurred was 27.76 months. The ASD children as a whole differed from the typically developing controls, showing more symptoms of ASD, as would be expected, and poorer social skills, while differences were also noted between the two ASD groups.
Conclusions: It was determined that children with ASD who regress present with a distinct behavioural profile when compared to children with ASD who do not regress, which included greater levels of impairment on global measures of ASD symptomatology, comorbid psychopathology, challenging behaviour and social skills.
It has long been thought (or speculated at least) that children who regress into autism are different than children who show signs of it from birth or simply fail to acquire skills when they should. Yet, there has not been much research into the exact differences between the two groups. This is one of the first studies that I have seen that says that there is a behavioral difference between the groups.
It is my belief that this regressive group is more likely to have a form of autism that is "triggered" by something rather than to have a purely genetic form and should be broken out separately from other forms of autism in research studies. Yet, up until now, I have not seen anybody suggest that it would be possible to separate the two groups. Perhaps it would be possible if regressive autism has slightly different behaviors associated with it.