Regression of language and non-language skills in pervasive developmental disorders.
Roughly one in five kids with PDD lose skills, most often those with autism who talked early and flap or line things up a lot.
01Research in Context
What this study did
The team looked back at clinic charts for children with pervasive developmental disorders. They asked two questions: how many kids lost skills, and what made those kids different.
Parents had already told clinicians if the child ever lost words, play, or self-care. The study pulled those notes into one big picture.
What they found
About one in five children had lost skills. Most of them had autism, not another PDD label.
Kids who later lost language had actually started talking a little earlier. They also showed more hand-flapping, lining up toys, or other repeated actions.
How this fits with other research
Siperstein et al. (2004) saw the same parent reports first. They warned that many "loss" stories look more like slow gains that stopped. The new numbers match, but add clearer check-box signs.
Mount et al. (2011) counted 24 % regression in a bigger autism-only sample. The close match gives you confidence that 22–24 % is the real range.
Pearson et al. (2018) later watched babies month-by-month. Prospective diaries show smaller, slower dips than the dramatic loss parents recall years later. The papers do not fight; they just show two lenses—parent memory versus live tracking.
Warnes et al. (2005) found that regression history does not predict later IQ. Bhaumik et al. (2009) add that it does predict more repetitive behaviors. Together they tell you: note the regression, but keep teaching the child in front of you.
Why it matters
When intake forms say "lost words," you now know there is a one-in-five chance the child will also show lots of stereotypy. Plan for extra visual schedules and sensory breaks. Do not bank on early talking as a shield; watch the skills that are here today and teach from there.
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02At a glance
03Original abstract
BACKGROUND: As part of the pervasive developmental disorders (PDD), there is a subgroup of individuals reported to have a different onset of symptom appearance consisting of an apparently normal early development, followed by a loss of verbal and/or non-verbal skills prior to 2 years of age. This study aims at comparing the symptomatology of children who displayed a regression and often an associated intellectual disability through investigation of two types of loss, namely language and other skill regression. METHODS: This study examined the occurrence of regression in 135 children with PDD, mean age 6.3 years. The sample was composed of 80 (59.4%) children diagnosed with autism, 44 (32.6%) with pervasive developmental disorder-not otherwise specified (PDD-NOS) and 11 (8%) with Asperger syndrome. The Autism Diagnostic Interview Revised (ADI-R) was used to evaluate the type of loss and to characterise associated factors including birth rank, gender and thimerosal exposure through vaccination. RESULTS: A total of 30 (22%) subjects regressed: nine (30%) underwent language regression alone, 17 (57%) lost a skill other than language and four (13%) lost both language and another skill. Significantly higher levels of regression were found in autism (30%) compared with PDD-NOS (14%) and Asperger syndrome (0%). Children who regressed in language skills spoke at a significantly earlier age ( = 12 months) than those who did not regress in this domain ( = 26 months). Parents and interviewers consistently reported developmental abnormalities prior to the loss. ADI-R domain mean scores indicated a more severe autistic symptomatology profile in children who regressed compared with those who did not, especially in the repetitive behaviour domain. Regression was not associated to thimerosal exposure, indirectly estimated by year of birth. CONCLUSIONS: A loss of skill, present in one out of five children with PDD, is associated with a slightly more severe symptomatology as measured by the ADI-R, particularly in the repetitive behaviours domain. Furthermore, although abnormalities are often noticed by the caregivers at the time of regression, the ADI-R reveals that other atypical behaviours were in fact present prior to the onset of regression in most cases. None of the secondary factors investigated were associated with regression. In children unexposed to thimerosal-containing vaccines, the rate of regression was similar to that reported in studies of samples exposed to thimerosal, suggesting that thimerosal has no specific association with regressive autism.
Journal of intellectual disability research : JIDR, 2009 · doi:10.1111/j.1365-2788.2008.01134.x