A new Government study of US children diagnosed with ASD suggests that as many as 13% of them lose the diagnosis and that almost three-quarters of those do so because of ‘new information’
The study carried out by researchers at the US Centers for Disease Control and Prevention, the University of Washington, the National Institutes of Health, and the Health Resources and Services Administration, supports several previous studies suggesting overdiagnosis of children with ASD.
The new study also explores in greater detail which previously diagnosed children are more likely to lose their ASD diagnosis and why. It uses the largest national sample to date to examine retrospective parental reports about the characteristics of their children around the time of the initial ASD diagnosis, how the initial diagnosis of ASD was obtained, and who provided it, to determine whether these can predict future loss of ASD diagnosis.
Previous studies suggest that children with higher IQs (>70), early communication and language abilities, and those who have received earlier and more extensive interventions are more likely to lose their ASD diagnosis. Others suggest that the ASD subtype diagnosis may be a determining factor, with children diagnosed with pervasive developmental disorder—not otherwise specified (PDD-NOS) and Asperger’s disorder being more likely to move off the spectrum than children diagnosed with autistic disorder.
Of the children ever diagnosed with ASD, 13.1% were estimated to have lost the diagnosis. The key differences between those previously diagnosed and those currently diagnosed were that the latter were more likely to currently possess essential daily living skills such as using the bathroom by themselves, feeding themselves, and asking for things or information when needed.
Children currently diagnosed with ASD also had a higher mean factor score on the Children’s Social Behavior Questionnaire (CSBQ), indicating a higher level of autism symptomatology than those previously diagnosed.
The most common perceived reason for a lost diagnosis was a change due to new information (73.5%). Approximately one in four children who lost their ASD diagnosis were said to have never had the condition but to have received the diagnosis due to a need for a diagnosis to receive services (24.2%). The next most common reason for a lost diagnosis was treatment or maturation (21.0%). A small proportion of previously diagnosed children had parents who simply believed that their child’s ASD diagnosis had been incorrect despite the doctor’s judgement (1.9%).
The researchers suggest overdiagnosis could be the result of difficulty distinguishing children with ASD from children who possess language delays or global developmental delays and because of variability in the quality of screening and evaluation practices. Many of the children who lost their ASD diagnosis were given a new diagnosis of ADHD, which the study says may be the result of overlapping symptoms. Over-diagnosis may also be because of the greater availability of resources for treatment of children with an ASD diagnosis or because children are given the diagnosis as a precautionary measure pending a more thorough assessment.
Significantly the study also found that, ‘Only 21% of children with a lost diagnosis (or less than 3% of all school-aged Children with Special Health Care Needs ever diagnosed with ASD) were said to have lost it due to treatment or maturity. The true rate of recovery may be even smaller if some of these children were incorrectly thought by their parents or doctors to have lost their ASD because they now have well-developed coping skills and other strengths.’