Autism and Language Regression

So what is the deal with language regression? How common is it really? It is not uncommon for me to hear parents talking about their child's sudden loss of language. What could be the cause?

Regression in ASD is not an uncommon occurrence by far. The major trouble with regression is not the fact that it occurs, but the fact that researchers have a loose definition of what that means. How a researcher defines regression greatly impacts the results of their findings, which will help explain the differences in the statistics you will see.

In 2004 the University of Michigan conducted a large study encompassing 1,592 children with ASD from 13 treatment centers across the United States. The researchers conducted intensive individual studies of 351 cases which represented 163 cases of regression and 188 without regression. At the time this effort was the largest known study of its kind. The researchers found that approximately 77% of children experiencing language loss also lost forms of non-verbal communication. In their body of subjects the mean age of loss was approximately 19 months old. Most parents saw an almost immediate loss, with no warning signs of regression. This next part is very important: The researchers found no evidence that regression in ASD is associated with the reception of the MMR vaccine. The MMR vaccine is typically given around 18 months of age. The mean loss of language was approximately 19 months. For medical science to recognize something like a vaccine causing regression the time gap wouldn't be so large. The next is it wouldn't differ so much among cases. Every child is different and their regression is varies so much per individual that medical science cannot "blame" the vaccine for causing it. 

In 2012 SFARI published an article about regression in Autism, based on an analysis published by the Journal of Autism and Developmental Disorders. Researchers conducting this analysis found that approximately one in three children with Autism abruptly lose language, social, or developmental skills in their second year of life. They found the information from an in depth study of 85 different studies from 1980-2010 all focusing on regression and including approximately 30,000 individuals with ASD. In this study the estimated regression rate varied from approximately 13% to 50% of Autism cases, due to the varying definitions of regression. In light of this researchers divided the studies nto four types: 1- language regression, 2- language and social regression, 3- mixed regression, and 4- unspecified regression. They found that the overall prevalence of regression is approximately 32% and language regression occurred in approximately 25% of cases. Unspecified regression occurred at a rate of about 39% and had the broadest definition of regression. Meaning it could encompass any act of regression on the part of an individual, regardless of the skill. These researcher's had a mean regression age, based on 24 studies, of approximately 21 months of age. 

In 2014 Autism Speaks posted an article about preliminary research conducted by the IAN Network. The IAN Network defined regression as a "loss of previously acquired skills".The lead researcher, Sally Rogers, from the U.C. Davis M.I.N.D. Institute also described the three onset patterns she used: 1- No period of typical development (ASD from birth), 2- Developmental plateau (Milestones are reached and then sudden stop), 3- Regression. IAN collected their information via Internet questionnaires of parents registered in their network. For instance, I am part of the IAN Network, its free to join and you simply chose the studies you wish to participate in. Lets discuss findings: IAN discovered that the majority of subjects lost skills between 13-18 months of age. 

IAN Age of Skill Loss Chart per Diagnosis

IAN also compiled a graph chart of the percentage of children with skill loss between 0-36 months of age, by diagnosis. They found from their research that 49% with Autism experienced skill loss, 35% with PDD-NOS experienced skill loss, 42% with ASD experienced skill loss, and, surprisingly, 15% with Asperger's Syndrome experienced skill loss. They also ranked the severity of regression in the chart below:

IAN Chart on Severity of Regression per Diagnosis

IAN researchers then looked into the specific skills lost. They broke them into four groups: 1- Speech, 2- Social, 3- Motor, and 4- Daily Living. They found that in cases with Autism diagnosis 77% lost speech, 18% lost social skills, 3% lost motor skills, and 2% lost daily living skills. In cases of PDD-NOS 81% lost speech, 14% lost social skills, 2% lost motor skills, and 3% lost daily living skills. Finally in Asperger's cases 44% lost speech skills, 42% lost social skills, 5% lost motor skills, and 9% lost daily living skills. IAN also researched developmental plateaus in Autism, but that will be covered in a different post.

What do all those numbers mean? IAN reports of their research families, those who participated, that 39% of children with varying types of ASD and 49% of children with Autism suffer a skill loss by the age of 3 years. Speech and language was reported as the area most affected of all four areas IAN investigated. 

So what causes regression? Researchers are not sure what causes regression. There is a link between epilepsy and regression. Interestingly enough the SFARI article states 1 in 3 individuals with Autism show regression in some category of skill, 1 in 3 is also how many children with Autism suffer from seizures. The link has yet to be proven and some researchers reject the idea that epilepsy causes regression. In 2007 the Developmental Medicine and Child Neurology journal published an article: Clinical Characteristics of Language Regression in Children. Researchers in this study of 196 children with language regression were evaluated by a neurologist. These children presented the following triggers that may have caused or contributed to regression: 74% of these children presented a trigger point causing their regression. Of those trigger points: 7% were seizures, 46% due to medical or surgical illness, 2% physical trauma, and 30% emotional trauma. Please read the article for lots more great information about the possible causes or contributing factors to regression.

So what are the warning signs of regression in Autism? A lot of parents report an immediate loss, an overnight phenomena, of some form of skills their children earned in the past. Parents usually see this loss between 12-24 months of age. If you notice your loved one becoming socially or emotionally isolated or a sudden loss of language, please immediately contact your therapy team. Intensive treatment needs to begin immediately and can stop or hopefully reverse the regression. To read more about regression and what you can do, or Autism, please see this article from autism.net. 

For more information about the possible link between epilepsy and Autism please see this article by the Epilepsy Currents and read our blog post: Autism and Epilepsy.

If you would like to participate in future IAN Network studies, please sign up through their website, it is free to join. 

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