Regression and word loss in autistic spectrum disorders

Lord C, Shulman C, DiLavore P

Journal of Child Psychology and Psychiatry 2004; 45(5): 936-955

Bottom Line

Does the loss of words acquired during the first two years signal later development of an autistic spectrum disorder?

  • Some parents have reported that their children with autism stopped talking during their first two years.
  • This study showed that there is a minority of children who lose their ability to talk and to use other social behaviours around the age of 1 or 2.
  • Loss of words that have been used on a daily basis and to mean the same thing is a red flag that there may be serious developmental problems that require investigation.

Question: Does the loss of words acquired during the first two years signal later development of an autistic spectrum disorder?

Background: Parents and clinicians have reported that there is a group of children with autistic spectrum disorders who lose the use of language after having acquired meaningful words during their first two years. Parents have dated the onset of their children’s condition to this apparent sudden regression. Researchers have disputed the suddenness of this process, but it is apparent that some children do lose the ability to communicate. This study looked at this phenomenon in children who were part of a longitudinal study.

Design: Time series (as part of a longitudinal study).

Setting: Four TEACCH centres in North Carolina.

Participants: The participants consisted of three groups of children:

  1. 110 children referred to a clinical centre with symptoms suggestive of autism or other communication disorders who were seen at 2, 3, and 4 or 5 years of age;
  2. 21 children with developmental delays who were tested at 2 and then at 4 or 5 years of age; and
  3. 33 typically developing children aged 20 to 32 months who were tested only once at entry to the study.

Assessment of prognostic factors: Diagnosis of an autistic spectrum disorder (ASD) and loss of previously acquired meaningful language.

Main Outcome Measures: Communication loss as defined as: 1) loss of words, 2) fluctuating word loss, 3) loss of vocalization, and 4) no word loss.

Main Results: In children diagnosed with autism, a single period of word loss or a history of early repeated word losses was specific to children with ASDs. Most children who experienced word loss reached a plateau of word acquisition and use in their first and second years and then began to lose these skills. The losses were frequently associated with social interaction and communication abnormalities.

Conclusions: This study does provide evidence that there is a minority of children with ASDs whose early development is characterized by word loss and social skills loss. It is often thought that development prior to regression is perfectly normal, but it is likely that there were subtle signs that the child’s earlier development was not typical. In fact, in this study it was noted that the word loss was preceded by a leveling off of vocabulary growth and the use of speech. The pattern noted in this study, in which the child has acquired spontaneously, and consistently used, a small number of words meaningfully and then loses these words, is not seen in other developmental disorders, but also is not seen in all children with an ASD. The authors indicate that word loss may be a red flag that should initiate investigation and interventions. It is important to note that this pattern of word loss can appear regardless of the severity of the child’s condition, and it does not indicate a poor prognosis.