Regression and word loss in autistic spectrum disorders

Lord C, Shulman C, DiLavore P.
University of Michigan, Ann Arbor, Michigan; Hebrew University of Jerusalem, Israel; University of North Carolina–Chapel Hill, North Carolina

Abstract: J Child Psychol Psychiatry. 2004 Jul;45(5):936-55

Findings

For many years, doctors and researchers have described parent reports of an unusual phenomenon in children with Autistic Spectrum Disorders (ASD)—during the second year of life, the child gains and then loses their ability to communicate. While parent reports and some videotapes can be helpful in describing this phenomenon, it is seldom comprehensive, and researchers do not fully understand this problem. To study this in a controlled setting, Dr. Lord and her colleagues examined several groups of children referred to their clinics by a series of diagnostic and word tests to assess the child’s patterns of word use. As part of a longitudinal study, 21 children with developmental delay, 68 children with autism, 28 children with pervasive developmental disorders (PDD-NOS), 14 children with possible autism, and 33 typically developing controls were given a standardized test battery at entry into the study and at ages 4 to 5. As part of these assessments mothers were asked specific questions about the onset of difficulties. There was a loss of less specific, non-word vocalizations in all children with cognitive delay, with or without autism. However, the 19 children who—were described by their parents as having gained and then lost spontaneous, meaningful words at age 2, were all from the autism or PDD group (14 in the autism group and 5 in the PDD-NOS group) Thus, about 25% of children with ASD were described by parents as having gained and used words meaningfully but losing this skill in the second year of life. The tests showed that children who gained a small number of words they used consistently and meaningfully followed by loss of all words, was unique to those diagnosed with ASD at 5 years of age. Besides patterns of word loss, there were few cognitive differences between children with ASD with and without word loss.

Conclusions

Dr. Lord and her colleagues conclude that word loss is a phenomenon that can be reliably identified in early childhood that is unique—but not universal—to children with ASD, and is an unusual pattern in early development of autistic children. This phenomenon of words gained and then lost early in life may be a useful signal for parents, alerting them to the possibility of autism in the child.
The researchers do not know exactly what causes these changes. Future research will need to address a number of questions, including why certain children with ASD are able to use words spontaneously and meaningfully early in development, why they do not progress, why these initial skills do not persist and are lost, and why words are eventually regained in some children.