Childhood disintegrative disorder (CDD), also known as Heller syndrome and disintegrative psychosis, is a rare condition characterized by a late onset of developmental delaysâÂÂor severe and sudden reversalsâÂÂin language (receptive and expressive), social engagement, bowel and bladder, play and motor skills. Researchers have not been successful in finding a cause for this disorder. CDD has some similarities to autism and is sometimes considered a low-functioning form of it. In May 2013, CDD was one of several subtypes of pervasive developmental disorder (PDD)âÂÂincluding Asperger's syndrome, classic autism, and pervasive developmental disorder not otherwise specifiedâÂÂthat was subsumed into a single diagnostic term called "autism spectrum disorder" in the DSM-5 manual.
CDD was originally described by Austrian educator Theodor Heller (1869âÂÂ1938) in 1908, 35 years before Leo Kanner and Hans Asperger described autism. Heller had previously used the name dementia infantilis for this disorder.
An apparent period of fairly normal development is often noted before regressions in skills occurs. The age at which this regression can occur varies, but regression after three years of normal development is typical. The regression, known as a prodrome, can be so dramatic that the child may be aware of it, and may in its beginning even ask, vocally, what is happening to them. Some children describe or appear to be reacting to hallucinations, but the most obvious symptom is that skills apparently attained are lost. Many children are already somewhat delayed when the disorder becomes apparent, but these delays are not always obvious in young children. Many writers have described the condition's impact as devastating, affecting both the family and the individual's future. As is the case with all PDD categories, there is considerable controversy about the right treatment for CDD.
CDD is a very rare condition, with only 1.7 cases per 100,000.
A child affected with childhood disintegrative disorder shows normal development initially. Up until at least three years old, the child has developed normally in the areas of language skills, social skills, comprehension skills, and has maintained those skills for about two years. However, between the ages of three and ten, these skills acquired are lost almost completely in at least two of the following six functional areas:
Lack of normal function or impairment also occurs in at least two of the following three areas:
Most children with CDD regress to severe intellectual disability.
All of the causes of childhood disintegrative disorder are still unknown. Sometimes CDD surfaces abruptly within days or weeks, while in other cases it develops over a longer period of time. A Mayo Clinic report indicates: "Comprehensive medical and neurological examinations in children diagnosed with childhood disintegrative disorder seldom uncover an underlying medical or neurological cause. Although the occurrence of epilepsy is higher in children with childhood disintegrative disorder, experts don't know whether epilepsy plays a role in causing the disorder."
CDD, especially in cases of later age of onset, has also been associated with certain other conditions, particularly the following:
Loss of language and skills related to social interaction and self-care are serious. The affected children face ongoing disabilities in certain areas and require long-term care. Treatment of CDD involves both behavior therapy, environmental therapy and medications.