*** Data Sadly Missed: Childhood Disintegrative Disorder

My last article looked at the effects of the changes in the DSM one year on, focusing on the deletion of Asperger's syndrome but, of course, there was also another omission that attracted little attention; possibly because Asperger's syndrome took precedence. And yet that omission too is of great importance.

As those who followed the DSM saga will already know Childhood Disintegrative Disorder (CDD) was removed. This condition, originally named 'dementia infantilis', was originally described by Austrian educator Theodore Heller in 1908, some 35 years before Leo Kanner and Hans Asperger identified autism.

Initially Heller described 6 children who, after a period of apparently normal development, gradually lost their previous language and social skills and deteriorated: a regression sometimes so dramatic - and traumatic - that the child concerned was aware of it; some even asking what is happening to them. How incredibly frightening must that be.

Over the years his involvement with and interest in such children continued and later he also proposed that CDD could be identified by the following diagnostic guidelines:

* Onset usually between 3 and 4 years (it occasionally affects children between 2 to 10).

* Progressive intellectual/behavioral regression with marked impairment or loss of speech.

* Associated behavioral symptoms e.g. over-activity or possible hallucinations.

* Such children are often aloof, unable to care for themselves and are prone to epilepsy.

He also noted that some of the children who developed such problems already had a degree of developmental delay prior to the onset of the disorder even though such delays were not always obvious in younger children.

Thought to be relatively rare, Heller's syndrome was only officially classified as a developmental disorder in the diagnostic criteria in 1994; where it was characterized by:

A) Apparently normal development for at least the first 2 years after birth as manifested by the presence of age-appropriate verbal and nonverbal communication, social relationships, play, and adaptive behavior.

B) Clinically significant loss of previously acquired skills (before age 10 years) in at least two of the following areas:

1. Expressive or receptive language.
2. Social skills or adaptive behavior.
3. Bowel or bladder control.
4. Play.
5. Motor skills.

C) Abnormalities of functioning in at least two of the following areas:

1. Qualitative impairment in social interaction (e.g. impairment in nonverbal behaviors, failure to develop peer relationships, lack of social or emotional reciprocity).
2. Qualitative impairments in communication (e.g. delay or lack of spoken language, inability to initiate or sustain a conversation, stereotyped and repetitive use of language, lack of varied make-believe play).
3. Restricted, repetitive, and stereotyped patterns of behavior, interests, and activities, including motor stereotypies and mannerisms.

D)The disturbance is not better accounted for by another specific Pervasive Developmental Disorder or by Schizophrenia.

The Neurodevelopmental Disorders Workgroup involved in reassessing and revising the DSM criteria were concerned about using the term CDD for three main reasons. Firstly they believed that it was little used by diagnosticians - which obviously made any systematic evaluation difficult. Secondly, after reviewing much of the literature on the subject, they found that it had important differences from other types of autism, from the acuity and severity of regression, to co-occurring physical symptoms, such as loss of bowel and bladder control. That led them to suggest that it might have a neurological basis.

Thirdly, while Heller put the age of onset at three and the DSM-IV lowered it to the age of two the Workgroup noted that developmental regression is now a continuous variable, with a wide range in the timing and nature of the loss of skills, as well as the developmental milestones that are reached prior to regression. Hardly surprising then that the diagnosis was rare, for the criteria would automatically have excluded any children under two from receiving it.

But whether that makes it right to exclude it is a moot point.

Clearly, as the Workgroup identified, the onset of developmental regression has changed considerably so that nowadays it can, and often does, occur at a much earlier age that it did when Heller revised his criteria later on. However all the evidence suggests that it is no longer a rare condition/disorder.

Leaving the issue of age aside it seems, unfortunately, that there are many children who would fit at least some of Heller's criteria; having had a period of 'apparently normal development' prior to regressing and losing some of the skills they had previously attained: even if, as Heller suggested, some (but by no means all) had a degree of developmental delay prior to the onset of the disorder.

And yes some of those children have physical symptoms too, such as loss of bowel and bladder control - although to confuse the picture, many children who regress have been found to have various identifiable bowel and stomach disorders.

Perhaps it all depends on how you view diagnosis? Clearly accurate diagnosis is a vital tool in determining the correct treatment/s. But perhaps it could - and should - aim to be more than that? Surely it would be of even more value if it provided clear information for research too.

In my opinion the only way to do that is to include the 'rarer' categories within the diagnostic criteria for ASD too - giving clear guidelines to aid the diagnosticians. Thus the criteria for CDD would certainly have needed amendment re the age of onset as well as additions in relation to prior developmental delay and bowel/bladder control. But what an opportunity might be gained if researchers could identify different groups of children prior to beginning their research: differentiating between children who regressed after some developmental delay and those who development was 'normal'; or those who have a loss of bowel control and those who have a bowel disease for instance.

Too late for the DSM. Is it too late for the World Health Organization's forthcoming revision of ICD-11 Classification of Mental and Behavioral Disorder due out in 2017? It seems as if it might for CDD already seems to have disappeared from the preliminary revision of the ICD-11. Am I the only one to think that looks set to be another missed opportunity?