What Is Childhood Disintegrative Disorder
Childhood Disintegrative Disorder (CDD), also called Heller syndrome and degenerative psychosis, is a rare condition characterized by late-onset (>3 years of age) delays in language development, social function, and motor skills.
Childhood disintegrative disorder was first described by an Austrian educator, Thomas Heller, in 1908. Childhood disintegrative disorder is defined as a complex disorder that affects many different areas of child development. It’s grouped with Pervasive Developmental Disorders (PDDs) and is related to the better-known and more common disorder, autism.
Therefore, it’s a condition that’s characterized by a clear regression of developmental functioning and behavior. This occurs after a period of apparently normal development for at least two years.
Neuropathological and other conditions are sometimes associated with this disorder, but the truth is that it’s not as typical as is believed.
Childhood dementia
It was in 1908, that is, 35 years before autism was defined as such, when Theodor Heller identified a group of children who showed typical development up to 3 or 4 years of age. This development was followed by a severe and sudden regression of cognition and speech.
This was called childhood dementia, and it’s often associated with mood dysregulation, including anger and anxiety. Since then, a debate has surrounded the validity of this rare diagnosis: It has undergone changes in nomenclature that reflect fluctuating opinions about its nosology.
From “childhood dementia” to “childhood disintegrative disorder”, differentiated from ASD
Childhood disintegrative disorder is characterized by a regression in developmental and adaptive skills. Added to this is the appearance of autistic symptoms in a child who was apparently typical during at least the first 2 years of life.
The differences between childhood disintegrative disorder and ASD
Literature reviews have reached different conclusions about the validity of this disorder as a separate entity from autism spectrum disorder (ASD). The few distinguishing characteristics of this disorder with respect to ASD include some such as its rarity, the general presence of regression, and late age, as well as the suddenness of onset in relation to ASD.
Some research considers this disorder to be part of a continuum within ASD. Phenotypic similarities between the two disorders include both fundamental deficits in social communication and concomitant intellectual disability and epilepsy.
Childhood disintegrative disorder has been associated with impairment in a broader set of domains than ASD, such as coping skills (such as self-help or toileting, for example) and emotional and behavioral regulation.
Reports on ASD have described patterns initially exhibiting apparently typical social-communicative development followed by gradual regression during the first 2 years of life.
A second pattern, present in more than half of people with ASD, involves deficits in the development of social communication before the onset of regression. In contrast, case reports of childhood disintegrative disorder describe at least 2 years of apparently typical development with all developmental milestones achieved.
Regression in childhood disintegrative disorder has been described as rapid and dramatic, in contrast to the more gradual regression process in ASD.
Diagnosis
The essential feature of childhood disintegrative disorder is a distinct regression of developmental and behavioral functioning after a period of apparently normal development. This has to occur for at least 2 years. Specifically, it occurs in reference to age-appropriate communication, relationships, interactions, and behavioral criteria.
The DSM-IV-TR (Diagnostic and Statistical Manual of Mental Disorders, 4th Edition) indicates that the degeneration of mental and physical functioning must include clinically significant impairment of previously acquired abilities.
In most cases, especially when the child’s developmental milestones have been age-appropriate (ie, speaking in complete sentences, going to the bathroom alone…), a dramatic loss of skills (becoming mute, developing incontinence…) at the onset of the degenerative disorder is quite evident. Therefore, this loss poses great concern for caregivers.
At the same time, in addition to the loss of functioning, the child must also begin to exhibit at least two of the behavioral impairments commonly seen in autism. These include:
- Deficits in social interaction
- Communication deficiencies
- Stereotyped behavior patterns
Once the symptoms are fully established, childhood disintegrative disorder resembles autism so much that if the period of normal development isn’t clearly documented, the two disorders are indistinguishable.
How is the diagnosis carried out?
Childhood disintegrative disorder is most often diagnosed when the parents of the affected child consult the pediatrician about the loss of previously acquired skills.
First, the doctor will do a medical exam to rule out any organic cause for the condition. After medical examinations and tests, the child will be referred to a psychiatrist who will then make a differential diagnosis of the disorder.
To be diagnosed as having childhood disintegrative disorder, a child must show loss or regression in at least two of the areas listed below. In addition, they must have undergone apparently normal development for at least the first 2 years after birth.
To diagnose a child with this disorder, a regression must exist in several areas
Usually, regression occurs in more than two areas. These are the following:
- Motor skills
- Play with peers
- Receptive language skills (language comprehension)
- Expressive language skills (spoken language)
- Bowel or bladder control, if previously established
The child must also have abnormal functioning in at least two of the following areas:
- Impaired nonverbal behaviors, the inability to develop relationships with peers without social and emotional reciprocity
- The ability to initiate and maintain conversations with other people
- Restricted, repetitive, and stereotyped behavior, such as bobbing the head up and down or other repetitive movements.
These changes mustn’t be caused by a general medical condition or other diagnosed mental disorder.
Causes
At the moment, the cause of this disorder is unknown. Research results suggest that it may arise in the neurobiology of the brain.
Approximately half of the children diagnosed with this disorder have an abnormal electroencephalogram (EEG). EEGs measure electrical activity in the brain generated by nerve transmission.
Furthermore, this disorder has also been seen to be associated with seizures, another indication that the neurobiology of the brain may be involved in the development of childhood disintegrative disorder.
The prevalence of childhood disintegrative disorder
Childhood disintegrative disorder appears to be a rare disorder, with a prevalence of between 1 and 2 per 100,000 inhabitants. However, due to the difficulty in properly identifying this disorder apart from autism, the prevalence rates aren’t entirely clear.
As far as gender is concerned, it’s estimated that the ratio of boys to girls is 8 boys for every girl.
Etiology
Although many researchers maintain that the progressive impairment of functioning in childhood disintegrative disorder is a strong indication of an underlying general medical condition or genetic condition, no other diagnosable disorder has been found to explain the impairment.
This has led to persistent disagreement over the years regarding the presence or absence of neurological abnormalities in people diagnosed with this disorder.
Originally, it was thought that the symptoms of childhood disintegrative disorder occurred in the absence of detectable neurological abnormalities and dysfunction. However, recent research has indicated that there’s a higher frequency of abnormal electroencephalography (EEG) readings and seizure disorders in people diagnosed with this disorder.
In any case, these abnormalities don’t appear to contribute to the onset of childhood disintegrative disorder.
On the other hand, childhood disintegrative disorder has also been associated with various medical conditions, including the following:
- Neurolipidosis
- Cerebral lipidosis
- Schilder’s disease
- Metachromatic leukodystrophy
- Subacute sclerosing panencephalitis
The disorder definitely co-occurs with autism in the same family, however, its exact cause has yet to be determined. At the moment, research seems to be based on the patterns of appearance and the abnormalities in the behavior of those affected to carry out a diagnosis.
Treatment
Treatment for childhood disintegrative disorder is very similar to treatment for autism. The emphasis falls on early educational interventions and intensity.
Most treatments are behaviorally focused and highly structured. Parent education is also emphasized in the overall treatment plan.
On the other hand, there are other treatments that can be used according to the needs of each child. These are speech and language therapy, occupational therapy, social skills development, and sensory integration therapy.
Childhood disintegrative disorder: An under-researched disorder
Childhood disintegrative disorder was the first diagnostic concept to be described that explained severe and pervasive developmental disorders in children. However, it remains the least understood of the pervasive developmental disorders.
The lack of knowledge about this disorder could be due to a number of factors. These include its rarity, the likelihood that the disorder has simply been underdiagnosed, the difficulty in correctly identifying it, and the strong overlap of the disorder’s symptoms with those of autism.
Furthermore, as with most psychiatric and developmental disorders, there are no definitive diagnostic tests or biomarkers currently available that will unequivocally confirm or rule out this disorder.
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Mehra, C., Sil, A., Hedderly, T., Kyriakopoulos, M., Lim, M., Turnbull, J., … & Absoud, M. (2019). Childhood disintegrative disorder and autism spectrum disorder: a systematic review. Developmental Medicine & Child Neurology, 61(5), 523-534.
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Homan, K. J., Mellon, M. W., Houlihan, D., & Katusic, M. Z. (2011). Brief report: childhood disintegrative disorder: a brief examination of eight case studies. Journal of autism and developmental disorders, 41(4), 497-504.
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Charan, S. H. (2012). Childhood disintegrative disorder. Journal of pediatric neurosciences, 7(1), 55