Atypical autism: what is it and what subgroups of this disorder exist?
Diagnostic classifications categorize autistic spectrum disorders in different ways. Thus, the DSM-5 eliminates the distinction between Kanner's or classic autism, Asperger's syndrome, Rett syndrome and the infantile disintegrative disorder present in the fourth edition of the manual, while ICD-10 includes the diagnosis of "Atypical Autism" .
In this article we will explain the basic characteristics of this variant of autistic disorder. The diagnostic category is used mainly to describe forms of autism in which the symptoms are mild, uncommon or simply do not occur in all areas , or the age of onset does not correspond with the classic one.
- Related article: "The 4 types of Autism and its characteristics"
Autism spectrum disorders
Autism spectrum disorders are characterized by deficits in communication and in social interaction and alterations in behavior patterns ; Specifically, repetitive behaviors and restricted interests usually occur. Intellectual functional diversity, developmental delays and sensory problems also appear frequently.
The fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), which is used as a reference by many clinical psychologists but has received a large number of criticisms, redefined the pervasive developmental disorders described in the DSM-IV in a single category: Autism Spectrum Disorder .
Both the DSM-IV and the tenth edition of the International Classification of Diseases (ICD-10) divide autistic spectrum disorders or pervasive developmental disorders into different diagnoses: childhood autism or autistic disorder, the Asperger and Rett syndromes and the Disintegrative disorder of childhood.
Both classifications also include an extra category; in the case of the DSM-IV, it is the tailor made "Generalized development disorder not specified", which roughly corresponds to the diagnosis of "atypical autism" described in ICD-10 . Let's see what this disorder consists of.
- Related article: "Autism Spectrum Disorders: 10 Symptoms and Diagnosis"
What is atypical autism?
ICD-10 defines atypical autism as a generalized developmental disorder that does not meet the diagnostic criteria for autism ; This includes cases in which symptoms and deficits manifest after 3 years or do not occur in the three classic areas of autism: social interaction, communication and restricted, repetitive or stereotyped behavior.
According to this manual, atypical autism appears above all in people with severe intellectual deficits whose low level of functioning prevents them from certain behaviors, as well as in others with serious disorders of receptive language. As we will see later, the research suggests that these cases can be classified into three differentiated subgroups.
There is some debate about the specific characteristics of this form of autism. While some experts describe it as a mild variant of classic autism, others consider that their clinical characteristics and the relationship with other alterations makes that the atypical autism deserves to be considered as a differentiated disorder.
In general, it seems that studies indicate that the average severity of cases of atypical autism would be between that of classic autism and that of Asperger syndrome, which is associated with better social and cognitive functioning. However, given its diagnostic characteristics, atypical autism is an entity composed of very diverse cases.
- You may be interested: "How to help a child with Asperger's Syndrome?"
Subgroups of atypical autism
A study by Walker and other authors (2004) published in the Journal of the American Academy of Child & Adolescent Psychiatry compared the level of functioning of children with autistic disorder, Asperger syndrome and atypical autism.
This research team identified three differentiated subgroups who met the diagnostic criteria of classic autism, in addition to finding that in general it is a mild variant of the classic.
1. With limited stereotypes
The most common subgroup of atypical autism, which encompasses more than 50% of cases, is of girls and boys who meet all the diagnostic criteria of autistic disorder but who present reduced signs in the area of repetitive behavior . This means that social deficits are much more significant than stereotypies and the restriction of interests.
two.Incomplete autism criteria
According to this research, 25% of people with atypical autism present symptoms and signs in the three areas relevant to diagnosis (communication, interaction and stereotyped behavior), although they are not sufficiently marked to meet the criteria. This subgroup would include many cases of autism with severe intellectual deficit.
3. High performance
The third set of cases keeps similarities with Asperger's syndrome It is characterized by a relatively normal functioning of language, but this diagnosis can not be made because there is a delay in linguistic development and / or relevant cognitive deficits. The proportion of this subtype is also about 25%.
- Maybe you're interested: "Asperger's syndrome: 10 signs to identify this disorder"
Bibliographic references:
- American Psychiatric Association (2002). Diagnostic and Statistical Manual of Mental Disorders DSM-IV-TR. Barcelona: Masson.
- American Psychiatric Association. (2013). Diagnostic and Statistical Manual of Mental Disorders: DSM-5. Washington, D.C: American Psychiatric Association.
- World Health Organization (2003). ICD-10. Clinical descriptions and diagnostic guidelines. Madrid: Mediator.
- Walker, D.R., Thompson, A., Zwaigenbaum, L., Goldberg, J., Bryson, S.E., Mahoney, W.J. & Szatmari, P. (2004). Specifying PDD-NOS: a comparison of PDD-NOS, Asperger syndrome, and autism. Journal of the American Academy of Child & Adolescent Psychiatry, 43 (2), 172-180.
