Asperger Syndrome

Excerpt

Asperger syndrome (AS) was first described by Hans Asperger in 1944 as the behavioral characterization of individuals with difficulties in communication and social interaction. Since then, there has been considerable interest and debate surrounding AS. Although AS was introduced as a distinct diagnostic category in the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-4, 1994), its diagnostic label was removed from the subsequent edition, the Diagnostic and Statistical Manual of Mental Disorders (DSM–5), almost two decades later. Instead, AS was incorporated into a broader category known as autism spectrum disorders (ASD). This change reflected a growing recognition that autism encompasses a spectrum of experiences with varying degrees of severity and a wide range of associated characteristics.

Autism spectrum disorders (ASD) encompass a range of neurodevelopmental conditions characterized by diverse degrees and manifestations. Typically emerging in early childhood, these disorders are marked by challenges in social communication and interaction and behavioral patterns that involve restricted interests and repetitive behaviors. The changes made to the classification of ASD in DSM-5 sparked controversy regarding the loss of the distinct Asperger identity. This shift in classification continues to be a topic of debate within the literature, as discussions revolve around the formulation and inclusion of AS within the broader ASD framework. Given the extensive historical background of AS, its distinct semiotics, and the relatively characteristic clinical presentations, specialists still utilize this diagnosis as a subtype of ASD characterized by the absence of language delay and a normal or above-average IQ.

This topic review will describe the essential aspects of autism spectrum disorder and Asperger syndrome. For greater transparency, the following have been referred to:

1. Asperger syndrome (AS): identified as a subgroup within the category of pervasive developmental disorders (PDD) as per the DSM-4-TR classification.

2. ASD: categorized as a range of neurodevelopmental conditions in the DSM-5.

3. Autism spectrum disorder of an Asperger syndrome type (ASD-AS): is a specific subgroup in the DSM-5 classification of ASD. ASD-AS is characterized by individuals who exhibit symptoms consistent with ASD, specifically at Level 1 severity, without accompanying intellectual impairment

Historical Perspective

In 1944, approximately one year after psychiatrist Leo Kanner first described infantile autism, Hans Asperger published a case report introducing a condition called "autistic psychopathy."In 1980, the American Psychiatric Association (APA) officially acknowledged autism as a distinct category in the DSM-3, where it was initially presented as "infantile autism." Following that, in 1981, psychiatrist Lorna Wing reignited research on Asperger's work and rebranded "autistic psychopathy" as "Asperger syndrome." A few years later, in 1989, the first diagnostic criteria for Asperger syndrome were proposed.

The 10th Revision of the International Classification of Diseases (ICD-10), introduced in 1993, was the first significant classification system to recognize Asperger syndrome (AS). Then, in 1994, AS was formally introduced as a distinct entity in the DSM-4. It was categorized within PDD alongside autism spectrum disorder, marking an important milestone in recognizing and understanding AS as a separate diagnostic category. While during this period, researchers were focused on developing measures to diagnose AS and differentiate it from high-functioning autism (HFA), the DSM-5 removed the diagnostic category of AS in 2013. The World Health Organization (WHO) also followed a similar approach in ICD-11, which came into effect in 2022.

DSM Classification

The systematic description of psychiatric disorders is complicated, particularly in child and adolescent psychiatry. Asperger Syndrome was included in the DSM-5-TR in the large family of PDD. PDD has five subtypes:

1. Autism spectrum disorder

2. Asperger syndrome

3. Childhood disintegrative disorder

4. Pervasive developmental disorder not otherwise specified (PDD-NOS)

5. Rett syndrome

In DSM-IV-TR, the symptoms and clinical specifiers for autistic disorder within the pervasive developmental disorders (PDD) category fell into three broad categories: social interaction, communication, and restricted and repetitive behavior. The diagnostic criteria for Asperger syndrome (AS) used to include:

1. Individuals exhibiting at least two symptoms of social impairment and at least one symptom each from the category of communication deficits and restricted, repetitive behaviors (RRB).

2. Delayed or impaired functioning in at least one of the following areas: social interaction, language as used in social communication, or symbolic or imaginative play with onset before the age of three years.

3. Individuals who met the diagnostic criteria for autistic disorder (or another specific PDD) would not meet the criteria for AS. In such cases, the diagnosis of autistic disorder would take precedence.

AS, as contrasted with autistic disorder, was differentiated based on several key factors, as outlined:

1. Absence of diagnostic criteria in the communication domain

2. Lack of a requirement for onset before age 3

3. Addition of criteria specifying the absence of a language delay

4. Addition of criteria specifying the absence of a deficit in cognitive development

This classification proposed a differential diagnosis between AS and high-functioning autism (HFA), a type of autistic disorder characterized by normal cognitive functioning. The differential diagnosis between AS and HFA sparked significant debate due to uncertainties in defining the specific criteria for AS and the clinical overlap between the two conditions. This debate is reflected in the literature, which has produced contradictory results regarding the distinctiveness of AS and HFA. While research has identified nuanced differences between the two disorders, most studies have emphasized the similarities between AS and HFA.

Ultimately, the DSM-5 removed PDD and its categorization and merged four subtypes into one category with a continuum named autistic spectrum disorders (ASD). This significant alteration was due to the assumption that PDD subgroups cannot be differentiated from one another certainly and reliably. As a result, several changes were made in the classification system, including the following:

1. Elimination of PDD and its subtypes.

2. Creation of a new diagnostic category called autistic spectrum disorders (ASD), encompassing autistic disorder, Asperger syndrome, childhood disintegrative disorder, and PDD-NOS.

3. Addition of three levels of severity for ASD. These severity levels help provide a more comprehensive understanding of the individual's functional impairments and support needs.

4. Shifting from the previous PDD classification, which consisted of 3 domains, to the ASD classification, which comprises 3 domains. These 2 domains encompass:

   1. Impaired social communication and interaction

   2. RRB, interests, and activities.

5. Addition of sensory symptoms in the RRB component of diagnostic criteria.

6. Changing the specification of the age of onset from age 3 to "early childhood."

7. Creation of a new diagnostic category called "social communication disorder" (SCD) to include individuals with difficulties in social communication and interaction but who do not meet RRB criteria found in ASD.

8. Removal of Rett syndrome from the classification based on recent genetic data.

9. Including social communication and interaction-related deficits in one criterion while excluding the deficit related to spoken language.

Controversy over the New Classification of ASD

The new classification has faced criticism in the literature, with some authors suggesting that it may lead to narrower criteria for ASD. As a result, there is concern that certain individuals, particularly those who are cognitively able or previously diagnosed with AS or PDD-NOS (pervasive developmental disorder not otherwise specified), may no longer meet the criteria for an ASD diagnosis. In summary, the main argument is that while the reduced sensitivity of the new ASD classification may increase specificity, it can have negative implications for service eligibility and the ability of researchers to integrate information and data from studies conducted under these criteria. On the other hand, some authors argue that eliminating the specific diagnostic category for AS may lead to increased stigma toward individuals previously diagnosed with AS. This argument is based on the assumption that societies with a negative perception of autism as a significant disability may stigmatize individuals falling under the ASD umbrella. In contrast, AS has been associated with more positive stereotypes, and its removal as a separate category could potentially contribute to losing those positive associations.

Thus, the new inclusion of AS in the category of ASD may have a negative effect on the identity of the individuals who have adopted this label as an identity. However, the literature on the potential impact of the DSM-5 changes on individuals previously diagnosed with AS is limited. The results of the discussions surrounding the changes in the ASD classification can be categorized into three groups: those who support the changes, those who oppose the changes, and those who express mixed feelings about the changes.