several puzzle pieces in rainbow colour laid out on a table in the shape of a heart

Autism, now also known as autism spectrum disorder (ASD), encompasses a wide range of conditions characterized by difficulties in social skills, communication skills, and emotional regulation challenges. 

Autism is not considered an illness or disease; rather, it signifies that the brain functions differently from neurotypical individuals. Symptoms of autism typically manifest before the age of three, leading to its classification as a developmental disorder. 

The Five Types of Autism Before DSM-5

Type of AutismDescription
Asperger SyndromeConsidered the “mildest” form of Autism, characterized by difficulties in social interaction, restricted interests, repetitive behaviors, and routines. Marked by strong verbal language skills and intellectual ability.
Kanner’s Syndrome or Classic Autistic DisorderOften depicted as the stereotypical form of Autism, with traits including repetitive movements, avoiding eye contact, language delays, and heightened sensitivity to light or sounds. An inclination toward routine and minimal interest in social interactions.
Childhood Disintegrative Disorder (CDD)Typically, children develop normally until around age three before experiencing a rapid loss of language, motor, social, and other skills acquired. Regression and late-onset delays are hallmarks, distinguishing it from other developmental disorders.
Rett SyndromeA unique genetic disorder predominantly affecting females, characterized by developmental stagnation and loss of purposeful hand skills. Features distinctive hand movements and slowed growth. Formerly classified as an autism spectrum disorder (ASD) but no longer under DSM-5.
Pervasive Development Disorder: Not Otherwise Specified (PDD-NOS)An umbrella term capturing individuals on the autism spectrum who don’t fully meet the criteria for any specific condition. Implies significant developmental issues without clear categorization.

In the previous Diagnostic and Statistical Manual of Mental Disorders (DSM) versions, Autism was categorized into five different types of Autism. Since the American Psychiatric Association (APA) released the latest version in 2013 (DSM-5), these previous 5 types of Autism have either been excluded or dissolved into a general “Autism Spectrum Disorder” (ASD) diagnosis. 

DSM-5 now categorizes ASD by 3 severity levels to indicate the level of support required based on the needs of social communication impairments and restricted, repetitive patterns of behavior. Even with the diagnostic revision, the 5 types of Autism cited in the previous versions of the DSM remain in the vernacular and may carry significance for those unfamiliar with the new diagnostic levels.

Let’s get acquainted with the previous five so that we may have a common baseline.

Asperger Syndrome

Considered the “mildest” form of Autism, Asperger Syndrome now falls under Level 1 Autism to require minimal support. Despite sharing common features with other ASD types, such as difficulties with social interaction and a tendency towards restricted interests, repetitive behaviors, and routines, Asperger Syndrome is marked by strong verbal language skills and intellectual ability. 

Kanner’s Syndrome or Classic Autistic Disorder

Kanner’s Syndrome is likely what people picture when they hear the word Autism, with classic stereotypical autistic traits of repetitive movements, avoiding eye contact, language delays, and heightened sensitivity to light or sounds. 

Leo Kanner’s work in 1943 was pivotal in the initial descriptions of autism spectrum disorders, leading to the evolution of diagnostic concepts up to DSM-5. 

Children diagnosed with Kanner’s Syndrome exhibit a strong inclination toward routine and often lack interest in their external environment. They tend to focus internally, showing minimal interest in social interactions. “Kanner’s syndrome” is one of the lesser used labels as the medical community has gained more understanding of how to assess and diagnose ASD based on specific skills.

Childhood Disintegrative Disorder (CDD)

Children with CDD typically develop normally until about age three before experiencing a rapid loss of language, motor, social, and other skills they had previously acquired. This regression and late-onset delays can occur over a few months and are a hallmark of CDD, distinguishing it from other developmental disorders.

Rett Syndrome

Rett Syndrome manifests as a unique genetic disorder predominantly affecting females. The syndrome landed itself on the autism spectrum due to shared characteristics, including developmental stagnation and loss of purposeful hand skills.

However, Rett Syndrome retains its uniqueness with features like distinctive hand movements and slowed growth. A child with Rett Syndrome develops typically until six to 18 months, when a noticeable delay in development occurs. 

Under DSM-5, Rett Syndrome is no longer classified as an autism spectrum disorder (ASD).

Pervasive Development Disorder: Not Otherwise Specified (PDD-NOS)

Pervasive Developmental Disorder-Not Otherwise Specified (PDD-NOS) was another category within the spectrum. It captures those individuals who fall into the autism spectrum but do not fully meet the criteria for any specific condition. PDD-NOS is an umbrella term implying a significant problem with development, but it’s unclear how to categorize the issue.

The Three Levels of ASD based on DSM-5

LevelDescription
Level 1: Requiring SupportHigher level of impairment; more severe symptoms include challenges with verbal and social communication, narrow interests, repetitive behaviors, and difficulty coping with changes.
Level 2: Requiring Substantial SupportThe most severe form involves significant challenges in social communication and restricted/repetitive behaviors, necessitating long-term assistance and intensive intervention.
Level 3: Requiring Very Substantial SupportMost severe form; significant challenges in social communication and restricted/repetitive behaviors, necessitating long-term assistance and intensive intervention.

In an attempt to understand the different types of autism, which we now know is a full spectrum along many factors of behaviors (e.g., social, communication, independence, emotional regulation, academic, language output, etc), the question remains: why do we care about labeling the different types of autism?

Knowing which type of autism does not clearly indicate what type of strategies will work for the individual to better their quality of life. Let’s see if the DSM-5 does a better job. 

Under the DSM-5, all “types” of autism are now considered “Autism Spectrum Disorders.” Diagnosticians now rate the severity of the ASD affecting the individual on a scale of levels 1, 2, or 3 based on their level of need within the domains of social communication skills and restricted, repetitive behaviors. 

Level 1: Requiring Support

Level 1 autism, also known as mild autism, is the least severe form of the disorder. Individuals with level 1 autism may experience difficulties in social situations, communication, and organization. 

They generally require some support to help them navigate these challenges. While they may exhibit some symptoms of autism, they are typically able to function with minimal support and intervention. This level was previously associated with terms like “Asperger’s syndrome” or “high-functioning autism.”

An individual diagnosed with level 1 autism may be verbal, have eye contact, and be able to stay in the mainstream classroom or hold a job, but experience difficulties in maintaining a conversation, being hypersensitive to stimuli, and understanding nonverbal communication (e.g., body language and tone of voice).

Level 2: Requiring Substantial Support

Level 2 autism, also known as “requiring substantial support,” represents a higher level of impairment compared to Level 1 within the Autism Spectrum Disorder (ASD). 

Individuals with Level 2 autism exhibit more severe symptoms than those at Level 1, requiring substantial support in social situations. 

They may have more obvious challenges with verbal and social communication, narrow interests, repetitive behaviors, and difficulty coping with changes in routine.

Level 3: Requiring Very Substantial Support

Level 3 autism, also known as severe autism, is the most severe form of the disorder. Individuals with level 3 autism exhibit severe deficits in functioning, often requiring long-term assistance. 

This level is characterized by significant challenges in social communication and restricted/repetitive behaviors, necessitating very substantial support for daily living. It represents a high level of impairment across various areas of development and typically requires intensive intervention and support to address the complex needs associated with this level of autism.

The Importance of Early Diagnosis of Autism Spectrum Disorder

Early diagnosis of autism is important for several reasons. First, early diagnosis allows children to benefit from early intervention therapies, support, and school accommodations from an early age, which can significantly improve their development and quality of life. 

In places like British Columbia, Canada, a diagnosis allows parents to access government funding for autism service providers to provide support and interventions for their child. An early diagnosis maximizes the use of the full funding amount for children until 6 years of age before the subsidized amount drastically reduces

Second, early diagnosis helps parents and caregivers understand the child’s needs and challenges, allowing them to provide appropriate support and interventions. 

Finally, early diagnosis can help identify and address any co-occurring conditions or developmental delays, further improving the child’s overall well-being.

Identifying suitable strategies enables professionals to ensure optimal care and guidance are provided. Crucially, these strategies should be flexible, adapting as the individual evolves, reflecting shifts in their needs, abilities, and challenges.

Conclusion – Diagnoses still missing the point

Understanding the different types of autism isn’t about labeling but about discovering the variety that exists in the autism spectrum. When an individual meets the diagnostic criteria or is labeled with a specific type of autism, it still doesn’t indicate the level of support they need. 

The latest version DSM-5 hoped to address the latter point to rate the level of severity based on two categories: social and communication skills and restrictive, repetitive patterns of behaviors and interests. 

However, it doesn’t address the complexities of the autism spectrum disorder, nor does it indicate the specific need for contextual support. For example, it doesn’t specify that an individual may need a high level of support at school, but low level of support at home. 

Thus, it is important to seek the proper intervention that will take into account the individual’s needs and the environmental context in which they live. A diagnostic label cannot implicate what type of intervention and support are required. 

The right service provider should do their due diligence in carefully conducting individualized assessments to determine specific skill gaps and design a treatment package that is tailored to meet the needs of the individual, improving any social and communication skills and functional life skills to promote their integrity and independence, thereby enhancing their quality of life.