There is no clinical difference between autism and autism spectrum disorder. They refer to the same condition. “Autism spectrum disorder” (ASD) is the formal diagnostic term used in medical and psychiatric settings, while “autism” is the everyday shorthand. The reason these terms sometimes seem like separate things comes down to a history of diagnostic labels that changed significantly in 2013.
Why the Names Can Be Confusing
Before 2013, the diagnostic manual used by psychiatrists and psychologists in the United States listed several separate conditions under a broader umbrella. These included Autistic Disorder, Asperger’s Disorder, and Pervasive Developmental Disorder, Not Otherwise Specified (PDD-NOS). Each had its own criteria. Autistic Disorder was the “classic” diagnosis, typically involving significant delays in speech and social development. Asperger’s Disorder was diagnosed when a person had social difficulties and repetitive behaviors but no significant language delay. PDD-NOS was a catch-all for people who showed some traits but didn’t fully meet the criteria for either of the other two.
In practice, the lines between these diagnoses were blurry. A major research review found insufficient evidence to establish Asperger’s Disorder as a condition truly distinct from high-functioning Autistic Disorder. Clinicians in different regions applied the labels inconsistently, which meant the same child could receive different diagnoses depending on where they were evaluated.
The 2013 Shift to One Diagnosis
When the American Psychiatric Association published the fifth edition of its Diagnostic and Statistical Manual (DSM-5) in 2013, it merged all three diagnoses into a single category: Autism Spectrum Disorder. The word “spectrum” was chosen deliberately to reflect the wide range of ways the condition presents, from people who need round-the-clock support to those who live independently with minimal accommodations.
Under the current criteria, a diagnosis of ASD requires difficulties in two core areas: social communication and interaction, plus restricted or repetitive patterns of behavior, interests, or activities. Sensory sensitivity, such as being strongly bothered by certain textures, sounds, or lights, was included as a recognized feature for the first time in this edition. Both areas of difficulty must have been present from early development, even if they weren’t recognized until later in life.
How the Spectrum Levels Work
Instead of separate diagnostic labels, the DSM-5 uses three severity levels based on how much support a person needs. These levels are assigned independently for social communication and for repetitive behaviors, so someone could be rated differently in each area.
- Level 1 (requires support): The person can communicate verbally and manage many daily tasks but struggles with social interactions, organization, or flexibility. This roughly corresponds to what was once called Asperger’s or “high-functioning autism.”
- Level 2 (requires substantial support): Social difficulties are noticeable even with support in place. The person may speak in short sentences or have markedly narrow interests that interfere with daily functioning.
- Level 3 (requires very substantial support): The person has severe challenges in communication, sometimes using very few words or none at all, and repetitive behaviors significantly limit independence.
These levels aren’t permanent labels. A person’s support needs can change over time with therapy, accommodations, or life circumstances.
How Other Countries Classify It
The World Health Organization’s International Classification of Diseases (ICD-11), used in most countries outside the U.S., also recognizes Autism Spectrum Disorder as a single neurodevelopmental condition. Both systems agree on the core features: persistent difficulties with social communication and repetitive or inflexible behaviors. The ICD-11 takes a slightly different approach to subcategories, though. Rather than severity levels based on support needs, it offers eight subcategories that distinguish between people based on intellectual ability and language development. It also allows a wider variety of symptom combinations, with 304 possible presentations compared to the more tightly defined criteria in the DSM-5.
What Happened to Asperger’s
Asperger’s Disorder no longer exists as an official diagnosis. People who were diagnosed with Asperger’s before 2013 now fall under the ASD umbrella, typically at Level 1. Many people who received that earlier diagnosis still identify with the term, and it remains common in conversation. But a clinician evaluating someone today would diagnose ASD and specify the support level rather than using the Asperger’s label.
How People Talk About It
In everyday conversation, most people simply say “autism” rather than the full clinical term. This isn’t inaccurate. It’s just the common-language version of the same diagnosis. Within the autism community, there’s an active conversation about language preferences that goes beyond the diagnostic label itself. A study of nearly 300 autistic adults found they overwhelmingly preferred identity-first language (“autistic person”) rather than person-first language (“person with autism”). Professionals who work in the field, by contrast, were more likely to use and support person-first phrasing. Neither is wrong, but the trend among autistic people themselves leans toward identity-first terms that treat autism as an integral part of who they are rather than something separate from them.
Current Prevalence
About 1 in 31 children aged 8 in the United States, or 3.2%, have been identified with ASD, according to the CDC’s most recent surveillance data. The condition is identified more than three times as often in boys as in girls, though growing awareness of how autism presents differently in girls is narrowing that gap over time. The rising prevalence numbers largely reflect broader diagnostic criteria, better screening, and increased awareness rather than a true increase in how common the condition is.