Autism Spectrum Disorder (ASD) is a complex, lifelong neurodevelopmental condition that influences how a person communicates, interacts with others, and experiences the world. The condition is characterized by challenges in social communication and the presence of restricted or repetitive behaviors and interests. Understanding when this condition was first formally recognized requires tracing the scientific efforts that separated it from other developmental or psychiatric diagnoses.
The 1943 Landmark Study
The formal diagnosis of autism in Western medical literature is traced back to 1943 with the publication of a paper by Dr. Leo Kanner, a child psychiatrist at Johns Hopkins Hospital. His seminal work, titled “Autistic Disturbances of Affective Contact,” presented detailed case studies of 11 children he had observed between 1935 and 1943. Kanner’s paper defined a distinct syndrome, establishing it as separate from previous diagnoses like “feeble-mindedness” or childhood schizophrenia.
The first child in this study, known as Donald T., became the first formally described case in the literature, presenting with behaviors such as an intense desire for aloneness and an inability to relate to people from infancy. Kanner coined the term “early infantile autism” to describe this unique pattern of behavior, borrowing the word “autism” from Swiss psychiatrist Eugen Bleuler, who had used it to describe inward, self-absorbed aspects of schizophrenia. Kanner’s cases exhibited a profound lack of social reciprocity, a strong insistence on the preservation of routine and sameness, and a preoccupation with objects rather than people.
Other features noted by Kanner included communication challenges, such as the repetition of words or phrases, known as echolalia, and an unusual use of language. The children also displayed repetitive motor behaviors, such as hand flapping or spinning objects, along with highly restricted and intense interests. This meticulous documentation of a consistent set of behaviors marked the moment the condition was first formally identified and described as a unique clinical entity.
The Concurrent European Research
While Kanner’s work was establishing the diagnosis in the United States, a parallel investigation was occurring in Europe by Austrian pediatrician Dr. Hans Asperger. In 1944, Asperger published his own paper, “Die ‘Autistischen Psychopathen’ im Kindesalter,” detailing a group of boys with similar social impairments. Asperger’s work described children who often had higher verbal abilities and cognitive skills, leading to a focus on slightly different characteristics than Kanner’s group.
Asperger’s patients displayed social difficulties, an intense absorption in specialized interests, and clumsy motor skills, but their language development was often not delayed. Because his work was published in German during wartime, it remained largely unknown in the English-speaking world for several decades, preventing direct collaboration.
Kanner’s definition focused on a more severe presentation, often including intellectual disability, which became known as “classic autism.” Asperger’s description focused on what would later be known as Asperger Syndrome, characterized by social difficulties combined with relatively preserved intelligence and language.
From Infantile Autism to the Spectrum
The concept of autism remained narrow, largely defined by Kanner’s “early infantile autism” until the 1970s, when researchers began to challenge the limited view. British psychiatrist Dr. Lorna Wing played a significant role in advocating for a broader understanding of the condition. Her epidemiological research identified a prevalence of social impairment far exceeding the estimates for classic Kanner autism, leading her to propose the concept of a continuum, or “spectrum,” of autistic conditions.
This evolving understanding began to be formally incorporated into international diagnostic systems. Autism was officially recognized as a distinct developmental disorder, separate from schizophrenia, with its inclusion in the third edition of the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders (DSM-III) in 1980. The DSM-III-R revision in 1987 shifted the name from “infantile autism” to “autistic disorder,” reflecting that the condition persists beyond childhood.
The diagnostic criteria continued to evolve. In the DSM-IV, various related conditions, including Asperger’s Disorder, Autistic Disorder, and Pervasive Developmental Disorder Not Otherwise Specified (PDD-NOS), were grouped together under the umbrella of Pervasive Developmental Disorders.
The most significant shift occurred with the publication of the DSM-5 in 2013, which consolidated all these separate diagnoses into the single category of Autism Spectrum Disorder (ASD). The new manual described ASD based on two core domains: deficits in social communication and interaction, and restricted, repetitive patterns of behavior, formally recognizing the wide range of presentations under one unified spectrum.