A strategic series of revisions to the Diagnostic and Statistical Manual on Mental Disorders, prompted by Lorna Wing and her colleagues in London, were chipping away at Kanner’s monolithic edifice from the inside. Pervasive Developmental Disorder – Not Otherwise Specified (PDD-NOS) and Asperger’s syndrome were added to the manual in 1994. By recasting the DSM criteria, it was possible for children who would have been excluded from support to get services previously excluded from them: access to education, behavioural therapy, insurance reimbursement, and other essential services. By the end of the decade, however, the startling rise in diagnoses – and the alarms in the media that autism had become an epidemic – took all by surprise.
Infantile autism was added to the DSM-III in 1980, removing from the swamp of schizophrenia, and establishing it as the core of a new category of “pervasive developmental disorders”. Autism was framed narrowly in terms of its two cardinal signs: “pervasive lack of responsiveness to other people” coupled with “resistance to change”. The onset was specified as before 30 months,” which ruled out virtually all the kids who would be later diagnosed with Asperger’s syndrome. To accommodate kids who suffered a loss of skills after 30 months, there was “Childhood-Onset Pervasive Developmental Disorder” (COPDD). It was described as being even rarer than autism. Few clinicians bothered with the ill-conceived diagnosis. In the 1987 DSM-III-R, the word infantile was finally gone for good and the COPDD diagnosis was also dropped. Crucially, the non-negotiable checklist had been replaced by a banquet of options to pick and choose from: at least 8 of the following 16 to include two items from A, one from B, and one from C. This ensured that fewer children would slip through the diagnostic net. The descriptions of these behaviours were also made less absolute. The new criteria could be applied to a much larger and more diverse population. This triggered a significant rise in diagnoses, as it was better at picking up on cases of autism at every level.
However, PDD-NOS was subthreshold autism. It quickly eclipsed autistic disorder to become the most commonly used PDD diagnosis. Like Asperger’s syndrome, it was an autism diagnosis that didn’t contain the word autism and thus was more readily accepted by parents and healthcare workers.
By the end of the process, autism had been transformed into something that Kanner would have barely recognized.
Estimates of autism prevalence began to increase worldwide after the publication of the DSM-III and DSM_III_R. This was no surprise to Lorna Wing: awareness of autism among professionals was dramatically increasing at the same time that the boundaries of the condition were expanded realigning themselves with the reality of the spectrum – to 1 in 100 children. In England, between 1990 and 2000, cases increased by an astonishing 22% on average per year and would never level off again.
A similar evolution was taking place in the USA prompted by amendments to the Disabilities Education Act. Clinicians applied the diagnosis more readily and increased awareness among school teachers and staff. Few parents could afford Lovaas’s forty hours of ABA a week to achieve “full recovery”.
Assessment tools. TEACH introduced the Child Autism Rating Scale (CARS) in 1980 which was particularly good at distinguishing autism from other forms of developmental delay, such as intellectual disability. The scale was highly reliable and consistent, and its scores matched well with the assessment by other means. New raters could be trained in a single one-hour session. CARS also provided an accurate picture of the child’s strengths, which was crucial for developing an appropriate plan for education. The second edition of CARS was introduced in 1988 and was easier to use and could be used to diagnose teenagers and adults.
An international team introduced the Autism Diagnostic Observation Schedule (ADOS) to assess communication, social interaction, and play, first in children and then extended to teenagers and adults.
The clinical population was changing enormously but the clinical outcome barely changed – 50% of the autistic population are mute and remained that way. Even high-IQ autistic adolescents sustained rudimentary social relationships. The outlook looked relentlessly monochrome.
Asperger’s syndrome knowledge was still in its infancy as it shaded into subclinical eccentricity – was it truly a mental disorder or a common personality type? Asperger’s was clearly a disorder of social impairment subject to social context.
The term Aspie would become a badge of honour and defiant pride within a decade. The genie of autistic intelligence was posed to escape the bottle in which it had been trapped for 50 years. The DSM-IV added Asperger’s resulting in more families gaining access to services. The DSM-IV was an international smash that earned $100 million. It was a 900-page behemoth that found its way everywhere. Instead of requiring that a child display impairments in social interaction, communication, and behaviour before getting a diagnosis of PDD-NOS, the criteria substituted the word “or” for “and”. This typo went uncorrected for 6 years and about 75% of children identified as not having the disorder (true negatives) were incorrectly identified as having it, creating a true autism epidemic and a statistical nightmare.
