| The changing spectrum of autism

The DSM-5 and its plan to redefine mental illness

In May 2013, the American Psychiatric Association (APA) will release the fifth iteration of its Diagnostic and Statistical Manual of Mental Disorders (DSM-5), redefining the way psychiatrists diagnose their patients. The proposed changes to the diagnostic criteria for autism and its related disorders have drawn ire.

Autism is a neurological condition characterized by developmental disabilities in social interaction and communication, along with repetitive and obsessive behaviours. People with the disorder range from high-functioning individuals to those who are more severely affected; it is often diagnosed with conditions including intellectual impairment, learning disabilities, and ADHD. Autistic individuals often need treatment to increase quality of life and mitigate problematic behaviours: this includes costly one-on-one sessions in behavioural therapy, physiotherapy, counseling, special nutrition, and medication. More importantly, however, is that in many cases a formal diagnosis of autism is necessary for an individual to get access to affordable care.

In the DSM-5, Asperger’s and Pervasive Developmental Disorder-Not Otherwise Specified (PDD-NOS) will be subsumed under the general category of autism spectrum disorder (ASD). Patient’s illnesses will be classified according to severity, rather than as individual and definite, disorders. While the criteria will be more specific and less prone to false positive diagnoses, some in the mental health community see the new criteria as alarmingly narrow. These critics worry that future generations of autistic patients – especially those who are higher-functioning individuals – might be overlooked in the new method of diagnosis.

It’s possible that the tighter criteria are a response to the reality that autism rates have skyrocketed in past years. In 2000, the prevalence rate was one in 150 North American children, while today it is estimated that one in 110 children are affected, according to the US Center for Disease Control (CDC). In Canada, an estimated 190,000 Canadians have been diagnosed with autism.

In a 2011 article published in Psychology Today, Allen Frances – the chairman of DSM-IV Task Force – cited the introduction of looser clinical diagnostic criteria as a possible factor in this increase in autism diagnoses. Specifically, the publication of the fourth Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) in 1994 brought with it a new and expanded definition for autism spectrum disorder (ASD); until then, autism had been one of the most narrowly defined disorders in the DSM, reserved only for those who manifested the severest symptoms. The DSM-IV included the new diagnosis of Asperger’s Disorder, which was “surprisingly popular,” according to Frances. To explain this increased popularity, Frances describes the widespread media attention given to Asperger’s, and the decreased social stigma attached to the disorder. Also important were the “expanded school and therapeutic services whose reimbursement often required an autism diagnosis.”

The more stringent criteria in the DSM-5 are seen by some as an attempt to limit what is seen as a tendency towards over-diagnosing autism, and consequently stem a growing drain on resources and funding. David J. Kupfer, the chairman of the DSM-5 Task Force revising the diagnostic criteria, described it as a “cost issue” in an article in the New York Times. Catherine Lord, another member of the Task Force and director of the Institute for Brain Development at New York Presbyterian Hospital, was quoted in a Scientific American article on the issue as saying that “if the DSM-IV criteria are taken too literally, anybody in the world could qualify for Asperger’s or PDD-NOS” and that the new DSM-5 criteria are meant to improve specificity and reduce the amount of kids who are misdiagnosed.

After the draft that proposed the diagnostic criteria for ASD was released, however, two studies were conducted which warn that the new criteria will exclude many currently diagnosed autistic individuals, especially on the higher functioning end. The Clinic of Child Psychiatry at the University of Oulu in Finland released a study last June titled “Autism spectrum disorders according to DSM-IV-TR and comparison with DSM-5 draft criteria.” The study’s conclusions were that, “DSM-5 draft criteria were shown to be less sensitive in regard to identification of subjects with ASDs, particularly those with Asperger’s syndrome and some high-functioning subjects with autism.” Dr. Fred Volkmar of Yale’s Child Study Centre, along with colleagues Brian Reichow and James McPartland, released a study using data from a 1993 survey of 372 high-functioning children and adults to see how they would fare under the DSM-5 criteria. Only 45 per cent would qualify as having ASD; 75 per cent of people with Asperger’s and 85 per cent of those with PDD-NOS would not be diagnosed under the new classifications.

A field study of the new DSM-5 criteria titled “Validation of proposed DSM-5 criteria for autism spectrum disorder” released by the Center for Pediatric Behavioral Health and the Center for Autism concluded that while increased specificity would reduce the number of false positive diagnoses, “phase II testing of DSM-5 should consider a relaxed algorithm, without which as many as 12 per cent of ASD-affected individuals, particularly females, will be missed.” The worries of possible autistic individuals being denied the diagnosis and subsequent support and resources they need is worrying, especially considering that certain groups are already under-diagnosed – such as racial minorities, women, and people of lower socioeconomic status.

Bryan King of the Neuro-developmental Disorders workgroup at the APA asserted that there are some upsides to the consolidation of the categories that fall under the ASD, since certain treatments, only approved by the FDA for one autism-related disorder, aren’t approved or indicated for another. The definition of autism in the DSM-5 has great potential for improving the specificity of diagnosis and helping individuals get the specially tailored treatment options they need for their particular symptoms. The criteria for the DSM-5 are due to be consolidated by December, giving hope that the APA will find a way to provide diagnostic tools which will benefit all those who suffer from mental illnesses.


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