‘Asperger's syndrome dropped from psychiatrists' handbook’, is the headline in The Guardian. The news is based on a press release from the American Psychiatric Association (APA) announcing the approval by their Board of Trustees of a revised fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). The DSM was first published in 1952 and is often referred to as the 'psychiatrists' bible' in the US.
The DSM is essentially designed to be a ‘user manual to diagnose mental illness’ – providing US psychiatrists with clear definitions of what pattern of symptoms correspond to specific conditions. This fifth revision, which has been a controversial issue of ongoing debate among psychiatrists and medical ethicists, is due out in May 2013.
One (amongst many) of the controversial decisions taken by the panel, made up of over 1,500 mental health experts, involved in drawing up the new draft guidelines, is to remove Asperger's syndrome as a separate diagnosis and replace it within the term ‘autism spectrum disorder’.
In the terminology of the DSM-5 – Asperger's syndrome would be seen as being at the ‘upper end’ of the autistic spectrum disorder (ASD). That means people with this type of ASD would normally have unaffected intelligence and language development, but would have milder symptoms affecting social interaction, behaviour and language comprehension.
A message about DSM-5 written by the president of the APA (PDF, 105Kb), Dr Dilip Jeste, touches on the complexities and challenges of revising an established diagnostic system, as reported in the media. These include conflicting views among experts and the under-diagnosis and over-diagnosis of patients.
Dr Jeste also says that narrowing diagnostic criteria is often blamed for excluding some patients from insurance coverage in the US, yet efforts to diagnose more patients are sometimes criticised for expanding the market for the pharmaceutical industry.
The chair of the taskforce responsible for overseeing the DSM-5 revisions, Dr David Kupfer, said: ‘Our work has been aimed at more accurately defining mental disorders that have a real impact on people’s lives, not expanding the scope of psychiatry’.
Despite the media hype, the revised classifications in DSM-5 will have limited impact on individuals who receive mental health care in the UK, at least in the short-term.
Psychiatrists in the UK tend to use the World Health Organisation’s International Classification of Diseases (ICD) system to diagnose mental health conditions, rather than DSM, which is used in the US.
Also, the term ‘autistic spectrum disorder’ (and the concepts underpinning it) have been widely used in the UK for many years. However, in the long-term, it is difficult to predict the potential impact the DSM-5 will have on the future diagnosis and treatment of mental health conditions.
Earlier versions of the DSM have had considerable influence, both in the US and across the world, in shaping opinions and driving research agendas. For example, it was the publication of the previous version (DSM-4) in 1994 that helped ‘popularise’ attention deficit hyperactivity disorder.
The DSM-5 (the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders) is produced by the American Psychiatric Association (APA) and is the diagnostic manual used by US clinicians and researchers to diagnose and classify mental disorders. The Diagnostic and Statistical Manual (DSM), first published in 1952, has undergone several revisions to take into account progress in medical and scientific knowledge and an advanced understanding of mental illnesses.
The DSM-5 is set for publication in May 2013 and will be a revision of the DSM-4 that was produced nearly 20 years ago.
According to a message from APA President, Dr Jeste, the DSM-5 reflects the best scientific understanding of psychiatric disorders and will optimally serve clinical and public health needs. Dr Jeste says ‘the hope is that the DSM-5 will lead to more accurate diagnoses, better access to mental health services, and improved patient outcomes.’
The DSM is broadly based on the classification system published by the World Health Organization (WHO), called the International Classification of Diseases (ICD).
The ICD system is used by the UK and other members of the WHO. It allows doctors to look at clusters of symptoms to form diagnoses for all health-related conditions, including mental health conditions.
The current version is ICD-10, and it is ICD-10, rather than DSM, that psychiatrists in the UK predominantly use to diagnose mental health conditions.
Autism and Asperger’s syndrome are both part of a range of related developmental disorders, which are characterised by:
The main difference between autism and Asperger’s is that people with ‘classic autism’ tend to have some degree of intellectual impairment. According to the press release, several categories from DSM-4 (including Asperger’s syndrome) will be replaced by a single diagnostic category of autism spectrum disorders in DSM-5. The following disorders will be incorporated under the diagnosis of autism spectrum disorders:
The press release says that this is to help more accurately and consistently diagnose people with autism. This does not mean that Asperger’s syndrome is being removed from the DSM classification system, only that it is being placed under a single diagnostic category.
Under ICD-10, both autism and Asperger’s syndrome are classed under what are known as ‘pervasive developmental disorders’ – pervasive meaning that the characteristic features of these conditions (for example, social interaction and communication problems) are a feature of the person's functioning in all life situations.
According to the press release, the DSM-5 will include approximately the same number of disorders that were included in the DSM-4.
Additional mental disorders set to be included in the DSM-5 are:
The revised manual (DSM-5) will include a section on conditions that require further research before their consideration as formal disorders. This section will include:
Disorders that will not be included in the revised manual (DSM-5) include:
Other changes to the DSM-5 reported in the press release include:
Until the publication of the DSM-5 in May 2013, there will be no changes to diagnoses of mental disorders. Importantly, the DSM-5 is a US publication, so its main impact will be in the US where clinicians use the DSM-5 to diagnose mental disorders.
Clinicians in the UK predominantly use the ICD-10 system to diagnose mental disorders, while the DSM classification system is mostly used for research purposes.
As mentioned, in the long-term, the new version of the DSM may have long-term healthcare, as well as cultural and political, implications that are impossible to predict.