NICE’s new draft guideline for PTSD fails to mention how ICD-11 has profoundly shifted how we diagnose this disorder
In December 2018 the National Institute for Health and Care Excellence (NICE) is scheduled to publish its new guideline on the treatment of post-traumatic stress disorder (PTSD). The guideline covers recognising, assessing, and treating PTSD, but only evidence on prevention and care has been updated. The draft guideline sent out for consultation reflects the diagnostic changes introduced by DSM-5 in 2013, but makes no mention of the fact that there occurred this year what—in many people’s opinion—is the greatest revolution in the diagnosis of PTSD since it was first introduced in 1980.
The PTSD diagnosis in DSM-5 is the most complex in the entire manual, consisting of 20 symptoms arranged into four symptom clusters, along with four additional criteria. It has been calculated that there are over 600 000 combinations of symptoms that qualify for the diagnosis. It is associated with high levels of comorbidity and is under-recognised in general practice,and after major disasters.
However, in 2018 the World Health Organization issued for member states’ review the 11th edition of the International Classification of Diseases (ICD-11). PTSD can now be identified by asking after only six symptoms (representing 27 combinations of symptoms), and more severe presentations can be identified as complex PTSD. Compared to DSM-5, a wider variety of traumatic situations known to produce PTSD, such as being treated in intensive care  or having a psychotic episode, can qualify for the diagnosis.
The aim of the WHO has been to improve the clinical utility of diagnoses so that disorders can be more easily recognised and treated worldwide. In the case of PTSD, this aim has been accomplished by focusing on the symptoms of PTSD that distinguish it most effectively from other disorders.
In addition to functional impairment, the diagnosis requires the presence of one out of two symptoms indicating the event is being re-experienced as though it were happening in the here and now (in the form of nightmares or intrusive memories/flashbacks); one out of two symptoms indicating deliberate avoidance (avoidance of internal reminders such as thoughts or external reminders such as places or people); and one out of two symptoms indicating a continuing sense of threat (hypervigilance or exaggerated startle response). Non-specific symptoms such as irritability, sleep disturbance, and loss of interest have been removed.
Patients who meet these criteria for PTSD, but in addition have emotion regulation difficulties, negative views of self, and impaired relationships, qualify for a sibling diagnosis, complex PTSD. Studies that have empirically evaluated these changes on four continents have supported the proposed symptom structure and the distinction between PTSD and complex PTSD, as well as identifying a likely small reduction in the resulting prevalence of PTSD in adults.
Why do these changes matter? Perhaps most importantly, they make the job of recognising PTSD in non-specialist settings much easier, although guidance is also required for mental health professionals who routinely diagnose patients and may not be familiar with the new criteria. The changes also draw attention to the different levels of severity of PTSD, which has implications for treatment planning and commissioning. The new NICE guideline acknowledges that some PTSD presentations may require more than the standard eight to 12 sessions of trauma focused psychological treatment, and even refers to ICD-11 “complex PTSD,” without fully explaining how the diagnosis of PTSD has changed.
The 2005 NICE guideline on PTSD has been enormously influential and was, for example, used to underpin and justify the mental health response to the London bombings of that year. The NHS relies on NICE to signal important new developments, and in this case to identify that ICD-11 has markedly changed the policy and practice context going forward. Including these developments in the new NICE guideline is essential to ensure that the new diagnostic framework is widely disseminated and that its benefits are reflected in everyday clinical decision making.
Chris R Brewin, professor of clinical psychology, University College London.
Competing interests: I am a member of the WHO International Advisory Group for the Revision of ICD-10 Mental and Behavioural Disorders and of the Working Group on Classification of Stress-Related Disorders. The views expressed are those of the author and not the WHO.
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