GCP.Network Study Results

Brief Report on GCP.Network Study on Disorders Specifically Associated with Stress


At the time of the study 3 669 GCPN members qualified to participate in the study in 1 of the 3 available languages. 1 738 GCPN Members completed the study: 889 in English, 440 in Japanese and 409 in Spanish.


Mean age: 46 yrs (SD~11 yrs)
Mean professional experience: 16 yrs (SD~10 yrs)
Male: female ratio: 60.5%: 39.4%


Overall, ICD-11 guidelines led to more consistent diagnostic decisions than ICD-10 guidelines.

The proposed changes in the structure and content of the ICD-11 guidelines for Disorders Specifically Associated with Stress, including sections on Essential Features, Differential Diagnosis and Additional Features, provided greater clarity of what was required for a diagnosis than the ICD-10 diagnostic guidelines for equivalent disorders.


Complex PTSD and prolonged grief disorder appear to be useful additions to ICD.

Two new disorders were proposed for the Disorders Specifically Associated with Stress: Complex PTSD and Prolonged Grief Disorder. Complex PTSD is a more severe form of PTSD that adds symptoms of longstanding disruptions in affect regulation, persistent negative beliefs about one’s self or the world, and difficulty sustaining relationships. Prolonged Grief Disorder represents a pathological reaction to the death of a loved one above and beyond a normal grief process. Clinicians were able to clearly recognize and diagnose the essential features of each, and both captured cases that were difficult to diagnose using ICD-10.

However, the results indicated that there were some boundary issues with each. Professionals tended to over-diagnose Complex PTSD on the basis of a severe or prolonged stressor rather than the additional required symptoms. Participants had some difficulty differentiating Prolonged Grief Disorder from normal bereavement. These results prompted refinements of the diagnostic guidelines that help specify those boundaries in a more explicit fashion.


Participant responses led to refinements of the diagnostic guidelines for PTSD.

Two changes proposed to the definition of PTSD for ICD-11 included an explicit requirement of functional impairment (which was absent from ICD-10) and a refinement of the definition of the re-experiencing symptom. Specifically, the new guideline stipulated that the re-experiencing must be felt in the present, as opposed to simply being a memory. Tests of these two changes indicated wording ambiguities in the diagnostic guidelines that clinicians had difficulty interpreting. First, the results of the study highlighted that the new definition of re-experiencing only included cognitive descriptions of the phenomenon, and ignored emotional re-experiencing. Second, the definition of impairment was expanded to include circumstances in which the individual continues to function with greater difficulty and suffering because of the interfering nature of the symptoms. Both clarifications are a direct result of the feedback GCPN members offered through their participation in the study.


Keeley, J. W., Reed, G. M., Roberts, M. C., Evans, S. C., Robles, R., Matsumoto, C., Brewin, C. R., Cloitre, M., Perkonigg, A., Rousseau, C. Gureje, O., Lovell, A. M., Sharan P., & Maercker, A. (2016). Disorders specifically associated with stress: A case-controlled field study for ICD-11 Mental and Behavioural Disorders. International Journal of Clinical and Health Psychology, 16, 109-127. https://doi.org/10.1016/j.ijchp.2015.09.002


Maercker, A., Brewin, C. R., Bryant, R.A., Cloitre, M., van Ommeren, M., Jones, L. M., Humayan, A., Kagee, A., Llosa, A. E., Rousseau, C., Somasundaram, D. J., Souza, R., Suzuki, Y., Weissbecker, I., Wessley, S. C., First, M. B., & Reed, G. M. (2013). Diagnosis and classification of disorders specifically associated with stress: Proposals for ICD-11. World Psychiatry, 12, 198-206. Doi: 10.1002/wps.20057 

Hansen, M., Hyland, P., Armour, C., Shevlin, M., & Elkit, A. (2015). Less is more? Assessing the validity of the ICD-11 model of PTSD across multiple trauma samplesEuropean Journal of Psychotraumatology, 6, 28766. Doi: 10.3402/ejpt.v6.28766

Bryant, R. A. (2012). Grief as a psychiatric disorder. British Journal of Psychiatry, 201, 9-10. Doi: 10.1192/bjp.bp.111.102889