Understanding Complex PTSD Diagnosis: Evolution and ICD-11 Criteria

Complex Posttraumatic Stress Disorder (CPTSD) emerged as a concept to better describe the lasting impacts of prolonged, early trauma, such as childhood abuse. While the discussion continues regarding whether CPTSD is a distinct condition from PTSD, its definition has evolved, particularly with the International Classification of Diseases-11th Revision (ICD-11) formally recognizing it. This article aims to clarify the complexities of Complex Ptsd Diagnosis, tracing its historical development, defining what it is and isn’t, and contrasting it with PTSD.

Early Concepts of Complex PTSD

Following the introduction of Posttraumatic Stress Disorder (PTSD) in the Diagnostic and Statistical Manual 3rd Revision (DSM-III) in 1980, clinicians and researchers observed that the existing PTSD diagnosis didn’t fully encompass the wide range of difficulties experienced by individuals exposed to chronic interpersonal trauma (1-3). This observation led to the initial conceptualization of complex PTSD (CPTSD; 1, 2), and its proposed operationalization as Disorders of Extreme Stress Not Otherwise Specified (DESNOS) for the DSM-IV (3). CPTSD was understood to be a more frequent outcome of repeated, long-lasting interpersonal trauma, especially occurring early in life, such as childhood sexual abuse by a family member or experiences like being a prisoner of war. The definition of “complex trauma” varied, but the resulting symptoms were seen as extending beyond the core PTSD symptoms of intrusion, avoidance, and hyperarousal defined in the DSM-III. These additional challenges included difficulties in managing emotions and impulses, memory problems or dissociation, altered self-perception (like guilt, shame, and feeling permanently damaged), difficulties in relationships (such as trust issues or revictimization), physical symptoms without medical explanation (somatization), and changes in belief systems (like despair or loss of faith).

Early definitions of CPTSD, therefore, linked specific types of trauma to a broader spectrum of symptoms and personality changes. In preparation for the DSM-IV, field trials incorporated symptom checklists to assess DESNOS symptoms alongside PTSD symptoms, aiming to capture this expanded understanding of trauma’s impact (for details on these symptoms, see van der Kolk et al., 2005 (4)).

DSM-IV and DSM-5 Perspectives on Complex PTSD Diagnosis

Ultimately, DESNOS was not included as a formal diagnosis in the DSM-IV due to key considerations:

1. DESNOS symptoms were rarely seen without a co-occurring PTSD diagnosis (4), suggesting they might not represent a distinct condition but rather a more severe or complex presentation of PTSD.
2. The DSM-IV revision process prioritized empirical evidence and a cautious approach to diagnostic changes, recognizing the significant impact of diagnostic classifications on clinical practice and research (5). Consequently, DESNOS symptoms were included as “associated features” of DSM-IV PTSD, rather than forming a separate diagnostic category.

In the subsequent DSM-5, the PTSD diagnosis was revised and broadened, incorporating some symptoms previously associated with CPTSD (5). Symptoms like excessive self-blame, persistent negative emotions, irritability/aggression, and impulsive or self-destructive behaviors were integrated into the PTSD diagnostic criteria itself. This decision was driven by several factors:

1. The high bar for diagnostic changes remained in place. At the time of DSM-5 development, the definition of CPTSD was still evolving, and its construct validity and clinical utility were not yet deemed sufficient for a separate DSM diagnosis (5).
2. A broader approach to symptom inclusion was adopted to ensure that all clinically relevant symptoms of PTSD were captured, even if they overlapped with other disorders (e.g., insomnia, irritability; 5). This was seen as enhancing clinical utility by providing a more comprehensive symptom profile relevant to diverse clinical presentations.
3. It was argued that DESNOS symptoms often overlapped with the core PTSD symptom constellation or could be addressed through a diagnosis of PTSD alongside Borderline Personality Disorder. This relationship continues to be investigated (for reviews, see Resick et al., 2012 (6); Atkinson et al., 2024 (7)).

Therefore, the current DSM-5 PTSD diagnosis has expanded to encompass many symptoms initially considered part of CPTSD (and DESNOS). Furthermore, the introduction of a dissociative subtype of PTSD in DSM-5 was intended to capture aspects of the CPTSD construct (5).

ICD-10 and ICD-11 Framework for Complex PTSD Diagnosis

In contrast to the DSM approach, the ICD-10 included “Enduring personality change after catastrophic experience” (EPCACE), a personality disorder requiring an extremely stressful event capable of causing lasting personality changes (e.g., withdrawal, distrust, hopelessness) regardless of individual vulnerability. EPCACE was intended as a form of complex PTSD, but it received limited attention in research and clinical practice. However, EPCACE served as the foundation for the development of CPTSD in the ICD-11 (8).

The ICD-11 adopted a different strategy than DSM-5, prioritizing “clinical utility,” particularly for non-mental health professionals and settings with limited resources (9). In the ICD-11 context, clinical utility emphasized diagnoses with fewer symptoms, ease of use by non-specialists, and relevance to clinical decision-making. ICD-11 established complex PTSD as a distinct diagnosis from PTSD based on:

1. Psychometric evidence indicating that PTSD and CPTSD are distinguishable conditions (10, 11), although some argue the differentiation is more about severity than distinct symptom types (12).
2. Evidence suggesting CPTSD is more strongly associated with early, repeated interpersonal trauma compared to PTSD (4), and linked to greater functional impairment (11).
3. Feedback from an international World Health Organization survey of clinicians, which highlighted CPTSD as the most requested new diagnosis for inclusion (13).

The ICD-11 working group focused on what were considered the core fear-related symptoms of PTSD: re-experiencing trauma in the present, avoidance of trauma-related stimuli, and a heightened sense of threat (based on Brewin et al., 2009 (14)). Given that most individuals with DESNOS in DSM field trials also met criteria for PTSD, the ICD-11 diagnostic criteria for complex PTSD diagnosis require meeting the criteria for PTSD in addition to “disturbances in self-organization” (DSO). DSO is characterized by significant difficulties in three areas: affect regulation, self-concept, and relationships. (See Table 1 below for a summary of DSO symptoms and refer to the full ICD-11 criteria for CPTSD.)

Table 1. ICD-11 Symptoms of DSO for Complex PTSD Diagnosis (15)

Domain	Example Symptoms
Affect regulation	– Extreme emotional reactivity – Self-destructiveness – Dissociation
Self-concept	– Feeling deeply worthless or defeated – Feeling extensively guilty and ashamed about the trauma (e.g., “I should have left”)
Relationship functioning	– Significant difficulties with sustained emotional intimacy

These DSO symptoms were chosen as they were prominent in the DSM-IV field trials related to EPCACE symptom domains and were considered by experts to be strongly linked to functional impairment (11, 16). This ICD-11 criteria set is more concise than the DESNOS criteria tested in DSM-IV trials, and it omits some symptoms (e.g., somatization). While dissociation is present in both PTSD and CPTSD (e.g., flashbacks, affect dysregulation), it’s not considered a core, essential element in the ICD-11 CPTSD definition as it was in earlier formulations. Recent research suggests that there may be subgroups within ICD-11 CPTSD, including those with and without significant dissociation (17).

Notably, ICD-11 complex PTSD diagnosis does not require a specific type of trauma, differentiating it from earlier CPTSD constructs that emphasized particular trauma histories. This shift reflects evidence that while complex traumas are more frequently associated with CPTSD symptoms and vice versa, the correlation is not perfect (i.e., CPTSD can occur after single traumas, and PTSD alone can occur after prolonged early trauma; 10, 11). Thus, ICD-11 views prolonged, complex traumas as risk factors for complex PTSD, but not as mandatory preconditions for diagnosis.

Prevalence of Complex PTSD

Prevalence rates for PTSD and CPTSD vary depending on whether DSM-5 or ICD-11 definitions are used. Generally, ICD-11 PTSD prevalence rates appear lower than DSM-5 PTSD rates (11). However, when combining ICD-11 PTSD and CPTSD prevalence, a U.S. study of 1,839 adults found an overall rate of 7.2% (3.4% PTSD and 3.8% CPTSD; 18), which is comparable to the 6% prevalence of DSM-5 PTSD in the U.S.

Summary: Evolving Understanding of Complex PTSD Diagnosis

The recognition of long-term impacts of prolonged, complex trauma has been evolving. The definition of complex PTSD has changed over time, making comparisons across research periods complex. Currently, two main diagnostic frameworks address complex trauma responses differently: DSM-5 integrates some CPTSD-related symptoms into the PTSD symptom set, while ICD-11 recognizes CPTSD as a distinct, co-occurring diagnosis alongside PTSD. The ICD-11‘s clear operationalization of CPTSD, including specific criteria and standardized assessment tools, is a significant advancement. This distinction allows for future research to investigate whether different treatment approaches are indeed needed for these distinct diagnoses and to further refine our understanding of complex PTSD diagnosis. For more information on assessment, treatment, and clinical utility, see Complex PTSD: Assessment and Treatment.

References

1. Herman, J. L. (1992). Complex PTSD: A syndrome in survivors of prolonged and repeated trauma. Journal of Traumatic Stress, 5(3), 377-391. https://doi.org/10.1002/jts.249005305
2. van der Kolk, B. A., Pelcovitz, D., Roth, S., Mandel, R. S., McFarlane, A., & Herman, J. (1996). Dissociation, affect dysregulation and somatization: The complex nature of adaptation to trauma. American Journal of Psychiatry, 153(7), 83-93. https://doi.org/10.117/ajp.153.7.83
3. Pelcovitz, D., van der Kolk, B., Roth, S., Mandel, F., Kaplan, S., & Resick, P. (1997). Development of a criteria set and a Structured Interview for Disorders of Extreme Stress (SIDES). Journal of Traumatic Stress, 10(1), 3-16. https://doi.org/10.1002/jts.2490100103
4. van der Kolk, B. A., Roth, S., Pelcovitz, D., Sunday, S., & Spinazzola, J. (2005). Disorders of extreme stress: The empirical foundation of a complex adaptation to trauma. Journal of Traumatic Stress, 18(5), 389-399. https://doi.org/10.1002/jts.20047
5. Friedman, M. J. (2013). Finalizing PTSD in DSM-5: Getting here from there and where to go next. Journal of Traumatic Stress, 26(5), 548-556. https://doi.org/10.1002/jts21840
6. Resick, P. A., Bovin, M. J., Calloway, A. L., Dick, A. M., King, M. W., Mitchell, K. S., Suvak, M. K., Wells, S. Y., Wiltsey Stirman, S., & Wolf, E. J. (2012). A critical evaluation of the complex PTSD literature: Implications for DSM-5. Journal of Traumatic Stress, 25(3), 241-251. https://doi.org/10.1002/jts.21699
7. Atkinson, J. R., Kristinsdottir, K. H., Lee, T., & Freestone, M. C. (2024). Comparing the symptom presentation similarities and differences of complex posttraumatic stress disorder and borderline personality disorder: A systematic review. Personality Disorders: Theory, Research, and Treatment. Advance online publication. https://doi.org/10.1037/per0000664
8. Maercker, A. (2021). Development of the new CPTSD diagnosis for ICD-11. Borderline Personality Disorder and Emotion Dysregulation, 8(7), 1-4. https://doi.org/10.1186/s40479-021-00148-8
9. Reed, G. M. (2010). Toward ICD-11: Improving the clinical utility of WHO’s International Classification of mental disorders. Professional Psychology: Research and Practice, 41(6), 457-464. https://doi.org/10.1037/a0021701
10. Cloitre, M., Garvert, D. W., Brewin, C. R., Bryant, R. A., & Maercker, A. (2013). Evidence for proposed ICD-11 PTSD and complex PTSD: A latent profile analysis. European Journal of Psychotraumatology, 4(1), 20706. https://doi.org/10.3402/ejpt.v4i0.20706
11. Brewin, C. R., Cloitre, M., Hyland, P., Shevlin, M., Maercker, A., Bryant, R. A., Humayun, A., Jones, L. M., Kagee, A., Rousseau, C., Somasundaram, D., Suzuki, Y., Wessely, S., van Ommeren, M., & Reed, G. M. (2017). A review of current evidence regarding the ICD-11 proposals for diagnosing PTSD and complex PTSD. Clinical Psychology Review, 58, 1-15. https://doi.org/10.1016/j.cpr.2017.09.001
12. Wolf, E. J., Miller, M. W., Kilpatrick, D., Resnick, H. S., Badour, C. L., Marx, B. P., Keane, T. M., Rosen, R. C., & Friedman, M. J. (2015). ICD-11 complex PTSD in U.S. national and Veteran samples: Prevalence and structural associations with PTSD. Clinical Psychological Science, 3(2), 215-229. https://doi.org/10.1177/2167702614545480
13. Robles, R., Fresán, A., Evans, S. C., Lovell, A. M., Medina-Mora, M. E., Maj, M., & Reed, G. M. (2014). Problematic, absent and stigmatizing diagnoses in current mental disorders classifications: Results from the WHO-WPA and WHO-IUPsyS Global Surveys. International Journal of Clinical and Health Psychology, 14(3), 165-177. https://doi.org/10.1016/j.ijchp.2014.03.003
14. Brewin, C. R., Lanius, R. A., Novac, A., Schnyder, U., & Galea, S. (2009). Reformulating PTSD for DSMâ€V: Life after criterion A. Journal of Traumatic Stress, 22(5), 366-373. https://doi.org/10.1002/jts.204433
15. World Health Organization. (2022). ICD-11: International classification of diseases (11th revision). https://icd.who.int/
16. Cloitre, M., Courtois, C. A., Charuvastra, A., Carapezza, R., Stolbach, B. C., & Green, B. L. (2011). Treatment of complex PTSD: Results of the ISTSS expert clinician survey on best practices. Journal of Traumatic Stress, 24(6), 615-627. https://doi.org/10.1002/jts.20697
17. Hyland, P., Hamer, R., Fox, R., Vallières, F., Karatzias, T., Shevlin, M., & Cloitre, M. (2024). Is dissociation a fundamental component of ICD-11 Complex Posttraumatic Stress Disorder? Journal of Trauma & Dissociation, 25(1), 45-61. https://doi.org/10.1080/15299732.2023.2231928
18. Cloitre, M., Hyland, P., Bisson, J. I., Brewin, C. R., Roberts, N. P., Karatzias, T., & Shevlin, M. (2019). ICD-11 posttraumatic stress disorder and complex posttraumatic stress disorder in the United States: A population-based study. Journal of Traumatic Stress, 32(6), 833-842. https://doi.org/10.1002/jts.22454

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