PTSD: National Center for PTSD

Complex PTSD: History and Definitions

Sadie E. Larsen, PhD

Complex posttraumatic stress disorder (CPTSD) was proposed shortly after the introduction of PTSD to capture the long-term consequences of prolonged, early trauma, such as child sexual abuse. There is continued debate about whether CPTSD is its own disorder or part of PTSD. Adding to the discourse is that the definition of CPTSD has shifted over time, most recently being defined by the International Classification of Diseases-11th Revision (ICD-11). In this article, we clarify what CPTSD is and is not, how it has changed over time, and how it relates to PTSD.

Early Proposals

After the diagnosis of PTSD was first included in the Diagnostic and Statistical Manual 3rd Revision (DSM-III) in 1980, some clinicians and researchers began to argue that the diagnosis did not fully capture the sequelae of trauma, especially for individuals who had experienced prolonged interpersonal trauma (1-3). This led to the introduction of the first conceptual formulation of complex PTSD (CPTSD; 1,2) and its operationalization as a DSM-IV disorder, Disorders of Extreme Stress Not Otherwise Specified (DESNOS; 3). As compared to PTSD, CPTSD was proposed to be more common following repeated, prolonged, interpersonal trauma, especially early in life. Examples include childhood sexual abuse by a family member or being a prisoner of war, but what "counts" as "complex trauma" varied somewhat across investigators. The symptoms related to such experiences were understood to constitute a range of sequelae going beyond the intrusive symptoms, avoidance, and hyperarousal that constituted DSM-III-defined PTSD. These were argued to include difficulties with affect and impulse regulation, amnesia or dissociation, alterations in self-perception (e.g., guilt, shame, a sense of being permanently damaged), alterations in relations with others (e.g., inability to trust or revictimization), somatization, and alterations in systems of meaning (e.g., despair or loss of previously sustaining beliefs).

Thus, early definitions of CPTSD identified both a type of trauma and a set of symptoms and characterological changes that emerged from those trauma types. In response, the field trials conducted to inform the DSM-IV included a set of symptoms meant to assess DESNOS symptoms in addition to PTSD symptoms (for the specific symptoms included in the field trials, see van der Kolk et al., 2005 (4)).

DSM-IV and DSM-5 Approach to CPTSD

Ultimately DESNOS was not included in the DSM-IV, because:

1. The symptoms of DESNOS rarely occurred in the absence of a diagnosis of PTSD (4) and so were not judged to constitute a separate diagnosis.
2. The DSM-IV Work Group took the approach of setting a high empirical bar for making any changes, given that any changes to diagnoses could have important consequences for both clinicians and scientists (5). Instead, the symptoms of DESNOS were included as "associated descriptive features" of DSM-IV PTSD rather than a separate diagnosis.

In the DSM-5, the diagnosis of PTSD was modified and expanded to capture some of the symptoms of CPTSD (5), by adding symptoms such as erroneous self-blame, persistent negative mood, irritation/aggression, and impulsive or self-destructive behavior, as part of the PTSD diagnosis itself. This approach was taken because:

1. Again, there was a high empirical bar for making any changes. As of the development of the DSM-5, the definition of CPTSD was still in flux, meaning that construct validity and clinical utility had not yet met the high bar the committee required for a change to the DSM (5).
2. A broader versus narrower approach was taken to symptoms, so that all important symptoms of PTSD continued to be included, even if they might overlap with other disorders (e.g., insomnia, irritability; 5). This was argued to have greater clinical utility by providing clinicians with a range of symptoms that would cover most typical clinical presentations.
3. Authors argued at the time that DESNOS symptoms were often part of the core constellation of PTSD symptoms or could be captured by a diagnosis of PTSD in combination with borderline personality disorder (this question is still under study; for earlier and more recent reviews, see Resick et al., 2012 (6); Atkinson et al., 2024 (7)).

This means that in practice, the current diagnosis of DSM-5 PTSD has evolved to include more of the symptoms traditionally thought of as part of CPTSD (and DESNOS). Additionally, a dissociative subtype of PTSD was created, which was argued to map onto some of the construct of CPTSD (5).

ICD-10 and ICD-11 Approach to CPTSD

In addition to including PTSD, the ICD-10 included a personality disorder called "Enduring personality change after catastrophic experience" (EPCACE), which required an event so stressful that it would lead to enduring personality change (e.g., withdrawal, distrust, hopelessness) regardless of personal vulnerability. EPCACE was intended to represent a form of complex PTSD, but it did not receive significant research or clinical attention. In the ICD-11, EPCACE served as the basis for the development of CPTSD (8).

The ICD-11 took a different approach than DSM-5, informed by a desire for the text to have "clinical utility," including for non-mental health providers and others in low-resource settings (9). For ICD-11, clinical utility meant that diagnoses were preferred to have fewer symptoms, be easy to use by non-specialists, and reflect categories that clinicians find understandable and useful in shaping care. In ICD-11, complex PTSD was established as a separate diagnosis from PTSD because of:

1. Psychometric evidence that PTSD and CPTSD can be differentiated (10,11), although some have argued that they are differentiated more by severity than type (12).
2. Evidence that, compared to PTSD, complex PTSD is more often related to early repeated interpersonal trauma (4) and to more significant functional impairment (11).
3. Evidence from an international World Health Organization survey of clinicians that CPTSD was the most requested new diagnosis for inclusion (13).

The ICD-11 stress disorders working group chose the symptoms of PTSD argued to be the essential fear-related components of PTSD: reliving in the here and now, avoidance of trauma material, and a heightened sense of current threat (based on work by Brewin et al., 2009 (14)). Because most people with DESNOS in the DSM field trials also had PTSD, complex PTSD can be diagnosed when people meet criteria for PTSD, in addition to "disturbances in self-organization" (DSO) defined as significant difficulties in affect regulation, self-concept, and relationships. (See Table 1 below for a summary of DSO symptoms; view the full criteria for ICD-11 CPTSD.

Table 1. ICD-11 Symptoms of DSO (15)

These DSO symptoms were chosen because they were the most frequent symptoms in the DSM-IV field trials that mapped onto EPCACE symptoms domains, and they were believed to be commonly related to higher levels of functional impairment in an expert survey (11,16). This is a much briefer set of criteria than the DESNOS that was tested in the DSM-IV field trials, and with fewer core symptoms (e.g., somatization is not included). Although some symptoms of PTSD and CPTSD involve dissociation (e.g., flashbacks, affect regulation), it is not considered an essential element as it was in earlier formulations (recent work suggests that there may be distinct groups of people with ICD-11 CPTSD: both with and without significant dissociation; 17).

A specific type of trauma is not required for an ICD-11 CPTSD diagnosis, thereby differentiating the ICD-11 conceptualization of CPTSD from earlier constructs of CPTSD which were predicated on these symptoms stemming from a particular type of trauma. This change was due to evidence that although complex traumas are more often related to the symptoms of complex PTSD, and vice versa, they are not perfectly correlated (i.e., a smaller portion of people experience CPTSD after a single trauma or experience PTSD alone after prolonged early trauma; 10,11). For this reason, the ICD-11 conceptualizes prolonged, complex traumas as risk factors for complex PTSD, but not as necessary to the diagnosis.

Prevalence

Given these changes to the conceptualization of PTSD and CPTSD, prevalence of PTSD differs depending on whether the DSM-5 or ICD-11 definitions are used. Generally, prevalence rates of ICD-11 PTSD appear to be lower than DSM-5 PTSD (11). But, when adding together ICD-11 PTSD and CPTSD, the overall prevalence rate in a U.S. sample of 1,839 adults was 7.2% (3.4% PTSD and 3.8% CPTSD; 18), which is similar to the 6% prevalence of DSM-5 PTSD in the U.S.

Summary

It has long been recognized that prolonged, complicated trauma can affect people for years. The working definition of complex PTSD has evolved in the field over time, making it somewhat challenging to compare earlier to later research. Currently the field has two working definitions of PTSD that incorporate complex responses to trauma in two different ways: as part of the symptom constellation of PTSD (in the DSM-5) or as a separate, paired diagnosis (in the ICD-11). Having a clear operationalization of CPTSD (including a definition and standardized measures) has been a major advance in the field that should allow for future treatment studies to examine whether, in fact, different treatment approaches are needed for different diagnoses. For more information about 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 DSM-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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