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The inclusion of a complex PTSD (CPTSD) diagnosis in the World Health Organization’s (WHO) International Classification of Diseases (ICD) Revision 11 represents a milestone for those concerned with complex trauma. Survivors, clinicians, researchers, and other professionals have been advocating for this diagnosis for many years.

Complex PTSD was first proposed by Herman (1992) 30 years ago:

The existing diagnostic criteria for [PTSD] are derived mainly from survivors of circumscribed traumatic events. They are based on prototypes of combat, disaster, and rape. In survivors of prolonged, repeated trauma, the symptom picture is often more complex.... I propose to call it complex post-traumatic stress disorder. (p. 119)

Although many professionals endorsed  CPTSD as a credible diagnosis (van der Kolk, 2019), it has been the subject of ongoing debate (Herman, 2012; Resnick et al., 2012a; Resnick et al., 2012b; Weiss, 2012). Despite a great deal of support, it was not included in the fourth and fifth editions of the American Psychiatric Association’s (APA) Diagnostic and Statistical Manual of Mental Disorders (DSM; Herman in Ford & Courtois, 2020, p. xi; van der Kolk, 2019).

However, “though relegated to the associated features of PTSD in DSM-IV, the concept of complex PTSD nevertheless took on a life of its own” (Herman in Ford & Courtois, 2020, p. xii). Herman attributes this to a “vast body of clinical observation” of what survivors of protracted traumatic stressors were experiencing; that is, additional symptoms distinct from those of PTSD.

Many of our SIG members as well as other determined researchers and professionals have worked tirelessly for decades to confirm the credibility and efficacy of CPTSD as the “distinct entity” Herman (1992, 1997, 2012) proposed it to be. While the APA still has not accepted the diagnosis, the inclusion of CPTSD in the ICD-11 is facilitating expansive research, dialogue, and utility in the area of complex trauma for clinicians, researchers, survivors, and other professionals worldwide in meaningful and important ways. The diagnostic criteria in the ICD-11 (2022) reads as follows:  

All diagnostic requirements for PTSD are met. In addition, CPTSD is characterised by severe and persistent 1) problems in affect regulation; 2) beliefs about oneself as diminished, defeated or worthless, accompanied by feelings of shame, guilt or failure related to the traumatic event[s]; and 3) difficulties in sustaining relationships and in feeling close to others. These symptoms cause significant impairment in personal, family, social, educational, occupational or other important areas of functioning.

CPTSD is a response by children and/or adults to various types of ongoing and overwhelming complex trauma. These types may include: relational or interpersonal—occurs when a child or adult is caught in an abusive/neglectful relationship with someone in a position of perceived or real authority/power (e.g., family member, religious leader, coach, employer); identity—traumatization of a person/group based on identifiable characteristics (e.g., race, gender); community—traumatization based on membership in a particular group (e.g., political, religious, sexual orientation); institutional—trauma caused by the actions/lack of action on the part of an institution (e.g., church, police, justice, educational); and impersonal—random, lasting events (e.g., natural disasters, pandemics, chronic illness; Courtois, 2014; Ford & Courtois, 2020).

The ISTSS Complex Trauma SIG seeks to bring together researchers, clinicians, social and public health professionals, advocates, and those with lived experience of complex traumatic stress. Our mission is to galvanize SIG members and other organizations to participate in projects and research that increase a global understanding of these various types of complex trauma as stressors as well as the sequalae of the associated symptoms of CPTSD. We strive to foster advocacy and organize for improvements in research, prevention/intervention, diagnosis, treatment, services, and life outcomes for individuals impacted by complex trauma.

We believe this is best achieved by bringing together diverse voices and working collaboratively. ISTSS members who are professionals from related fields (e.g., mental health, medicine, justice, social work, education), researchers, students, and survivors are most welcome to join. We hold monthly Zoom meetings, which we announce through the SIG listserv. We publish a newsletter, “Complex Trauma Perspectives,” and welcome submissions representing diverse perspectives about complex trauma. Our SIG has also produced bibliographies identifying both complex trauma and ICD-11 CPTSD research. These are updated as additional research is published. Copies of these bibliographies and our newsletter may be found on our webpage.

The WHO’s recognition of CPTSD is a watershed moment for those of us involved with complex trauma. The CPTSD diagnosis will help foster a much wider and deeper understanding of what complex trauma is and bodes well in terms of effective assessment, treatment, and services. Thank you to Judith Herman and everyone who worked to get this diagnosis accepted! It may have taken 30 years, but the day is finally here and we look forward to new horizons in the area of complex trauma. 

How to Join This SIG 

If you are interested in joining the Complex Trauma ‎SIG: 

  1. Log in and go to your ISTSS member profile
  1. Go to the Listservs/Communities tab and select the SIG(s) you want to join from the dropdown. 
  1. Scroll down and click “next,” then “save changes.” 


Courtois, C. (2014). It’s not you, it’s what happened to you: Complex trauma and treatment. Telemachus Press.

Ford, J. & Courtois, C. (Eds.) (2020). Treating Complex Traumatic Stress Disorders in adults: Scientific foundations and therapeutic models. (2nd ed.). New York, NY: Guilford Press.
Herman, J. (1992, 1997, 2015). Trauma and recovery: The aftermath of violence - from domestic abuse to political terror. New York: Basic Books.
Herman, J. (2012). CPTSD is a distinct entity: Comment on Resick et al. (2012). Journal of Traumatic Stress, 25(3), 256-257.
Resick, P. Bovin, M., Calloway, A., Dick, A., King, M., Mitchell, K., Suvak, M., Wells, S., Stirman, S., & Wolf, E. (2012). A critical evaluation of the Complex PTSD literature: Implications for DSM-5. Journal of Traumatic Stress, 25(3), 241-251.
Resick, P., Wolf, E., Wiltsey Stirman, S., Wells, S., Suvak, M., Mitchell, K., King, M., & Bovin, M. (2012). Advocacy through science: Reply to comments on Resick et al. (2012). Journal of Traumatic Stress, 25(3), 260-263.
van der Kolk, B. (2019). The politics of mental health. Psychotherapy Networker.
Weiss, D. S. (2012). Introduction to the special feature on Complex PTSD. Journal of Traumatic Stress, 25(3), 239-240.
World Health Organization. (2022).  ICD-11: International Classification of Diseases 11th Revision.

About the Author

Lori Herod, EdD is Co-Chair of the ISTSS Complex Trauma Special Interest Group. She is a retired professor of Adult Education who is a survivor of relational trauma and suffers from Complex PTSD. She founded an information website and discussion forum for survivors of relational trauma. The site has grown to over 10,000 members from 56 countries since 2014.

As the spouse of a Canadian military officer, Lori has lived all across Canada. In addition to teaching, she has worked and volunteered in many sectors including violence against women in Ontario, adult literacy in Ontario and Manitoba, restorative justice in Alberta, and recently program development with the Canadian Centre for Inquiry.