The American Psychological Association has jointly produced a professional practice guideline with the International Society for the Study of Trauma and Dissociation focusing on adults with complex trauma histories. Complex PTSD is now included in the 11th edition of the International Classification of Diseases (ICD-11) of the World Health Organization, and involves exposure to events that overwhelm the ability to cope, typically involving direct interpersonal and emotional threats.
Diagnosis and Symptoms
Beyond the original three PTSD criteria—reexperiencing trauma, numbing of trauma reminders, and physiological hyperarousal—complex PTSD requires three additional criteria under “disturbances in self-regulation”: difficulties in identifying and regulating emotions, negative self-concept and low self-worth, and problems maintaining or forming relationships. Christine Courtois, PhD, ABPP, a counseling psychologist who chaired the complex trauma guideline development panel, notes that trauma occurring earlier in development or across multiple developmental phases often presents with more complex symptoms, including dissociation as a defense mechanism. “When you’re treating complex PTSD, you have more things to treat,” Courtois explained, as many of these individuals lack foundational emotional regulation skills from childhood that must be developed during therapy.
The HISTORY Framework
The guideline employs an acronym—HISTORY—to guide clinicians in treatment. The approach emphasizes a humanistic stance that acknowledges past betrayals by trusted figures, integrative solutions using personalized and evidence-informed treatments including mindfulness or yoga, and careful sequencing with attention to patient readiness and safety. The framework also incorporates timeline considerations reflecting the developmental context of trauma, outcomes assessment addressing all patient problems, the therapeutic relationship as foundational, and exploring existential questions to help patients reappraise trauma and recognize they were not to blame.
Patient-Centered Treatment
According to Paul Frewen, PhD, a clinical psychologist at Western University in Ontario who cochaired the guideline development, “there is no ‘one size fits all’” in complex trauma treatment. The approach requires flexibility to meet each person where they are, recognizing that symptoms vary significantly across age groups and life stages. The therapeutic relationship—being responsive, reliable, trustworthy, and consistent—provides patients with a different relational experience that can become a template for their outside relationships.
This article is an AI-assisted summary. All facts and figures are drawn from the original report: https://www.apa.org/monitor/2025/07-08/guidelines-treating-ptsd-trauma