Complex posttraumatic stress disorder (CPTSD) has been a focal point of debate within the trauma field for more than three decades: is it different from posttraumatic stress disorder (PTSD), and what treatments should be used? Highlighting the pervasive, detrimental effects of repeated interpersonal trauma—particularly childhood abuse—on psychological health, proponents of a separate CPTSD diagnosis have argued that an array of problems beyond PTSD symptoms is the rule rather than the exception (Cloitre et al., 2005). Although several established exposure-based PTSD interventions are demonstrably effective (Bisson et al., 2013), many patients do not profit substantially from them (Cuijpers et al., 2024). Insufficient attention devoted to the additional problem domains highlighted by the CPTSD diagnosis, including emotional dysregulation, negative self-concept, and difficulties managing relationships (jointly referred to as disturbances in self-organization [DSO]), is proposed as a potential reason for insufficient treatment benefits. If this is the case, adjusting treatment to the needs of CPTSD patients could contribute to improving treatment outcomes (Karatzias, Murphy, et al., 2019). The use of phase-based interventions where a separate skills training, or stabilization, phase precedes exposure-based interventions is a frequently recommended alternative (Cloitre et al., 2010, 2011; Herman, 1992b). However, the need for additional skills training before exposure has been controversial, with other researchers contesting it by citing the broad positive effects of exposure-based PTSD interventions for patients with childhood abuse histories (McLean & Foa, 2024; Van Minnen et al., 2002)
This study had several related aims. First, we examined the validity and reliability of a self-report measure for CPTSD in a Norwegian context. To that end, we investigated the factor structure of the instrument and potential sources of measurement error in the instrument at large and in its constituent sub-domains. A second aim was to contribute to the ongoing treatment debate regarding CPTSD by comparing the three proposed and frequently offered treatment options. Despite the attention that CPTSD has gathered, treatment studies involving patients diagnosed with CPTSD are scarce. Thus, we recruited patients in whom a formal CPTSD diagnosis related to childhood traumatization could be established. We investigated whether a phase-based treatment designed for this patient group would improve treatment outcomes compared to an exposure intervention developed for a broader PTSD patient group or to skills training alone (i.e., the first phase of phase-based treatment but without the second exposure phase). Third, we examined whether the effects of these three treatment approaches were primarily specific to their targeted symptoms or if the effects were broader and included symptoms not specifically targeted by each intervention. The former would be an argument for combining different interventions, each tailored to the two problem domains in CPTSD (i.e., PTSD and DSO), while the latter would imply that a single intervention could suffice. Ultimately, we aimed to inform clinicians and patients about the effects of these different treatment alternatives and thereby support the implementation and use of effective strategies to treat CPTSD.
The study was conducted in a publicly funded residential clinic. Among other interventions, the clinic offers various treatment programs to patients diagnosed with PTSD, CPTSD, and dissociative disorders. Patients are commonly referred to the clinic because they have previously failed to respond to outpatient treatment.
Paper I is devoted to the first study aim. A sample of patients seeking trauma treatment reported symptoms using a self-report instrument, the International Trauma Questionnaire (ITQ), designed to measure ICD-11 PTSD and CPTSD. Overall, our findings support the reliability of the ITQ scores. However, we identified the problematic influences of error related to the measurement of affective dysregulation, one of the DSO sub-domains. Closer examination revealed that the measurement of affective hyperactivation (e.g., difficulties calming down when upset) especially returned concerning error rates, suggesting that more items could be added to the instrument to strengthen the reliability of the scores. The theoretical factor structure of the instrument follows the ICD-11 diagnostic classification of PTSD and CPTSD and shows an acceptable fit with the data. However, examinations of the factor structure in a short version of the instrument did not converge, again indicating that reducing the number of items could be problematic.
Paper II addresses the second study aim. We conducted a randomized controlled trial (RCT) to directly compare the effects of three treatment alternatives for CPTSD. Contesting our main hypothesis, phase-based treatment was not associated with improved outcomes compared to exposure or skills training for patients diagnosed with ICD-11 CPTSD. Contrary to assumptions, the shorter exposure intervention outperformed the phase-based intervention regarding PTSD symptom reductions, and we found no differences regarding CPTSD symptoms. Overall, the results suggest that patients with CPTSD profit from a single-phase exposure treatment, which is an established intervention for PTSD.
Paper III pursued the third study aim, where frequent measurements of self-reported CPTSD symptoms during treatment were used to model the trajectories of symptom change. By examining the change trajectories for PTSD and DSO symptoms separately, we compared how symptoms developed in the three treatments. The findings supported the hypothesis that PTSD symptom reductions would be steeper during exposure than during skills training but did not support the opposite expected superiority of skills training for the rate of DSO symptom change. The latter finding was surprising given that the skills training program specifically addresses DSO, whereas the exposure treatment primarily targets PTSD. The results indicate the advantage of using exposure for reducing PTSD symptoms, whereas DSO symptoms are reduced both by exposure and skills training.