Implementation of evidence-based treatment for PTSD in Norway: clinical outcomes and impact of probable complex PTSD

Background: Posttraumatic stress disorder (PTSD) is a long-lasting and debilitating psychological disorder that affects a large portion of the population. Treatments such as Cognitive therapy for PTSD (CT-PTSD) and Eye movement desensitization and reprocessing (EMDR) have been shown to be effective and cost-efficient in clinical trials, but uptake and evidence of positive outcomes in real-world clinical services are limited. Implementation efforts have been hampered by providers' concerns about the feasibility of trauma-focused treatments in more complex presentations (i.e. Complex PTSD). Objective: To evaluate the effectiveness of CT-PTSD and EMDR in a real-world setting, as implemented in Norwegian outpatient mental health clinics for adults, and investigate the impact of probable Complex PTSD status on treatment outcomes. Methods: Clinicians from 15 different outpatient clinics received training and supervision in EMDR or CT-PTSD as part of a national implementation project. 104 clinicians recruited and treated 196 participants with PTSD. Symptoms of PTSD, depression and anxiety were assessed session-by-session and used to estimate pre-post effect sizes. Mixed-models were employed to investigate the impact of complex PTSD. Results: Both EMDR and CT-PTSD were associated with significant reductions in PTSD symptoms, with large effect sizes. Probable Complex PTSD was associated with higher levels of symptoms before and after treatment but did not significantly impact the effectiveness of treatment. Conclusion: The use of evidence-based treatments for PTSD in routine clinical service is associated with good treatment outcomes, also for patients with Complex PTSD.