Efficacy of an internet-based guided trauma-focused intervention in reducing ICD-11 posttraumatic stress disorder symptoms : study protocol of a randomized controlled trial

Background
Posttraumatic stress disorder (PTSD) is a common mental disorder. However, many cases of PTSD remain untreated because of limited healthcare resources and other treatment-seeking barriers. Effective internet-based interventions could help to improve access to PTSD treatments. Therefore, the main objective of the planned randomized controlled trial is to evaluate the efficacy of the Lithuanian version of the guided internet-based self-help programme (Spring) in reducing ICD-11 PTSD symptoms.

Methods
The planned sample size is 50 participants exposed to different traumatic experiences. Participants eligible for the study will be randomized into two study groups: the immediate treatment group and the delayed treatment control group. Both groups will receive guided trauma-focused ICBT intervention, but the delayed treatment group will receive access to the programme five months after randomization. The International Trauma Interview (ITI) will be used for the assessment of ICD-11 PTSD symptoms at pre-treatment, post-treatment, and at a 3-month follow-up. Changes in disturbances in self-organization, depression and anxiety levels, as well as posttraumatic cognitions and trauma-related shame, will also be evaluated. In addition, associations between changes in symptoms of PTSD and readiness for treatment, treatment expectations and working alliance will be explored. Changes in treatment outcomes will be evaluated using multiple Latent Change Models.

Discussion
This study is expected to contribute to valuable knowledge on the efficacy of internet-based interventions for posttraumatic stress disorder.

Trial registration
ClinicalTrials.gov NCT06475716. Registered on 25 June 2024.