Study protocol of a randomized controlled superiority trial of Huddinge Online Prolonged Exposure therapy (HOPE) for adults with posttraumatic stress disorder.

BACKGROUND: Cognitive behavioral therapy (CBT) is considered a first-line treatment for posttraumatic stress disorder (PTSD) but is rarely available in regular care. Action is clearly needed to increase treatment availability. A possible solution to improve access to treatment would be the use of remotely delivered digital intervention. Internet-delivered CBT may also carry several other advantages compared to traditional psychological treatments (e.g., less therapist time per patient, bridging geographical distances between therapist and patient, and provision of a standardized intervention). In a pilot study conducted within a psychiatric outpatient setting, a digital therapist-guided prolonged exposure program (Huddinge Online Prolonged Exposure; HOPE) demonstrated preliminary effectiveness, patient acceptability, and feasibility. This project will build upon these findings and evaluate whether HOPE is effective in reducing PTSD symptoms.

METHOD: The study is a randomized controlled superiority trial, with assessors masked to treatment allocation. Two hundred eighty-six participants will be randomly allocated to receive either 10 weeks of HOPE or an active control condition (therapist-guided internet-delivered psychoeducation, relaxation, and support). The primary outcome is the severity of symptoms of PTSD for the last month measured by the clinician-administered PTSD scale for DSM-5 (CAPS-5). Secondary outcomes include self-rated measures of symptoms of PTSD and complex PTSD, depression, quality of life, cost effectiveness, mediators of change, dropout rates, and adverse events.

DISCUSSION: This study will be the first to compare digital prolonged exposure (HOPE) with an active control condition and not exclude patients with severe or complex PTSD. The strength of the study is that it is conducted in a clinical setting with wide eligibility criteria and the use of gold-standard measures to assess outcomes. Potential challenges in the execution of the trial include participant recruitment, retention, and adherence to treatment and therapist retention.

TRIAL REGISTRATION NUMBER: Clinicaltrials.gov; NCT05934162. Registered 6th July 2023. Open Science Framework https://osf.io/dsg9p/ . Registered 2nd September 2023.