Spring PGD versus waiting list control in the treatment of prolonged grief disorder (PGD): protocol for a feasibility randomised controlled trial (RCT).

Background: Prolonged Grief Disorder (PGD) is characterised by persistent longing or preoccupation with a deceased loved one, accompanied by intense emotional pain that lasts six-months or more and significantly impairs functioning. While Cognitive Behavioural Therapy (CBT) with a grief focus is effective, access is limited due to high costs and therapist shortages. Guided digital therapy, which delivers psychological support via an app or website with professional guidance, may offer a scalable solution. Building on the success of a guided digital intervention for post-traumatic stress disorder (PTSD), this study evaluates a similar intervention for PGD in a UK-based randomised controlled trial (RCT).Objective: This study aims to assess the acceptability and feasibility of Spring PGD, a co-produced guided digital therapy for PGD, in preparation for a future definitive RCT.Methods: This exploratory, randomised, parallel-group controlled trial will allocate 42 participants in a 1:1 ratio to either immediate access to Spring PGD or a waiting list control group. After 11 weeks, control participants will cross over to receive Spring PGD. The primary outcome measure is the Prolonged Grief 13 Revised (PG-13-R). A nested process evaluation will explore fidelity, adherence, and programme theory through interviews with purposively sampled participants and therapists.Results: Findings will provide preliminary data on the acceptability, engagement, and feasibility of Spring PGD, informing the design of a future definitive RCT.Conclusions: If Spring PGD shows promise, it could offer an accessible, scalable treatment for PGD, particularly in areas with limited access to specialised mental health services. The results will contribute to understanding the potential of guided digital therapy in addressing gaps in PGD treatment.