Internet Cognitive Therapy for Prolonged Grief Disorder (iCT-PG): A developmental case series

Background:Prolonged Grief Disorder (PGD) affects a significant minority of bereaved individuals and is associated with persistent distress, comorbidity, and functional impairment. Access to evidence-based treatment remains limited. This study introduces and evaluates Internet Cognitive Therapy for Prolonged Grief (iCT-PG), a therapist-assisted digital intervention adapted from iCT-PTSD. Objective: To assess preliminary feasibility, acceptability, and clinical outcomes of iCT-PG, and its impact on key cognitive maintenance mechanisms of PGD. Methods: Eight adults meeting diagnostic criteria for PGD completed the 12-session iCT-PG programme over 14 weeks. The intervention targeted loss-related memory characteristics, negative grief appraisals, a sense of social disconnection, and unhelpful coping strategies, and used a personalised digital modular approach and therapist support through weekly calls and messages. Outcomes were assessed at pre-treatment, post-treatment, and 3-month follow-up using validated measures. Results: All participants completed treatment. Large reductions in PGD symptoms and comorbid symptoms of PTSD, depression, anxiety, and functional impairment were observed. At post-treatment, 87.5% (7/8) demonstrated both reliable improvement in PGD symptoms on the Reliable Change Index, and recovery below clinical cut-offs. There was no reliable deterioration on any measure. Process measures showed large effect sizes, with the strongest improvements in loss-related memory characteristics. Therapeutic gains were maintained at 3-month follow-up. Average therapist time was approximately 10 hours per participant. Conclusions: iCT-PG was feasible, well-accepted, and associated with substantial clinical improvement. The intervention successfully targeted mechanisms known to maintain PGD, supporting its theoretical foundation. Though uncontrolled and small in sample size, findings support further evaluation in larger trials to determine efficacy and scalability.