Efficacy of an integrative CBT for prolonged grief disorder: A long-term follow-up

•Patients with prolonged grief disorder (PGD) had participated in a randomized controlled trial.•They were followed up 1.5 years after integrative cognitive behavioral therapy for PGD.•Post and follow-up ES for prolonged grief symptoms were large.•The pre to post-improvement in overall mental health was maintained.•This is the largest PGD treatment sample followed up for this long so far.

BackgroundWhile some intervention trials have demonstrated efficacy in treating prolonged grief disorder (PGD), data on long-term treatment effects are scarce.MethodsFifty-one outpatients with clinically relevant prolonged grief symptoms, who had participated in a randomized controlled trial (RCT), were followed up, on average, 1.5 years after integrative cognitive behavioral therapy for PGD (PG-CBT). Initial assessment procedures were repeated, with PGD symptom severity as the main outcome and general mental health symptoms as secondary outcomes. As results in the immediate and delayed treatment groups (former wait list) were similar, the follow-up data were pooled.ResultsOverall, 80% of the original ITT sample could be reached, that is 89% of the 37 treated participants, as well as 8 out of 14 participants who had dropped out of the RCT. The considerable short-term treatment success of PG-CBT was stable; pre to follow-up Cohen׳s d was large, with 1.24 in the ITT analysis and 2.22 for completers. The pre to post-improvement in overall mental health was maintained.LimitationsSince the RCT wait list group had been treated after their waiting period as well, no controlled long-term outcomes are available.ConclusionsPG-CBT proved to be effective in the longer run. In comparison to other RCTs on prolonged grief this is the largest sample followed up for this long.