Abstract
Many individuals with posttraumatic stress disorder (PTSD) continue to have substantial residual symptoms after completing psychological treatment. Well‐being therapy (WBT) has been developed to treat the residual phase of mental disorders, prevent relapse, and promote a full recovery. The present study aimed to compare treatment as usual (TAU) with the long‐term effects of WBT as a rehabilitation therapy in adults who successfully completed psychological treatment for PTSD. Participants who did not meet PTSD diagnostic criteria after completing treatment were randomized to WBT (n = 29) or TAU (n = 35) groups. Assessments of well‐being, residual PTSD symptoms, and posttraumatic growth were conducted at baseline (T0) and again after 3 months (T1), 6 months (T2), and 1 year (T3). The results of the multilevel analysis revealed that WBT was not more effective than TAU in increasing levels of well‐being, γ = 0.02 (SE = 0.11) or posttraumatic growth, γ = 0.10 (SE = 0.13) nor in decreasing PTSD symptoms, γ = −0.04 (SE = 0.05). However, for participants with low levels of well‐being at baseline (Mental Health Continuum‐Short Form score < 2.6), WBT was more effective than TAU in increasing ratings of well‐being, γ = −0.41 (SE = 0.19) and posttraumatic growth, γ = −0.55 (SE = 0.24); this effect was most evident at T3 for posttraumatic growth, d = 1.23. Future research should assess clinically relevant individual characteristics that to optimize the effectiveness and utility of WBT.