OBJECTIVE: There is a need to evaluate stepped care approaches for individuals with posttraumatic stress disorder (PTSD). This pilot study tested the efficacy of combining a low-intensity program (This Way Up [TWU]) with the option to step up to an established higher intensity therapy (Cognitive Processing Therapy [CPT]). METHOD: This study was an open trial with participants with predominantly interpersonal trauma ( RESULTS: Among the intent-to-treat sample, 24 participants only required TWU (21 completers), with 14 participants stepped up to CPT (TWU + CPT
nine completers). Significant improvements in PTSD, depression, and quality of life were observed for TWU and TWU + CPT participants, with gains maintained at follow-up. Effect sizes for PTSD outcomes (clinician- and participant-rated) ranged from medium to large, with larger reductions generally in the TWU group (e.g., PTSD gs: 1.96-3.54, vs. gs: 0.48-1.14 for TWU + CPT). Of the participants available at 3-month follow-up, 73% ( CONCLUSIONS: This stepped care approach appeared credible and feasible and demonstrated meaningful impact on mental health for participants who had predominately experienced interpersonal trauma. (PsycInfo Database Record (c) 2025 APA, all rights reserved).