Exposure-based treatment for co-occurring posttraumatic stress disorder and obsessive compulsive disorder in veterans: The feasibility of massed models.

Exposure-based therapies are widely accepted as the gold-standard intervention for both obsessive compulsive disorder (OCD) and posttraumatic stress disorder (PTSD). Despite their co-occurrence, little research has explored exposure-based treatment in individuals who experience both OCD and PTSD. At an academic medical center mental health program, four different treatment approaches combining exposure and response prevention (ERP) and prolonged exposure (PE) therapies were piloted for veterans with co-occurring OCD and PTSD. We present each approach with a brief case study. Two sequential models are discussed: massed PE followed by spaced ERP (Model 1) and ERP "prestart" spaced sessions followed by 1-week massed ERP and then 1-week massed PE (Model 2). Two integrated models are presented: ERP prestart spaced sessions, followed by massed PE with ERP elements integrated (Model 3) and massed ERP with PE integrated (Model 4). The results demonstrate reductions in OCD and PTSD symptom severity for the sequenced treatment, starting with ERP of Model 2, as well as the integrated approaches of Models 3 and 4, which emphasized OCD-related psychoeducation and response prevention prior to beginning imaginal exposure for PTSD. These models showed reliable change (RC) for both OCD (RC = 2.35-4.06) and PTSD (RC: 4.46-7.39). Impacts of these variations in exposure sequencing and spacing are discussed. We provide recommendations for next steps, including systematic research in rigorous and larger-scale studies of exposure-based treatments for co-occurring OCD and PTSD.