The overlap between OCD and PTSD: Examining self-reported symptom differentiation.

The role of stressful precipitating events has long been recognized in the genesis of obsessive-compulsive disorder (OCD). Posttraumatic stress disorder (PTSD) also necessitates the experience of a traumatic event (PTSD criterion A). Research has demonstrated a high degree of comorbidity between these two conditions. However, few studies have examined symptom overlap as a potential cause for this co-occurrence. Thus, the purpose of the present study was to examine symptom endorsement and overlap between OCD and PTSD using a sample of trauma exposed veterans. Veterans were administered self-report assessments, including the Dimensional Obsessive-Compulsive Scale (DOCS) and the PTSD Checklist for DSM-5 (PCL-5), as part of a routine clinical care at a Veteran's Administration hospital. Based on self-report assessment of clinical cut scores, 81% of participants met for probable PTSD and 74% for probable OCD. In addition, a series of chi square analyses revealed frequent overlap of endorsement across items with similar content. There is significant overlap between PTSD and OCD symptoms, and patients may find it difficult to differentiate between them on self-report measures. As such, caution should be used when using self-report solely to assess PTSD and OCD, particularly in traumatized samples.