A Longitudinal Examination of Obsessive-Compulsive Symptom Severity as a Predictor of Posttraumatic Stress Disorder Development

Abstract

It is well established in literature that Obsessive Compulsive Disorder (OCD) and Posttraumatic Stress Disorder (PTSD) have high rates of comorbidity. Many studies consider trauma exposure as an etiological factor in the development of Obsessive Compulsive (OC) symptoms, however no research to date has considered the contributions of OC symptoms in the development and maintenance of posttraumatic stress symptoms (PTSS) following a traumatic event. Previous literature reports that trauma type and distress tolerance both influence presence and severity of PTSS and OC symptoms. The present study utilizes archival data from 97 trauma-exposed participants selected from a larger randomized controlled trial of four web-based interventions for anxiety and mood symptoms (N = 303). A hierarchical linear regression indicated that baseline OC symptoms predicted long-term follow-up PTSS over and above the variance explained by baseline PTSS, treatment condition, and trauma load. Further, a significant trauma type by OC symptom severity interaction indicated that baseline OC symptom severity had a greater effect on the development or maintenance of PTSS for individuals who experienced interpersonal trauma, as compared to those who experienced non-interpersonal trauma. Additionally, a mediation model demonstrated that month 3 distress tolerance fully mediated the relationship between baseline OC symptoms and long-term follow-up PTSS. The present study was limited by possible treatment effects, outdated methodologies utilized in the original study, and attrition. Despite its limitations the current study provides novel findings and advances our understanding of the relationship between OCD and PTSD symptoms.