(PS11-B42) Prospective Associations Between OCD Symptoms, Trauma Types, and PTSD Symptom Severity: Findings from a Multi-year Longitudinal Study

Background: Existing literature on the comorbidity between obsessive-compulsive disorder (OCD) and posttraumatic stress disorder (PTSD) has identified a prospective association between the two conditions, such that trauma exposure confers risk for the development of OCD over time. However, there has been a dearth of research on the role of OCD symptom severity as a risk factor for the development or maintenance of PTSD symptoms following a traumatic event. The present study aimed to address this gap in the literature by examining prospective associations between OCD and PTSD symptom severity over a 3-5 year period. Trauma type (sexual violence, physical violence, and non-interpersonal trauma) was also examined as a potential moderator of this relationship.

Method: A sample of N = 303 individuals were recruited for a larger randomized controlled trial (RCT) examining the effects of several brief, computerized treatments for anxiety and mood symptoms. Of this group, 204 participants endorsed experiencing at least one lifetime traumatic event. Participants completed self-report measures of trauma exposure, PTSD symptoms, and OCD symptoms over the course of several years, with the last appointment occurring between 3 to 5 years following the initial study visit. A final sample of n = 92 participants completed symptom measures at both the baseline and long-term follow-up visits.

Results: Hierarchical linear regressions revealed that baseline OCD symptom severity was a statistically significant predictor of PTSD symptoms 3-5 years later (t = 2.08, β = 0.21, p = 0.041), after controlling for baseline PTSD symptoms, treatment condition, and demographic covariates (age and sex). Additionally, the interaction of trauma type experienced and baseline OCD symptoms was also a significant predictor of PTSD symptom severity at long-term follow-up (t = 2.52, β = 0.21, p = 0.014). Results revealed that the longitudinal relationship between baseline OCD symptoms and follow-up PTSD symptoms was statistically significant for individuals who experienced sexual violence (t = 3.16, β = 0.68, p = 0.006), but not physical violence (t = -.96, β = -0.22, p = 0.353) or non-interpersonal trauma types (t = 1.83, β = 0.27, p = 0.074).

Conclusion: The results of the present study indicate that that OCD symptoms may confer risk for the development of PTSD symptoms over time, particularly for individuals who have experienced sexual violence. Thus, intervening upon OCD symptoms following a traumatic event may prevent or ameliorate PTSD symptomatology. Further research is needed to identify potential mediators of this relationship, particularly in large, diverse samples of trauma-exposed populations.