Date of Submission


Degree Type


Degree Name

Doctor of Psychology (PsyD)

Department Chair

Stephanie Felgoise, PhD, ABPP

First Advisor

Elizabeth A. Gosch, PhD, ABPP

Second Advisor

Susan Panichelli Mindel, PhD

Third Advisor

Jeremy Tyler, PsyD


Despite the high prevalence of trauma in treatment-seeking individuals with obsessive-compulsive disorder (OCD), the role of trauma in OCD treatment is under-studied. This study examined the relationship between trauma and treatment outcomes using a gold standard intervention for OCD—exposure and response prevention (Ex/RP) therapy. This study also investigated whether inherent traits (intolerance of uncertainty, anxiety sensitivity, emotion regulation, and perfectionism) act as mechanisms of change that mediate the relationship between trauma and Ex/RP treatment outcomes. Using data collected as part of a larger research study, analyses were performed for 76 adult patients with a primary diagnosis of OCD who completed Ex/RP therapy in a naturalistic treatment setting, 28 of whom reported experiencing at least one traumatic life event. Although no inherent traits proposed mediated the relationship between trauma and change in OCD symptom severity, results of the study reveal that both the trauma and non-trauma groups experienced significant reductions in OCD symptom severity from pre- to post-Ex/RP. Moreso, individuals with trauma evidenced a slightly greater reduction compared to their non-trauma counterparts. This study is the first of its kind to look at how individuals with OCD and trauma might respond differentially to Ex/RP therapy compared to their non-trauma counterparts, with consideration for these inherent mechanisms of change. Our findings contribute to the body of literature supporting the use of Ex/RP therapy for OCD while offering new insights into the relationship between trauma and treatment outcomes.