Harm Avoidance and Incompleteness: Understanding the Core Motivational Dimensions of Obsessive-Compulsive Disorder

Abstract

Obsessive-compulsive disorder (OCD) affects millions worldwide, yet our understanding of its underlying mechanisms remains to be better understood. Traditionally, OCD has been examined through its overt symptom presentations, but there is growing evidence for a motivational perspective. The Core Dimensions Model posits harm avoidance (HA) and incompleteness (INC) as core motivations driving OCD. This dissertation aims to deepen our understanding of HA and INC in OCD across three studies, examining their phenomenology, measurement, and response to treatment. Chapter 2 utilized experience sampling methodology to capture the daily manifestations of HA and INC in a clinical OCD sample, identifying four distinct motivation profiles. Findings demonstrated that both HA and INC are relatively stable over time, though individual fluctuations suggest state-level variability. HA and INC showed unique relationships with the cognitive and behavioural responses to OCD experiences, providing insight into potential treatment targets. Chapter 3 concurrently evaluated the psychometric properties of two common measures, the Obsessive-Compulsive Core Dimensions Questionnaire (OC-CDQ) and the Not Just Right Experiences Questionnaire-Revised (NJREQR), to help inform their use. Results supported their reliability and validity, with the OC-CDQ proving effective for assessing trait-like motivations and the NJRE-QR capturing state-like not-just-right experiences. Both tools demonstrated sensitivity to change following group CBT, underscoring their utility for tracking core motivations across treatment. Chapter 4 investigated changes in HA and INC across group CBT for OCD, assessing their impact on treatment outcomes. While both motivations significantly decreased following treatment, pre-treatment HA and INC levels did not predict symptom severity post-treatment. However, reductions in HA and early decreases in INC were linked to better treatment outcomes, suggesting these motivations’ relevance for predicting therapeutic success. Together, these studies highlight the importance of understanding HA and INC in OCD, offering valuable insights for personalized assessment and intervention approaches that address the disorder’s motivational underpinnings.