Changes in harm avoidance and incompleteness across group CBT for OCD and their relationship with symptom change

Background: Obsessive-compulsive disorder (OCD) symptoms are hypothesized to be driven by two core motivations: harm avoidance and incompleteness. While cognitive-behavioural therapy (CBT) is an effective treatment for OCD, many posit that OCD presentations characterized by high incompleteness may be harder to treat. The relationship between the core motivations and treatment outcomes remains to be further explored. Aims: To investigate if harm avoidance and incompleteness decrease across group CBT and to examine the relationship between treatment outcomes and both baseline and changes in harm avoidance and incompleteness throughout treatment. Method: A naturalistic sample of 65 adult out-patients with OCD completed self-report questionnaires measuring OCD symptom severity and the core motivations before, during, and after 12 weeks of group CBT for OCD. Results: Harm avoidance and incompleteness scores significantly decreased from pre- to post-treatment. Pre-treatment harm avoidance and incompleteness levels did not predict post-treatment symptom severity, but changes in the core motivations throughout treatment were significant predictors of treatment outcome. Specifically, reductions in harm avoidance across treatment and reductions in incompleteness early in treatment, were associated with better treatment outcomes. Conclusions: Participants who completed group CBT for OCD experienced modest reductions in the core motivations thought to maintain OCD symptoms and these changes predicted better outcomes. However, pre-treatment levels of harm avoidance and incompleteness do not appear to moderate treatment outcome.