(PS7-B48) The Phenotypic Profile of the Contamination-cleaning Symptom Dimension in Obsessive-compulsive Disorder: Role of Executive Function and Personality Traits

Background. Obsessive-compulsive disorder (OCD) comprises disgust-based contamination-cleaning symptoms (insula), fear-related obsessions (hippocampus, amygdala) and ritualistic behaviors (dorsal striatum). Insula activation is associated with the expression of disgust, OCD contamination fears, as well as aspects of morality and sensitivity, suggesting that contamination-cleaning symptoms have a unique phenotypic expression in OCD. The study aims to identify the unique characteristics of the contamination-cleaning symptoms of OCD relevant to executive function and personality.

Methods. Data were accrued in the Obsessive-Compulsive Collaborative Genetics Study (OCGAS). Structured interviews identified participants with OCD in families. The Behavior Rating Inventory of Executive Function (BRIEF) assessed executive function, and the Revised NEO Personality Inventory (NEO-PI-R) measured personality. A tetrachoric matrix factor analysis derived OCD symptom dimensions, and continuous factor scores were generated. Regression analyses examined whether the contamination-cleaning dimension predicted the global executive composite score (GEC) of BRIEF [behavioral regulation index (BRI) + metacognitive index (MI)] and the five personality traits (neuroticism, extroversion, agreeableness, openness, and conscientiousness) in NEO-PI-R. The generalized estimating equations (GEE) routine accounted for correlated data (software used: STATA).

Results. 769 adults with OCD from 531 families (33% male, 94% Caucasian, 38.6 ± 13.9 years) completed the BRIEF (n=412) and the NEO-PI-R (n=758). Tetrachoric matrix factor analysis identifies four factors: 1) hoarding (λ=2.08); 2) contamination-cleaning (λ=1.94); 3) fear-based obsessions (λ=1.68); and 4) rituals (λ=0.97). For executive function, the contamination-cleaning factor is significantly predictive of better MI (b=-3.1, p< 0.05) but not better GEC or BRI. Of the MI components, improved working memory (b=-3.4, p< 0.05), planning/organizing (b=-3.4, p< 0.05), and organization of materials (b=-4.5, p< 0.001) are found. For personality traits, higher neuroticism is associated with increased factor scores for hoarding, fear-based, and ritualistic dimensions, but not for contamination-cleaning. Contamination-cleaning is also predictive of higher conscientiousness (b=2.7, p< 0.05) [orderliness (b=6.0, p< 0.001) facet] and higher agreeableness (b=2.3, p< 0.05) [straightforwardness (b=4.3, p< 0.01), altruism (b=3.7, p< 0.05), modesty (b=5.2, p< 0.01) facets].

Conclusion: The contamination-cleaning dimension of OCD is not associated with neuroticism in contrast to other OCD symptom dimensions, but it is associated with increasing cognitive executive function (working memory, orderliness, planning), and personality traits reflective of pulchritude (conscientiousness and agreeableness). Psychological aspects such as agreeableness, orderliness, and perfectionism should be considered during the execution of CBT for those patients with prominent contamination/cleaning symptoms. Aspects of morality and sensitivity, which underlie the complex expression of the OCD contamination-cleaning dimension, also need to be considered.