Complex brain networks mediation of neuroticism and extraversion on obsessive-compulsive disorder

Personality traits significantly influence obsessive-compulsive disorder (OCD), yet their underlying neural mechanisms remain poorly defined. This study aimed to identify complex brain networks that mediate the association between personality traits and OCD, offering novel insights for personalized interventions.

We recruited 211 OCD patients who underwent clinical evaluations and rs-EEG recordings. Personality traits were measured using the Revised NEO-Five Factor Inventory, and OCD severity was assessed with the Yale-Brown Obsessive-Compulsive Scale by clinicians. Complex brain networks were analyzed using minimum spanning tree. Machine learning and mediation analyses validated relationships between personality traits, complex brain networks, and OCD.

Neuroticism positively correlated, and extraversion negatively correlated with OCD. Delta and theta bands complex brain networks (diameter, mean eccentricity, leaf fraction, kappa) significantly associated with OCD. Theta diameter partially mediated associations between both neuroticism and extraversion with OCD, whereas theta mean eccentricity partially mediated the relationship specifically between extraversion and OCD.

Our findings highlight distinct theta diameter as neural mediators linking neuroticism and extraversion to OCD. These results suggest theta band focused neuromodulation as a potential therapeutic strategy tailored to individual personality profiles.