Link between brain activation, symptom reduction in OCD specific to CBT

Associations between brain activation and treatment response in adolescents and adults with obsessive-compulsive disorder (OCD) are treatment specific, particularly to cognitive behavioural therapy (CBT) compared with control psychotherapy, a recent study has shown. These associations are stable from adolescence to mature adulthood.

To examine whether brain activity is associated with treatment response to CBT and whether any associations are treatment specific relative to an active control psychotherapy, the investigators randomized 87 patients with OCD (age range, 12–45 years; 57 females; 39 medicated) to receive 12 weeks of CBT or stress management therapy (SMT).

Functional magnetic resonance imaging scans prior to treatment were performed in patients performing an incentive flanker task, which examines brain activation to both cognitive control and reward processing.

Voxelwise linear mixed-effects models were used to determine whether baseline brain activation was differentially associated with change in scores on the Yale-Brown Obsessive Compulsive Scale (standard or Children’s version) over the course of CBT or SMT.

A better treatment response among patients receiving CBT significantly correlated with greater pretreatment activation within the right temporal lobe and rostral anterior cingulate cortex during cognitive control and within the ventromedial prefrontal, orbitofrontal, lateral prefrontal, and amygdala regions during reward processing.

On the other hand, reduced pretreatment activation within a largely overlapping set of regions showed a significant correlation with a better treatment response to SMT.

“Such treatment-specific associations are important for the development of biomarkers to personalize treatment in OCD,” the investigators said.