Exploring the effects of cognitive behavioral therapy on cognitive control circuit and behavioral task performance in hoarding disorder.

Hoarding disorder (HD) is characterized by difficulty discarding or parting with possessions and clutter, which causes distress or impairment in important areas of functioning. Cognitive behavioral therapy (CBT) for HD has shown promise; however, little is known about the brain mechanisms underlying symptom reduction. We previously reported the robust clinical effects of the Buried in Treasures workshop (BIT)-a skills-based group which incorporates CBT principles-augmented with uncluttering home visits (BIT+), in a waitlist-controlled trial involving adults with HD. This study examined neural activity within a network of regions associated with cognitive control in a subset of HD participants (n = 19) before and after 18 weeks of BIT+ sessions using task-based fMRI during a response inhibition task. We used a comparison group of healthy controls (HC; n = 49). Our behavioral results show that participants in the HD group made more errors of omission while performing the task but did not differ from HCs in their errors of commission. The neuroimaging findings indicated a correlation between improvements in hoarding symptoms and blood-oxygen-level-dependent (BOLD) signal during errors of commission in the right insula and anterior cingulate cortex of post-treatment HD participants, suggesting that changes in this region may be associated with the effectiveness of BIT+ treatment. This is the first study exploring neural activity changes associated with symptom-neutral inhibitory control before and after BIT+ treatment in a HD population.