Changes in hoarding-related beliefs and associated neural changes during a simulated discarding task after cognitive-behavioral treatment for hoarding disorder.

Hoarding disorder (HD) is maintained by maladaptive beliefs about possessions, and recent research has demonstrated that changes in these beliefs partially mediate improvement in cognitive-behavioral therapy (CBT) for hoarding. It is not yet known whether changes in neural activity, particularly when discarding possessions, are associated with cognitive change during CBT for HD. Adults who completed group CBT for HD (N = 58) participated in a simulated discarding task before and after CBT. Neural activity was measured using functional magnetic resonance imaging (fMRI) as participants made simulated discarding decisions. At baseline, activity in the left middle insula and left anterior cingulate cortex was significantly associated with hoarding-related beliefs. After receiving CBT for HD, decreases in maladaptive hoarding-related beliefs were significantly associated with increased activity compared to baseline in the right anterior ventral insula, along the left middle frontal gyrus and bilateral inferior temporal lobe, and in visuospatial areas. These results demonstrate that maladaptive beliefs in HD are associated with activation of specific neural regions during discarding decisions and that reduction in beliefs over a course of CBT for HD is associated with specific changes in neural activity.