Functional Neuroimaging Test of an Emerging Neurobiological Model of Hoarding Disorder.

BACKGROUND

Over the past decade, functional neuroimaging studies have found abnormal brain function in several cortical systems when patients with compulsive hoarding behaviors make decisions about personal possessions. The purpose of this study was to use functional magnetic resonance imaging to test a neurobiological model of hoarding disorder (HD) that has begun to emerge from these small studies by confirming HD-related brain dysfunction in previously implicated brain regions in the largest sample of HD patients examined to date.

METHODS

We compared 79 adults diagnosed with DSM-5 HD with 44 non-HD control participants using a functional magnetic resonance imaging task of decision making to acquire or discard material possessions and on a control task involving semantic processing.

RESULTS

HD brain activation profiles prominently featured insular and anterior cingulate cortex overengagement during possession-related choices that were not seen in non-HD brain activation profiles and also correlated with hoarders' clutter and difficulty discarding. Although HD patients overengaged the insula when deciding to discard, relative to when performing the non-decision making task contrast, the HD insula also was generally blunted.

CONCLUSIONS

This study links the defining behavioral symptoms of HD to localized brain dysfunction within cingulo-opercular brain systems and firmly establishes the context-dependent importance of this network dysfunction in HD. The relevance of dysfunction in these brain regions is highlighted by a failure to replicate HD-related abnormalities in other brain regions implicated in prior HD functional magnetic resonance imaging studies. This study also raises the novel possibility that HD may involve abnormality in the inferior frontal cortex engaged for executive control over semantic processing.