1. ¹Department of Psychological Medicine, Institute of Psychiatry, King's College London, London, UK
2. ²Department of Psychiatry, Yonsei University College of Medicine, Seoul, South Korea
3. ³Institute of Behavioural Science in Medicine, Yonsei University College of Medicine, Seoul, South Korea
4. ⁴Department of Psychology, Institute of Psychiatry, King's College London, London, UK
5. ⁵Department of Neuroimaging, Institute of Psychiatry, King's College London, London, UK
6. ⁶Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA

Correspondence: Dr D Mataix-Cols, Section of Neuroscience and Emotion, Institute of Psychiatry, King's College London, De Crespigny Park, PO Box 69, London SE5 8AF, UK. E-mail: d.mataix@iop.kcl.ac.uk

Received 4 December 2006; Revised 17 October 2007; Accepted 23 October 2007; Published online 8 January 2008.

Abstract

Preliminary neuroimaging studies suggest that patients with the 'compulsive hoarding syndrome' may be a neurobiologically distinct variant of obsessive-compulsive disorder (OCD) but further research is needed. A total of 29 OCD patients (13 with and 16 without prominent hoarding symptoms) and 21 healthy controls of both sexes participated in two functional magnetic resonance imaging experiments consisting of the provocation of hoarding-related and symptom-unrelated (aversive control) anxiety. In response to the hoarding-related (but not symptom-unrelated) anxiety provocation, OCD patients with prominent hoarding symptoms showed greater activation in bilateral anterior ventromedial prefrontal cortex (VMPFC) than patients without hoarding symptoms and healthy controls. In the entire patient group (n=29), provoked anxiety was positively correlated with activation in a frontolimbic network that included the anterior VMPFC, medial temporal structures, thalamus and sensorimotor cortex. Negative correlations were observed in the left dorsal anterior cingulate gyrus, bilateral temporal cortex, bilateral dorsolateral/medial prefrontal regions, basal ganglia and parieto-occipital regions. These results were independent from the effects of age, sex, level of education, state anxiety, depression, comorbidity and use of medication. The findings are consistent with the animal and lesion literature and several landmark clinical features of compulsive hoarding, particularly decision-making difficulties. Whether the results are generalizable to hoarders who do not meet criteria for OCD remains to be investigated.