Cognitive functioning in compulsive hoarding.

The aim of this study is to determine whether neurocognitive performance distinguishes individuals with compulsive hoarding (CH) from those with obsessive-compulsive disorder (OCD). Compared to control subjects, OCD patients and CHs scored significantly worse on the Serial Reaction Time Task suggesting disturbed implicit memory in both patient groups. On the Iowa Gambling Task, an overall learning progression difference over time was found between the CHs, OCD group, and control subjects, suggesting differences in decision-making between the groups. The groups did not differ in performance on the Stop Signal Reaction Time Task (motor inhibition). This study found evidence for impaired implicit memory in CHs, but also in OCD patients, albeit less severe. There was evidence that OCD patients learned more slowly on a decision-making task than CHs and control subjects. This latter finding provides some evidence to suggest that CH and OCD have, at least on this one measure, differing cognitive substrates.