The primary aim of this pilot randomized controlled trial is to examine whether cognitive remediation, compared to a placebo, improves attention and related cognitive functions in patients with compulsive hoarding. Previous research has demonstrated that hoarders have diminished neuropsychological abilities, particularly in the areas of attention, memory, and executive function; and that cognitive remediation improves those functions in populations that are similarly impaired, such as in individuals with schizophrenia. The investigators will thus randomize 20 patients with compulsive hoarding to receive either cognitive remediation or a placebo condition. Before and after treatment, the investigators aim to assess the effects of cognitive remediation on neuropsychological functioning and hoarding severity. The primary specific aim is to examine whether cognitive remediation improves cognitive function in compulsive hoarders. The investigators hypothesize that compulsive hoarding patients who are treated with cognitive remediation will demonstrate improved cognitive skills at post-treatment compared to patients receiving placebo. This will be especially true of attention; memory and executive function skills may also be improved. A secondary, exploratory aim is to examine whether cognitive remediation improves hoarding severity, compared to placebo. The ultimate goal of this research is to determine the feasibility and appropriateness of pursuing larger-scale studies of the promising new approach of combining cognitive remediation with other treatments for compulsive hoarding—particularly cognitive-behavioral therapy (CBT).