Hoarding disorder (HD) is a common syndrome that can cause significant problems for individuals, families, and communities. HD is defined as:

1. ongoing problems with discarding or parting with personal possessions, even items with no clear value;
2. strong urges to save items, and distress or indecision about what to discard; and
3. the accumulation of so many items that the space cannot be used for its usual purposes.

HD can cause increased social isolation (due in part to public and self-stigma associated with hoarding challenges), anxiety and depression, and physical safety risks. However, treatment options for HD are limited. One of the best treatments is cognitive behavioral therapy (CBT) with a mental health provider who is trained to treat HD. However, not everyone has access to CBT. Additionally, some people with HD may be unable to go to a mental health provider for treatment. Instead, they may join support groups or contact consumer advocacy groups for help. Therefore, alternative and more accessible forms of treatment are needed. There is some evidence suggesting that support group treatment led by individuals from the community (usually with peers who are in recovery from HD), using a workbook for hoarding, may work as well as CBT to reduce symptoms; however, this treatment has not been well studied, and it has never been compared to CBT.

Objectives: This study will compare the effectiveness of group CBT to peer-facilitated support group treatment based on the workbook Buried in Treasures (BiT).