This study proposes to compare two forms of treatment for Hoarding Disorder (HD), a common and impairing neuropsychiatric syndrome that has a profound impact on the lives and functioning of individuals, families, and society. Specifically, we will compare a novel community-based group treatment led by individuals from the community who are not mental health professionals to the current standard of care treatment for Hoarding Disorder, cognitive behavioral therapy, conducted by psychologists in a group setting. We hypothesized that both treatment types will be similarly effective in reducing hoarding severity.