Hoarding is recognized as a medical disorder, defined as "persistent difficulty discarding or parting with possessions, regardless of the actual value... the accumulation of possessions that congests living areas and substantially compromises their intended use... causing clinically significant distress or impairment in social occupation, or other important areas of functioning (including maintaining a safe environment for self and others)." Elaine Birchall's new book "Conquer the Clutter: Strategies to Identify, Manage, and Overcome Hoarding," offers tools and support to hoarders, potential hoarders, and those who care about them. According to Birchall, there are 21 million people in North America who hoard, and their accumulation of items sometimes leads to social, legal, and medical issues. She joins John now to discuss the disorder and how hoarding can be overcome.