Just as autism was little understood just over decade ago and is now known as a spectrum of disorders Compulsive hoarding is similar and belongs to the Obsessive compulsive Disorder group better known as OCD. Other types of obssesive behaviours are excessive cleaning and handwashing

Compulsive hoarding may be difficult to diagnose, firstly because the person who has it does not acknowledge they have the problems. Secondly the sense of shame attached ot it and the shame for family members. In my personal experience hoarders can be irrational and extrememly defensive and have other behaviour problems such as anger management.

According to Oprah's website there are 2 million people with compulsive hoarding as a problem in the US (unsure where these statistics come from). In the UK i am not aware of any statisitcs.