Is hoarding a kind of obsessive-compulsive disorder?
Right now, compulsive hoarding is considered by many researchers to be a type of obsessive-compulsive disorder. However, for some people, compulsive hoarding may also be related to:  

• Impulse control disorders (such as impulsive buying or stealing)
• Depression
• Social anxiety
• Bipolar disorder
• Certain personality traits

How common is compulsive hoarding? What are its features?

• We don't know exactly. Some researchers have guessed that about half of 1 percent of the population suffers from compulsive hoarding, but the actual number may be much higher.
• People usually start hoarding during childhood or early adolescence, although the problem usually does not become severe until the person is an adult.
• Compulsive hoarding may run in families.
• Many people with compulsive hoarding do not recognize how bad the problem really is; often, it is a family member who is most bothered by the clutter.