The psychology behind hoarding is complex. It is characterized by excessively acquiring, saving, and often storing random items in a haphazard manner that disrupts the normal functioning of household spaces. Research suggests that hoarders believe that such items are useful, will be needed in the future, are a good bargain, or are unique and irreplaceable. They also may attach sentimental value to otherwise useless items.
Hoarding is a form of obsessive compulsive disorder (OCD). Experts estimate that 25% of people with OCD are also compulsive holders. Further, most hoarders experience anxiety disorders ranging from mild anxiety to depression. Hoarding also leads to social isolation, which increases their susceptibility to mental disorders. Some people turn to hoarding as a way of dealing with trauma while others use the habit to manage worry, anxiety, and fear.