You've seen them on TV, and you might even know somebody who obsessively hangs onto everything they've ever owned, even if it means they must reside in cluttered, un-navigable houses.
But new research indicates that the brains of hoarders may actually differ from the brains of those without the disorder, casting new light on a poorly understood and often devastating mental illness.
The new study, titled "Neural Mechanisms of Decision Making in Hoarding Disorder," was published online in the Archives of General Psychiatry, and focused on the brain activity of subjects forced to make decisions about objects that did - and did not - belong to them.
The subjects included 43 diagnosed hoarders, 31 people with obsessive-compulsive disorder, and 33 regular "controls," reports Scientific American.
The study, led by David Tolin of the Yale University School of Medicine, found that hoarders found it difficult to discard items that belonged to them - and felt more "anxiety, indecisiveness and sadness" when forced to make these decisions than either subjects with OCD, or "normal" subjects, reported Scientific American.
According to Scientific American, hoarders brains, when examined using an fMRI brain scan, indicated differences in the anterior cingulate cortex - "associated with detecting mistakes during uncertain conditions."
Their brains also differed from the norm when it came to activity in the the mid- to anterior insula, which is "linked to risk assessment, importance of stimuli and emotional decisions."
Interestingly, the study found that hoarding behavior may result because sufferers are deathly afraid of making decisions about possessions - and may stem less from a desire to hold onto everything the hoarder has ever owned, reported Scientific American.
Currently, hoarding is defined as an off-shoot of obsessive-compulsive disorder - but some in the psychiatric community feel that the syndrome deserves its own class in the authoritative Diagnostic and Statistical Manual of Mental Disorders (DSM-5), reports Scientific American.
These new brain findings may help achieve that goal.