Course and Prognosis
Hoarding Disorder is associated with a particularly chronic course and poor prognosis for standard treatments using medication and cognitive behavioral therapy. This may be due to many individuals displaying a striking lack of awareness of the severity of their behavior, often resisting intervention attempts and defensively rationalizing their acquisition and saving.
A growing body of evidence points to the substantial social burden imposed by hoarding. A large sample of individuals with self-identified compulsive hoarding reported a mean 7.0 psychiatric work impairment days per month, equivalent to that reported by participants with bipolar and psychotic disorders. Eight percent reported that they had been evicted or threatened with eviction due to hoarding.
Several other conditions can lead to clutter in the living space and difficulty discarding possessions.
For example, hoarding behaviors occur in individuals with Prader-Willi syndrome, a rare genetic disorder associated with short stature, hyperphagia, insatiability, and food-seeking behavior. Many individuals with Prader-Willi syndrome display hoarding behavior, mostly associated with food, but also non-food items as well.
Hoarding associated with dementia appears to stem from significant cognitive deterioration rather than from excessive attachment to objects. The person forgets what they have and perhaps repeatedly buys the same things to excess.
Hoarding has also been described in individuals with schizophrenia, but the behavior does not appear motivated by a true attachment to objects. For example, paranoia may make throwing things out difficult due to worries that someone is monitoring their garbage.
Available data suggest that a range of insight can characterize Hoarding Disorder. When severe, the hoarding may appear delusional, especially if the items are unsanitary. In the context of hoarding, however, this lack of insight may better be characterized as over-valued ideation which involves beliefs about the value or usefulness of possessions. Many individuals with hoarding recognize the problem with their behavior, but their unreasonable ideas about the value of their possessions make it impossible for them to discard. This may appear to an observer as psychotic, but in reality these beliefs about the value and usefulness of possessions may represent part of the disorder.
Obsessive compulsive disorder is the disorder most closely associated with hoarding, and a significant number of individuals with OCD have hoarding symptoms (25-30%). For example, someone with contamination obsessions may find it difficult to discard items because the items cannot be touched with excessive anxiety.
Individuals with Major Depressive Disorder, GAD, and/or Social Phobia may find it too difficult to clean their homes and discard items due to lack of energy and hopelessness and inability to go outside of the house. They may therefore end up living in squalor similar to someone with hoarding but these individuals do not keep items due to a desire to save or distress from discarding items.