According to the DSM-5 (APA, 2013), hoarding disorder is characterized by the excessive saving, and subsequent accumulation of a large number of possessions, regardless of their value. These possessions can include inanimate objects as well as animals. People with this disorder have an extremely difficult time parting with these possessions despite the harmful consequences of continued accumulation. For instance, hoarding behaviors often result in significant clutter in the home such that living spaces are no longer functional, and/or become unsafe to inhabit.
It is easy to confuse hoarding with collecting, but they are not the same. Collectors take great delight in displaying their items. Their collections are usually exceptionally well-organized, and maintained. Collectors enjoy showing off their prized collections, and speak about their collection with a sense of pride. A good example is Jay Leno's well-known car collection. He takes great pride in his car collection. He often talks about his cars. He frequently shows video clips of his garage where his collection is housed. In contrast, people who hoard can feel quite embarrassed or ashamed. There is no discernible pattern to the accumulation of possessions. Oftentimes valuables such as jewelry, can be mixed in with less valuable items such as old clothing. Unlike collectors, the accumulation of possessions is highly disorganized, and lacks any systematic arrangement, order, upkeep, or care.
Although people with hoarding disorder often think of their possessions in terms of valuable collections, they persistently have difficulty getting rid of their possessions whether or not they have any value. There is a powerful aversion to disposing of these items whether it be by selling them for market value, throwing them away, recycling, or donating them.
People who hoard become distressed when attempting to make decisions about whether to dispose of an item. The reasons for this difficulty are varied. Some people have trouble letting go of possessions because of a sentimental attachment to the objects, or to what those objects represent, such as a bygone era of happier times. Other people have difficulty because they anticipate some future use or benefit of the objects. For instance, they might some day need a particular screw located somewhere in hundreds of jars of miscellaneous hardware. Others may have difficulty because they are afraid of being wasteful, or losing valuable information.
At some point, most people who hoard become aware of the need to get rid of some of their possessions. However, they have a tremendously difficult time making decisions about what to get rid of, and how to get rid of it. As such, they procrastinate and avoid facing the growing accumulation problem. The failure to discard items leads to disorganization and excessive clutter in the location where these items are stored (usually at home). When people hoard, the accumulation mounts to the point where they can no longer use their homes or living space in the intended manner. For instance, they may not be able to sleep in their beds or use their kitchens to cook. This often occurs because the usual storage locations, such as attic, basement, and garage have already become full. Obviously, people without hoarding disorder store things in these same locations. However, once these areas are full, people without hoarding disorder discontinue further accumulation or begin the process of getting rid of things. People with hoarding disorder may also start to occupy other areas such as relatives' homes or vehicles.
Clearly, hoarding interferes with a person's ability to function well. Social impairment includes conflict with family members over the amount and disorganization of their possessions. Similarly, social isolation is likely due to embarrassment and secrecy surrounding the hoarding. Other functional problems include the loss of living space in their home; significant health or safety hazards; legal conflicts with neighbors and community officials, and financial difficulties. Sometimes two or more family members hoard. One of the most tragic cases was the Collyer brothers in New York City. Their shocking story became widely publicized in the late 1940s. Dr. Gail Steketee discusses this case in her podcast interview with David Van Nuys.
Hoarding behavior is three times more likely in older adults (55 and older) when compared to younger adults (34-44 years). However, this is probably because they do not come to the attention of clinicians and researchers until after many years of accumulation. Retrospectively, there is usually evidence that the hoarding behavior began at a younger age. Hoarding behavior can worsen after the loss a family member who helped keep things together and organized.
In additional to hoarding inanimate objects, people may also hoard animals. Animal hoarding is usually accompanied by hoarding of other objects. It is more likely that people who hoard animals live in unsanitary conditions.
The diagnosis of hoarding disorder includes an optional specifier "with excessive acquisition." This specifier indicates a type of hoarding that goes beyond excessive saving and accumulation of things. With excessive acquisition, there is an active, driving need to acquire more and more things. This usually takes the form of buying excessively but it also includes acquiring free items. As with the act of discarding an item, people with excessive acquisition often feel distress when they are prevented from acquiring more items. The majority of people with hoarding do fit these criteria (80-90%).