Hoarding

Abstract

Hoarding is a type of behavior: the persistent acquisition of possessions combined with an inability to discard them, so that living spaces fill with clutter until they can no longer be used for their intended purpose. Cognitive psychology treats hoarding not as untidiness but as the visible output of ordinary cognitive processes gone awry — decision making, categorization, memory, and attention operating under beliefs that give possessions outsized value. The dominant account, the cognitive-behavioral model of Frost and Hartl, locates the problem in information-processing deficits and in emotional attachments that make discarding feel like a loss. This article defines hoarding, separates it from normal saving and from collecting, sets out the cognitive-behavioral model, describes how the behavior is measured, reviews the treatments that help, and explains how it relates to the clinical diagnosis of hoarding disorder.

Keywords: hoarding, decision making, executive function, information processing, clutter

Most people keep more than they strictly need, and almost everyone has discarded something and later wished they had not. Hoarding is the far end of that ordinary tension between keeping and letting go — a point at which the accumulated clutter stops being a matter of taste and starts to defeat the function of the home: counters that cannot be cooked on, beds that cannot be slept in, exits that cannot be reached. What makes hoarding a subject for cognitive psychology rather than for housekeeping is that the clutter is a symptom of how a person processes information about their possessions, not a failure of effort or will.

The cognitive-behavioral model that organizes the field treats each possession as the object of a rapid decision — keep or discard — shaped by beliefs about responsibility, memory, waste, and identity. When those beliefs assign high value to almost everything, and when the act of deciding is itself effortful and aversive, the rational response is to postpone: to keep the object and avoid the decision. Hoarding, on this account, is what the postponement of thousands of such decisions looks like when it accumulates over years.

What Hoarding Is

Hoarding has three defining features, and all three must be present before ordinary accumulation becomes the phenomenon the research literature studies. The first is acquisition: the person acquires possessions — by buying, by collecting free items, and sometimes by taking what others discard — at a rate and in a volume that outstrips any use for them. The second is difficulty discarding: parting with possessions is experienced as distressing, and so is avoided, regardless of the object's actual value. The third is clutter: the combined result is that living spaces become so filled that they can no longer serve their purpose (Frost & Hartl, 1996; Frost & Gross, 1993).

The third feature is what distinguishes hoarding from the first two taken alone. A person can acquire heavily and still live in an ordered home if they discard at the same rate; a person can find discarding painful and still avoid clutter if they rarely acquire. Hoarding is the conjunction — high acquisition, low discarding — compounding over time until the volume overwhelms the space. The first demonstration lets the reader tip exactly this balance, adjusting the weekly rates of acquiring and discarding and watching a room cross from ordered into overwhelmed over the course of a year.

Two neighboring behaviors are routinely confused with hoarding and are worth separating explicitly. Normal saving is selective and instrumental: the saved object has a reasonably foreseeable use, and the saver can discard it without undue distress when that use passes. Collecting is organized, bounded, and a source of pleasure: a collection is curated around a theme, displayed rather than piled, and the collector can usually say why each item belongs and what the collection is for (Nordsletten & Mataix-Cols, 2012). Hoarding has neither the instrumental selectivity of saving nor the organized boundedness of collecting; its accumulation is indiscriminate, its storage chaotic, and its emotional tone is anxiety about loss rather than pleasure in possession.

It also matters that hoarding is, in the first instance, a behavior — a pattern of acquiring and keeping — and only secondarily a diagnosis. The same behavioral pattern, when it reaches clinical severity and causes significant distress or impairment, defines hoarding disorder, a mental condition formally recognized in the DSM-5 in 2013 and distinguished there from obsessive-compulsive disorder, with which it had long been grouped (Mataix-Cols et al., 2010; Pertusa et al., 2010). The impairment is not trivial: severe hoarding carries a substantial economic and social burden, including threats to health and safety and high rates of occupational and social disruption (Tolin et al., 2008). This article is about the behavior and the cognition behind it; the clinical disorder is the behavior at its disabling extreme, and the two should not be equated — most people who keep too much are not disordered, and the diagnostic threshold is deliberately high.

The Cognitive-Behavioral Model

The model that organizes the field was set out by Frost and Hartl in 1996 and refined steadily since. Its central claim is that hoarding is not a disorder of possessions but a disorder of processing — the possessions are merely where the processing failures become visible. Four cognitive domains do the work.

Information-processing deficits. People who hoard show measurable difficulties in several basic cognitive operations that bear directly on managing possessions. Attention is one: difficulty sustaining focus and filtering distraction makes sorting a pile exhausting and easy to abandon. Categorization is another: possessions are experienced as unique and non-substitutable, so each must be considered individually rather than filed under a general rule, which makes the sorting task combinatorially large. Memory concerns are a third: a mistrust of one's own memory makes keeping objects in plain view feel necessary, because storing them away is felt to risk forgetting them entirely. Decision making is the fourth and the most central: deciding whether to keep or discard is slow, effortful, and avoided, and the overlap of hoarding with indecision is one of the model's best-supported predictions (Frost & Hartl, 1996; Steketee & Frost, 2003).

Beliefs about possessions. Layered on top of the processing deficits are beliefs that inflate the value of objects. These cluster into a few recurring themes: sentimental beliefs (the object is part of who I am, or a link to a person or past that discarding would sever); instrumental beliefs (the object will be useful or needed one day, and discarding it would be wasteful or irresponsible); and memory beliefs (I must keep the object visible or I will lose the information it carries). Each belief, taken on its own, is a perfectly ordinary human thought. Hoarding arises when they are held rigidly, applied to almost everything, and left to drive behavior unchecked (Steketee & Frost, 2003; Frost, Steketee, & Tolin, 2012). The different reasons people give for saving and for acquiring are not interchangeable: sentimental, instrumental, and memory motives each independently predict distinct facets of hoarding severity (Dozier & Ayers, 2014).

Emotional attachment and avoidance. The beliefs give objects emotional weight, and so the prospect of discarding provokes genuine distress — grief, anxiety, the fear of a mistake. Here the behavioral half of the model takes over. Because discarding is aversive and keeping removes the aversive feeling, keeping is negatively reinforced: each time the person avoids a discard decision and feels the relief of having kept the object, the avoidance is strengthened. Over thousands of repetitions the pattern becomes automatic, which is why hoarding is so resistant to the simple instruction to discard — the advice targets the behavior while leaving the reinforcement loop that drives it untouched (Frost & Hartl, 1996).

The model's explanatory power is that it ties a visibly extreme outcome to perfectly ordinary mechanisms. Everyone categorizes, everyone forms attachments, everyone avoids unpleasant decisions. Hoarding is what happens when those universal processes combine and amplify, not a separate faculty that only some people possess.

Assessment

Because hoarding is defined by behavior and its physical consequences, it can be measured with some precision, and standardized instruments are central to both research and treatment planning. Three are in wide use.

The Saving Inventory-Revised is a self-report questionnaire that yields separate scores for the three defining components — excessive acquisition, difficulty discarding, and clutter — so that a clinician can see which of the three is driving a given person's problem (Frost et al., 2012). The Hoarding Rating Scale-Interview is a brief five-item clinician interview covering clutter, difficulty discarding, acquisition, distress, and impairment, designed to be administered quickly and to track change over treatment (Tolin, Frost, & Steketee, 2010). The Clutter Image Rating takes a different and ingenious approach: for each of three rooms — kitchen, living room, bedroom — the person selects which of nine photographs, graded from empty to impassable, best matches their own room. Because the rating is anchored to images rather than to a subjective adjective, it sidesteps the tendency of people who hoard to under-report, and it gives different raters a common standard (Frost et al., 2012).

The second of this article's demonstrations reproduces the logic of the Clutter Image Rating, letting the reader move a severity slider and see how the standardized anchors map onto a clinical threshold.

Treatment

Hoarding responds to treatment, though less completely than the anxiety disorders it superficially resembles. The best-supported approach is a cognitive-behavioral therapy specifically adapted for hoarding, which differs from standard anxiety-disorder CBT in targeting the particular processing deficits and beliefs the model identifies. Its components typically include skills training in categorizing and organizing, practice at decision making applied to real possessions, cognitive work on the beliefs that inflate object value, graded practice at discarding and at resisting acquisition, and motivational work to sustain engagement — because insight into the problem is often limited and dropout is high (Steketee & Frost, 2003).

A meta-analysis of this adapted CBT found reliable but moderate benefit: clutter, difficulty discarding, and acquisition all improved, with the largest gains for difficulty discarding and the smallest for acquisition, and with younger age and female sex predicting better response (Tolin et al., 2015). Group-delivered CBT, more economical than individual therapy, produces comparable improvement and is increasingly used where resources are constrained (Bodryzlova et al., 2019). Across trials, though, many participants retain clinically significant symptoms at the end of treatment, which is why hoarding is considered one of the more treatment-refractory problems in the field and why the search for better interventions is active (Davidson et al., 2019).

Pharmacological treatment has a thinner evidence base. Because hoarding was long classified with obsessive-compulsive disorder, the serotonin-reuptake inhibitors used for OCD have been tried, with modest and inconsistent results; no medication is established as a first-line treatment, and the behavioral and cognitive work remains the core of care (Nakao & Kanba, 2019).

Worked Example

Consider how the model predicts whether a single object is kept or discarded, framed as a simple weighing of the pulls toward keeping against the effort of deciding.

Suppose a person is sorting a drawer and encounters an old receipt. The cognitive-behavioral model says the keep decision is driven by the summed strength of the beliefs the object activates. Assign each belief a weight on a 0-to-1 scale reflecting how strongly it is held for this object:

- sentimental value: 0.10 (it is only a receipt) - instrumental value: 0.55 (it might be needed for a return or for taxes) - memory value: 0.40 (discarding it risks forgetting the purchase entirely)

A simple additive model sets the pull toward keeping as the sum of the activated beliefs, capped at 1. Here that is 0.10 + 0.55 + 0.40 = 1.05, which caps at 1.00 — an essentially maximal pull toward keeping, even though an outside observer would call the receipt worthless.

Now set this against the cost of deciding. The model treats the discard decision as carrying an effort-and-distress cost; call it d = 0.30 on the same scale. The person discards only when the pull toward keeping falls below this decision cost — that is, when keeping is so weakly motivated that it is not worth even the small effort of thinking it through. With a keep pull of 1.00 against a decision cost of 0.30, the object is kept: 1.00 > 0.30.

The instructive part is what the model predicts under intervention. Cognitive therapy works on the belief weights: challenging the instrumental belief — that receipts older than the return window are useless — might drop that term from 0.55 to 0.05, and challenging the memory belief — that the bank statement already records the purchase — might drop it from 0.40 to 0.05. The keep pull becomes 0.10 + 0.05 + 0.05 = 0.20, now below the 0.30 decision cost, and the object is discarded. The arithmetic makes the model's core clinical claim concrete: hoarding behavior changes not by forcing the discard but by deflating the beliefs that make keeping feel mandatory.

Figure 1

The keep-or-discard decision as a weighing of summed belief pulls against the cost of deciding.

The third demonstration lets the reader set these belief weights directly and watch the keep-or-discard verdict flip as the pulls cross the decision threshold.

Discussion

The cognitive-behavioral model has been productive precisely because it is mechanistic: it names specific processes — categorization, memory confidence, decision cost, negatively reinforced avoidance — each of which can be measured and each of which suggests a point of intervention. Its weaknesses are the weaknesses of its evidence base. Much of the processing-deficit research is cross-sectional, so it cannot show whether the deficits cause the hoarding or develop alongside it; the attachment-and-belief work relies heavily on self-report, which is exactly where people who hoard are least reliable; and the treatment literature, while it establishes that adapted CBT helps, also establishes that it does not help enough, leaving many people impaired at the end of a full course.

A second open question is the relationship between the behavior this article describes and the disorder that shares its name. The behavior exists on a continuum — from the mildly overstuffed closet to the impassable home — and the diagnosis draws a threshold across that continuum at the point of significant distress or impairment. Where exactly to draw it, and whether the cognitive mechanisms are the same all along the continuum or change in kind at the clinical extreme, is unsettled. The behavior and the condition are related but not identical, and the model is a model of the behavior; how far it scales to explain the full clinical disorder, and its comorbidity with depression, anxiety, and attention problems, remains a research question rather than a settled fact (Frost, Steketee, & Tolin, 2011).

Current Directions

The most active current questions concern prevalence, aging, and mechanism. A systematic review and meta-analysis put the population prevalence of clinically significant hoarding at roughly 2.5%, markedly higher than the figure once assumed and comparable to other common mental conditions — a finding that reframed hoarding from a rarity into a public-health concern (Postlethwaite, Kellett, & Mataix-Cols, 2019). Prevalence also rises steeply with age — a population study found hoarding roughly three times as common in the oldest age band as in the youngest (Cath et al., 2017) — and because clutter in an older adult's home creates fall and fire risks that compound medical frailty, late-life hoarding has become a research focus in its own right, with work on cognitive rehabilitation and exposure approaches adapted for older clients (Davidson et al., 2019; Nakao & Kanba, 2019).

On the mechanistic side, the research front is pushing past self-report toward the laboratory: tasks that measure actual sorting and discarding behavior, studies of the neural response when people who hoard contemplate discarding their own possessions — an early functional-imaging study found abnormal activity in cortical regions governing decision making and emotional regulation during exactly this task (Saxena et al., 2004) — and attempts to tie the information-processing deficits to specific executive functions rather than to a vague global impairment (Davidson et al., 2019). The practical motivation is clear — adapted CBT helps only moderately, so a sharper account of exactly which process fails for a given person is the most promising route to a treatment that helps more.

Common Misconceptions

Hoarding is just extreme laziness or messiness.

The clutter is a symptom, not the problem. It results from genuine difficulties in categorizing, deciding, and tolerating the distress of discarding; effort is not the missing ingredient, and exhortations to tidy up leave the underlying processing and belief patterns untouched (Frost & Hartl, 1996).

Hoarding and collecting are the same thing.

A collection is organized, bounded, displayed, and a source of pleasure; hoarded accumulation is indiscriminate, chaotic, and driven by anxiety about loss. The emotional tone and the organization both differ (Nordsletten & Mataix-Cols, 2012).

Hoarding is a form of obsessive-compulsive disorder.

Hoarding was grouped with OCD for decades, but the DSM-5 separated it in 2013. Most people who hoard do not have the intrusive obsessions and ritualized compulsions that define OCD, and the keeping is not experienced as an unwanted ritual but as a reasonable response to the value of the objects (Mataix-Cols et al., 2010).

Simply clearing out the house solves the problem.

Forced cleanouts, without the cognitive and behavioral work, typically precede rapid re-accumulation and can be deeply traumatic. The accumulation returns because the decision-making and belief patterns that produced it are unchanged (Steketee & Frost, 2003).

Glossary

Acquisition.

The obtaining of possessions, by purchase, by collection of free items, or by other means; one of the three defining components of hoarding.

Categorization.

The cognitive operation of grouping objects under general rules; in hoarding, possessions are experienced as unique and non-substitutable, so each is judged individually and sorting becomes unmanageable.

Clutter Image Rating.

A standardized measure in which a person matches their room to one of nine graded photographs, anchoring clutter severity to images rather than to subjective adjectives.

Clutter.

A disorganized accumulation of possessions that fills and defeats the intended use of a living space; the visible, measurable consequence of high acquisition and low discarding.

Cognitive-behavioral model.

The account, due to Frost and Hartl, that explains hoarding through information-processing deficits, beliefs that inflate the value of possessions, and the negative reinforcement of avoidance.

Collecting.

The organized, bounded, pleasurable accumulation of themed objects; distinguished from hoarding by its selectivity, its display rather than piling, and its emotional tone of pleasure rather than anxiety.

Difficulty discarding.

The distress-driven avoidance of parting with possessions regardless of their actual value; one of the three defining components of hoarding.

Emotional attachment.

The sentimental or identity-based bond to a possession that makes its loss feel like a personal injury, giving the discard decision its emotional weight.

Hoarding disorder.

The clinical diagnosis, added to the DSM-5 in 2013, applied when hoarding behavior causes clinically significant distress or impairment; distinct from the behavior itself and from obsessive-compulsive disorder.

Hoarding Rating Scale-Interview.

A brief five-item clinician interview covering clutter, difficulty discarding, acquisition, distress, and impairment, designed for quick administration and tracking change over treatment.

Hoarding.

The persistent acquisition of and failure to discard possessions to the point that clutter defeats the intended use of living spaces; the behavior this article describes.

Information-processing deficit.

A measurable difficulty in a basic cognitive operation — here attention, categorization, memory confidence, or decision making — that the model holds responsible for hoarding behavior.

Negative reinforcement.

The strengthening of a behavior by the removal of an aversive state; here, keeping an object removes the distress of discarding, which makes keeping more likely in future.

Saving Inventory-Revised.

A self-report questionnaire that scores the three components of hoarding — acquisition, difficulty discarding, and clutter — separately.

Saving.

The selective, instrumental keeping of objects with a foreseeable use, discarded without undue distress when that use passes; normal saving is distinguished from hoarding by this selectivity and low distress.

Key Researchers

Catherine R. Ayers

(University of California San Diego and VA San Diego; living). Leads research on hoarding in older adults and on cognitive-rehabilitation approaches to its treatment. Faculty profile

Randy O. Frost

(Smith College; living). Co-originator of the cognitive-behavioral model of hoarding and of its principal assessment instruments; the central figure in establishing hoarding as a distinct research subject. Faculty profile

David Mataix-Cols

(Karolinska Institutet; living). Established the diagnostic boundaries of hoarding and its population prevalence, and helped separate it from obsessive-compulsive disorder in the DSM-5. Faculty profile

Sanjaya Saxena

(San Diego Center for Obsessive-Compulsive and Related Disorders; living). Pioneered the functional-neuroimaging study of hoarding and of the obsessive-compulsive spectrum. Google Scholar

Gail Steketee

(Boston University School of Social Work; living). Developed and tested the cognitive-behavioral treatment of hoarding and of obsessive-compulsive spectrum disorders; longtime collaborator on the model and its therapy. Faculty profile

David F. Tolin

(Institute of Living and Yale University School of Medicine; living). Developed the Hoarding Rating Scale and led the meta-analysis of cognitive-behavioral therapy for hoarding. Wikipedia

Frequently Asked Questions

What is the difference between hoarding and collecting?

Collecting is organized, bounded, and pleasurable: a collection is curated around a theme, displayed, and the collector can say why each item belongs. Hoarding accumulation is indiscriminate and chaotic, stored in piles rather than displayed, and driven by anxiety about loss rather than pleasure in possession. The organization and the emotional tone both differ.

Is hoarding a type of obsessive-compulsive disorder?

No. Hoarding was grouped with OCD for decades, but the DSM-5 recognized hoarding disorder as a separate diagnosis in 2013. Most people who hoard do not have the intrusive obsessions and ritualized compulsions that define OCD, and the keeping is experienced as a reasonable response to the value of objects rather than as an unwanted compulsion.

Why can't someone who hoards just throw things away?

Because discarding provokes genuine distress, and avoiding that distress by keeping the object is negatively reinforced each time it happens, making keeping increasingly automatic. The difficulty is a problem of decision making, categorization, and emotional attachment, not of effort, so advice to discard everything at once targets the behavior while leaving its causes untouched.

How common is hoarding?

A systematic review and meta-analysis estimates that clinically significant hoarding affects roughly 2.5% of the population, comparable to other common mental conditions and higher than once assumed. Prevalence also rises with age.

How is hoarding measured?

With standardized instruments: the Saving Inventory-Revised scores acquisition, difficulty discarding, and clutter separately; the Hoarding Rating Scale-Interview is a brief clinician interview; and the Clutter Image Rating anchors clutter severity to a series of graded photographs, which reduces under-reporting.

Does hoarding run in families?

Hoarding tends to cluster in families and has a substantial heritable component, though the behavior that results from any genetic predisposition is shaped by learning and experience. The cognitive-behavioral model describes the processing and belief mechanisms through which a predisposition becomes the behavior, whatever its origin.

Can hoarding be treated?

Yes, though incompletely. Cognitive-behavioral therapy adapted specifically for hoarding produces reliable moderate improvement in clutter, discarding, and acquisition, with difficulty discarding responding best. Many people retain some symptoms after treatment, so hoarding is considered relatively treatment-refractory, and better interventions are an active research goal.

Is hoarding the same as the clinical diagnosis of hoarding disorder?

Not quite. Hoarding is a behavior that exists on a continuum from mild to severe; hoarding disorder is the diagnosis applied when that behavior reaches the point of significant distress or impairment. The behavior is common and usually non-clinical; the disorder is its disabling extreme, and the diagnostic threshold is deliberately high.

References