Hoarding disorder: a review

Abstract

Hoarding disorder can be defined as a persistent difficulty in discarding items, due to distress associated with such disposal or a perceived need to save items regardless of their actual value. Such behavior must result in the accumulation of clutter, which significantly compromises living conditions, causing distress and/or functional impairment. The most frequently hoarded items are objects and animals. The point prevalence of clinically significant hoarding was estimated to be 1.5 to 2.1% in the general population, and may exceed 6% in the elderly. HD poses a range of health and safety hazards to individuals, especially older adults, generating significant costs to society. The diagnosis of HD is clinical, and should only be established after general medical conditions and other mental disorders that can lead to accumulating behavior have been ruled out. HD appears to follow a chronic, progressive course, and is commonly associated with psychiatric comorbidities. Studies indicate that genetic, familial, cognitive, and traumatic factors are implicated in the etiology of HD. To date, psychotherapies have been the most widely studied therapeutic approaches, but the results of these studies show small effects. Research into pharmacological approaches to HD is still incipient, precluding any conclusions of efficacy.
KEYWORDS: hoarding disorder; collecting; psychopathology.

Full text

Geriatr Gerontol Aging. 2018;12(1):54-6454
REVIEW ARTICLE
aInstituto de Previdência dos Servidores do Estado de Minas Gerais (IPSEMG) – Belo Horizonte (MG), Brazil.
bFaculdade de Saúde e Ecologia Humana (FASEH) – Vespasiano (MG), Brazil.
Correspondence data
Bárbara Perdigão Stumpf – Rua Ceará, 195 – Santa Egênia – CEP: 30150-310 – Belo Horizonte (MG), Brazil – E-mail: bperdigao73@yahoo.com.br
Received on: 01/13/2018. Accepted on: 03/12/2018
DOI: 10.5327/Z2447-211520181800005
HOARDINGDISORDER: AREVIEW
Transtorno de acumulação: uma revisão
Bárbara Perdigão Stumpfa, Cláudia Harab, Fábio Lopes Rochaa
RESUMO
O transtorno de acumulação (TA) pode ser denido como uma diculdade persistente de desfazer-se de itens devido ao sofrimento
associado com o descarte ou uma necessidade percebida de guardar posses a despeito de seu valor real. Tal comportamento
pode resultar no acúmulo de objetos, o que compromete signicativamente o uso da moradia, causando sofrimento e/ou
prejuízo funcional. Os itens acumulados mais frequentemente são objetos e animais. A prevalência do transtorno é de 1,5 a
2,1% na população em geral, podendo ser maior que 6% em idosos. O TA causa riscos à saúde e à segurança dos indivíduos,
especialmente dos idosos, gerando um custo relevante para a sociedade. O diagnóstico de TA é clínico e só deve ser feito
após a exclusão de condições médicas gerais e outros transtornos mentais que podem levar ao acúmulo de objetos. O TA
parece ser um transtorno de curso crônico e progressivo, comumente associado a comorbidades psiquiátricas. Estudos indicam
a participação de fatores genéticos, familiares, cognitivos e de experiências traumáticas na etiologia do TA. A abordagem
terapêutica mais estudada até o momento foram as psicoterapias, mas os resultados mostram efeito pequeno. Os estudos
farmacológicos existentes são muito incipientes, não permitindo conclusões de ecácia.
PALAVRAS-CHAVE: transtorno de acumulação; colecionismo; psicopatologia.
ABSTRACT
Hoarding disorder can be dened as a persistent diculty in discarding items, due to distress associated with such disposal
or a perceived need to save items regardless of their actual value. Such behavior must result in the accumulation of clutter,
which signicantly compromises living conditions, causing distress and/or functional impairment. The most frequently hoarded
items are objects and animals. The point prevalence of clinically signicant hoarding was estimated to be 1.5 to 2.1% in the
general population, and may exceed 6% in the elderly. HD poses a range of health and safety hazards to individuals, especially
older adults, generating signicant costs to society. The diagnosis of HD is clinical, and should only be established aer general
medical conditions and other mental disorders that can lead to accumulating behavior have been ruled out. HD appears to
follow a chronic, progressive course, and is commonly associated with psychiatric comorbidities. Studies indicate that genetic,
familial, cognitive, and traumatic factors are implicated in the etiology of HD. To date, psychotherapies have been the most
widely studied therapeutic approaches, but the results of these studies show small eects. Research into pharmacological
approaches to HD is still incipient, precluding any conclusions of ecacy.
KEYWORDS: hoarding disorder; collecting; psychopathology.

Stumpf BP, Hara C, Rocha FL
Geriatr Gerontol Aging. 2018;12(1):54-64 55
INTRODUCTION
The act of hoarding is not a behavior confined to
humans. No other species, however, fills their lives
with objects as human beings do. People are capable
of creating attachments and even intimacy with inan-
imate objects.1
e concept of possession of objects as if “part of our-
selves” is established around the age of two. roughout
childhood, intense relationships with one particular object
can develop. In the rst half of adolescence, possessions
start to become a sort of “crutch” for the self. During the
second half, they become a reection of who and what we
are, which persists into adulthood. In old age, our posses-
sions become mementos of life; an aid to reection and
nostalgia, as well as a source of comfort. Most of the time,
this is part of the healthy aging process. In a way, our rela-
tionships with objects can be dened as a reection of our
interpersonal relationships.1
Hoarding disorder (HD) can be dened as a persistent
diculty in discarding items, due to distress associated
with such disposal or to a perceived need to save items
regardless of their actual value. is diculty in discard-
ing items can result in clutter, in which hoarded items
ll up living spaces and signicantly jeopardize housing
conditions. For accumulating behavior to be classied as
hoarding, it must cause distress or functional impairment
and cannot be attributable to another clinical illness or
psychiatric disorder.2
The items most often hoarded are objects (e.g., clothes,
papers, books, empty food packaging) and animals.
Difficulty organizing the home, the shame brought on
by messiness or clutter, and criticism from others makes
hoarders commonly isolate from social interaction.3
Thissocial withdrawal, in turn, facilitates increased hoard-
ing. HD poses a wide range of risks to the health and
safety of individuals, especially older adults, as it leads
to poor hygiene, animal infestation, and increased risk of
falls, serious injury, and even death (by burial under “ava-
lanches” of collapsing piles of objects or in house fires).
Inaddition, the disorder causes distress to the affected
individual himself, his family, and the community in which
he lives. Hoardersalso constitute a significant economic
burden, including expenses for fire and rescue services,
health and social services, as well as unemployment and
disability benefits.3
e clinical relevance of HD increases as individuals
age.4,5 Elderly individuals with hoarding behavior constitute
a highly vulnerable population, with a 5-year mortality rate
of approximately 50%.5 However, even in older adults with
a history of psychiatric treatment, HD is usually underdi-
agnosed and untreated. us, it is imperative that health
professionals, especially those who care for the elderly, be
familiar with the symptoms of HD and evaluate properly
for this disorder.4.5
Within this context, the objective of this article is to
present a narrative review of HD.
History
Interest in the phenomenon of hoarding began in the
20th century, alongside the expansion of the psychoana-
lytic movement. In 1908, Freud detailed the so-called “anal
character” as a combination of three peculiarities: order-
liness, obstinacy, and parsimony (which could reach “the
point of avarice”). More specically, Freud’s description
of parsimony was probably one of the earliest sketches of
what would later be called hoarding. In 1912, Jones iden-
tied two key aspects of Freud’s anal trait of parsimony:
the “refusal to give” and “the desire to gather, collect, and
hoard.” Jones suggested that money, books, time, food, and
other objects were fecal equivalents of the anal character.
Later, hoarded possessions were also conceptualized as
phallic symbols, transitional objects, a pathological way
of relating, and as the last vestiges of patients’ object rela-
tions, among others.6
e term “hoarding” was introduced into the scientic
terminology to describe the food-collecting behavior of
certain animals, especially rodents.6 It was rst applied to
humans in a 1966 scientic paper, referring to the extreme
end of a continuum of accumulating behavior.7 Subsequently,
hoarding has been reported in a number of psychiatric dis-
orders, raising questions about how best to classify such
behavior. In the late 1980s, Greenberg described several
psychopathological aspects seen in primary hoarding: early
onset (in the third decade of life), preoccupation with accu-
mulation to the exclusion of work and family, poor insight,
little interest in receiving treatment, and no attempt to
curb the compulsion.6 In the following decade, Frost and
Hartl recognized HD as a disorder they called “compul-
sive hoarding”, a term no longer in use. eircriteria for
compulsive hoarding were:
1. the acquisition of, and diculty discarding, large
numbers of possessions that appear to be useless or
of limited value;
2. living spaces sufficiently cluttered so as to pre-
clude the activities for which those spaces were
designed; and
3. signicant distress or functional impairment caused
by the hoarding.8

Hoarding disorder
Geriatr Gerontol Aging. 2018;12(1):54-6456
Diagnosis
Until the 4th revised edition of the Diagnostic and
Statistical Manual of Mental Disorders (DSM-IV-TR),
hoarding was classified as a symptom of Obsessive-
Compulsive Personality Disorder (OCPD), and indi-
rectly related to Obsessive-Compulsive Disorder (OCD).7
InDSM-5, Hoarding Disorder was classied as an inde-
pendent disorder. e DSM-5 diagnostic criteria2 are
described in Chart 1.
In the 10th revision of the International Classication
of Diseases (ICD-10), hoarding is not mentioned at all,
whether as symptom or as syndrome, dependent or inde-
pendent of other diagnoses.6 However, it is believed that,
like DSM-5, the 11th revision (ICD-11) will have a
chapter on OCD and related disorders, which is expected
to include HD.6.7
Differential diagnosis
Cluttered living spaces are not always pathogno-
monic of HD. A diagnosis of HD can only be estab-
lished after other clinical conditions (e.g., brain tumor,
cerebrovascular disease, Prader-Willi syndrome) and
mental disorders (e.g., OCD, autism, depression, schizo-
phrenia) that can lead to accumulating behavior have
been ruled out. Themain differential diagnoses of HD
are described below.
Normative collecting
HD must be dierentiated from normative collect-
ing.7-10 e habit of acquiring and accumulating objects of
a specic type (e.g., stamps, coins, objets d’art) is commonly
known as collecting. Collectors are usually methodical
individuals who organize, clean, and catalog their items.
More than 50% of school-age children keep collections,
and many retain the habit into adulthood. Among adults,
about 30% engage in collecting behavior. However, collect-
ing tends to decrease over time, as opposed to hoarding,
which tends to increase with advancing age.1,10 emain
dierences between normative collecting and HD are
presented in Table 1.
“Organic” accumulation
Another dierential diagnosis is so-called “organic” accu-
mulation, also known as “Diogenes syndrome” or “severe
domestic squalor”. is clinical condition, most common
in the elderly, is characterized by a breakdown in and rejec-
tion of social standards, reected by severe self-neglect and
squalor, progressive withdrawal from social contact, reduced
insight into the problem, and accumulating behavior focused
on objects and trash.11,12
A diagnosis of HD is sometimes suggested for hoard-
ers who live in severely unhealthy conditions, surrounded
by garbage, rotten food, and/or excreta. However, domestic
squalor is frequently associated with cases of acquisition/
accumulation secondary to organic pathology; in such cases,
a diagnosis of HD should not be made.7,13 e phenomeno-
logical dierences between “organic” accumulation and HD
are summarized in Table 2.
OCD
To the rst psychoanalysts, “anal traits” (precursors of
what is now termed OCPD) and OCD were part of the
same spectrum, had common etiopathogenetic factors, and
Chart 1 Diagnostic and Statistical Manual of Mental Disorders
(DSM-5) diagnostic criteria for hoarding disorder.
Specify if: With excessive acquisition: If difficulty discarding
possessions is accompanied by excessive acquisition of items that
are not needed or for which there is no available space.
Specify if: With good or fair insight: The individual recognizes
that hoarding-related beliefs and behaviors (pertaining to diculty
discarding items, clutter, or excessive acquisition) are problematic.
With poor insight: The individual is mostly convinced that hoarding-
related beliefs and behaviors (pertaining to diculty discarding
items, clutter, or excessive acquisition) are not problematic despite
evidence to the contrary. With absent insight/delusional beliefs:
The individual is completely convinced that hoarding-related
beliefs and behaviors (pertaining to diculty discarding items,
clutter, or excessive acquisition) are not problematic despite
evidence to the contrary.
Source: APA, 2013.2
A. Persistent diculty discarding or parting with possessions,
regardless of their actual value.
B. This diculty is due to both a perceived need to save the
items and to distress at the thought of discarding them.
C. The diculty in discarding possessions results in the
accumulation of possessions that congest and clutter active living
areas and substantially compromises their intended use. If living
areas are uncluttered, it is only because of the interventions of
third parties (e.g., family members, cleaners, authorities).
D. The hoarding causes clinically signicant distress or
impairment in social, occupational, or other important areas
of functioning (including maintaining a safe environment for
self and others).
E. The hoarding is not attributable to another medical
condition (e.g., brain injury, cerebrovascular disease, Prader-
Willi syndrome).
F. The hoarding is not better explained by the symptoms
of another mental disorder (e.g., obsessions in obsessive-
compulsive disorder, decreased energy in major depressive
disorder, delusions in schizophrenia or another psychotic
disorder, cognitive decits in major neurocognitive disorder,
restricted interests in autism spectrum disorder).

Stumpf BP, Hara C, Rocha FL
Geriatr Gerontol Aging. 2018;12(1):54-64 57
shared a variety of symptoms. As parsimony (or, in recent
parlance, hoarding) is one of the so-called anal traits, it
was believed that hoarding could represent a symptom of
OCD. To these rst theorists, accumulation could take on
the characteristics of a compulsion, dened as a behav-
ior that is recognized by the individual as his or her own,
irresistible, unpleasant, and repetitive. Perhaps as a conse-
quence, hoarding obsessions and compulsions are reported
by almost 53% of patients with OCD.6 However, only a
minority of these individuals (approximately 5%) have this
dimension as the most prominent clinical manifestation of
the disorder. ere are several phenomenological dierences
between accumulating symptoms seen in OCD and those
of HD. For instance:
1. HD-related thoughts differ from OCD-related
thoughts insofar as the former are less intrusive, char-
acterized by poorer insight, associated with pleasure
and reward in most cases, and often unrelated to
other prototypical themes of OCD (obsessions with
aggressive, sexual, religious, contamination-related,
or symmetry-related content);
2. in HD, symptoms are perceived as ego-syntonic,
unlike the obsessions/compulsions of OCD-related
accumulation, which are usually egodystonic;
3. in HD, distress is brought on by clutter, whereas in
OCD, it is the result of intrusiveness;
4. in OCD, thoughts trigger an urgent desire to get rid
of them and/or perform a ritual to relieve them, which
is uncommon in HD; and
5. the reasons for accumulating are dierent in HD
and OCD. In HD, hoarding results from the fear
that items may be needed in future (intrinsic value)
or from a strong emotional attachment to pos-
sessions. In OCD, accumulation aims to alleviate
obsessions, prevent damage caused by aggressive
obsessions or fears of contamination, relieve feelings
of incompleteness, or simply serve as an avoidant
behavior6,7 (Table 3).
Accumulation should only be seen as a symptom of OCD
when it is clearly secondary to typical obsessions. e relation-
ship between obsessive thoughts and the resulting behavior
(accumulation/hoarding) is the same as that between tradi-
tional obsessions and compulsions. Nevertheless, HD and
OCD can coexist in the same patient and be completely
independent conditions.7,9
Epidemiology
Ascertaining the prevalence of HD is no easy task,
as hoarders tend to minimize and be ashamed of their
problem.1 Studies on the prevalence of HD performed
prior to the publication of DSM-5 reported rates around
Feature Normative collecting Hoarding disorder
Content Very focused; objects are bound by a cohesive
theme, with a narrow range of object categories
Unfocused; objects lack a cohesive theme, and
the accumulation contains a large number of
dierent object categories
Acquisition process Structured; planning, searching for items,
organizing the collected items
Unstructured; lack of advance planning, focused
searching, or organization
Excessive acquisition Possible, but uncommon; items primarily
acquired by purchasing
Very common; >80% of items bought or
collected for free
Level of organization High; rooms are functional and collected items are
organized, stored, or displayed in an orderly fashion
Low; the functionality of rooms is compromised
by the presence of clutter
Distress
Rare; for the majority of collectors, the activity
is pleasurable, although for a minority, collecting
may result in distress due to factors other than
clutter (e.g., nances)
Required for diagnosis; distress is oen a
consequence of the presence of excessive
clutter, forced discarding, or inability to acquire
Social impairment
Minimal; collectors have high rates of marriage,
and the majority report engaging in social
relationships as part of their collecting behavior
Oen severe; hoarding disorder is consistently
associated with low rates of marriage and high
rates of relationship conict and social withdrawal
Occupational interference
Rare; scores on objective measures indicate that
collectors do not experience clinically signicant
impairment at work
Common; occupational impairment increases
with hoarding severity; high levels of impairment
at work have been reported
Table 1 Dierences between normative collecting and hoarding disorder.
Source: aer Mataix-Cols, 2014.8

Hoarding disorder
Geriatr Gerontol Aging. 2018;12(1):54-6458
2 to 4%, rising up to 6% in subjects over the age of 55.14-19
Ofthese studies, only one was not conducted in the
Western world.19 In the first epidemiological study to
follow the DSM-5 diagnostic criteria, conducted in the
United Kingdom, the estimated prevalence was 1.5% in
both sexes, with the highest prevalence found in older
adults.20 In a study conducted in the Netherlands, the
prevalence of HD was 2.12% in both sexes, with a linear
rise in prevalence of approximately 20% every 5 years.21
In Brazil, a cross-sectional study carried out in Curitiba
(PR) on the frequency of accumulating behavior showed a
rate of 6.45 hoarders per 100,000 population.22 Thisstudy
estimated a rate of 1 case of compulsive hoarding per
15,503 population, 7,390 men, 8,133 women, 1,753
older adults (over 60 years), 716 elderly men, and 1,037
elderly women. This rate is lower than those reported
in international studies, probably because only hoard-
ers reported to government agencies were included in
the sample. The reduction in prevalence in studies con-
ducted after publication of the DSM-5 is possibly due
to the recent standardization of diagnostic criteria for
HD, especially with the exclusion of cases secondary to
other conditions. In previous studies, authors used their
own definitions of clinically meaningful accumulating
behavior and identified members of populations that
met those criteria.7
“Organic” accumulation Hoarding disorder
Onset Generally sudden in cases of brain damage. Can be
more insidious if secondary to a dementing process
Insidious. Usually starts in childhood/adolescence
and has a long natural history
Ability to discard
hoarded items
Variable (some are able to discard their
possessions easily or do not care if others
discard them, while others are very reluctant)
Inability to discard hoarded items is a core
feature of hoarding disorder
Nature of
acquiring behavior
Generally indiscriminate, but can be more selective
(acquisition of specic items, e.g., umbrellas, or
according to their shape/color) in some cases
Items are always acquired/hoarded according to
their perceived intrinsic, practical, or emotional value,
but can be more indiscriminate in some cases
Utility of hoarding behavior
Oen purposeless (individuals display little or
no interest in the accumulated items) and items
seldom used
More purposeful (items are hoarded for specic
emotional or practical reasons), although items
are oen not used
Hoarded items Any item, including rotten food Any item, although hoarding of rotten food is rare
Squalor and/or self-neglect Frequent (especially in cases of dementia) Thought to be relatively uncommon, although
more research is needed
Associated features
Severe personality changes, as well as behaviors
commonly attributed to brain dysfunction such
as pathological gambling, inappropriate sexual
behavior, compulsive shopping leading to
nancial diculties, the, stereotyping, tics, and
self-injurious behaviors
No severe personality changes or other
behaviors clearly attributable to brain
dysfunction. Excessive acquisition, shopping, and
stealing may be present
Cognitive processes and
motivations for hoarding
Hoarding apparently devoid of identiable
cognitive and emotional processes, although
more research is needed
a) Information processing decits: decision
making, categorization, organization, and
memory diculties; b) emotional attachment
to possessions; c) behavioral avoidance;
d) erroneous beliefs about possessions
Insight and
help-seeking behavior Insight poor or absent. Patients seldom seek help
Insight ranges from good to poor or absent.
Initially, hoarding behavior can be ego-syntonic;
it becomes increasingly distressing as clutter
increases. Help-seeking is probably related to
the degree of insight
Prevalence Unknown (<1%) Approximately 2-5%
Genetic Unknown, but there are anecdotal reports of
relatives independently living in squalor
Yes. Hoarding disorder tends to run in families
and appears to be moderately heritable
Table 2 Phenomenological dierences between accumulating behaviors secondary to macroscopic brain damage in patients
with brain injury or dementia and the accumulating behaviors of hoarding disorder.
Source: aer Snowdon et al., 2012.12

Stumpf BP, Hara C, Rocha FL
Geriatr Gerontol Aging. 2018;12(1):54-64 59
HD appears to follow a chronic, progressive course.
Accumulating behavior typically begins in adolescence, with
a mean age at onset between 11 and 15 years. Initially,symp-
toms do not cause distress or impairment, but usually
become problematic around the fourth or fth decade of
life.9,23,24 e mean age at treatment initiation is approxi-
mately 50 years.24 HD diagnosed later in life tends to be
more severe.5
HD is associated with psychiatric comorbidities,
including high rates of depression, generalized anxiety
disorder (GAD), social phobia, attention decit/hyper-
activity disorder (ADHD), and OCD.5 In older adults
with HD, specically, the most frequent comorbidities
are depression (14–54%), anxiety disorders, personality
disorders, posttraumatic stress disorder, and substance use
disorders.5 In addition, individuals with HD have a worse
overall health status compared to controls, especially in
older populations.24
Etiology
e causes of HD are unknown, but some theories have
been proposed.
Genetics
HD appears to have a strong genetic component.
Familial studies conducted before 2013 showed that
hoarding was more common among rst-degree relatives
of compulsive hoarders compared to controls.25-28 e rst
study conducted after publication of the DSM-5 evalu-
ated symptoms of hoarding among parents and siblings of
patients with a diagnosis of HD, and compared them to
relatives of individuals with OCD and community con-
trols. Participants in the three groups reported a higher
rate of hoarding symptoms among female relatives (moth-
ers and sisters) compared to males (fathers and broth-
ers), and the rates found in relatives of individuals with
HD were higher than those found in the other groups.29
Hoarding disorder Hoarding as a dimension of
obsessive-compulsive disorder
Relationship between hoarding and
obsessive-compulsive symptoms
Hoarding not related to
obsessions/compulsions
Hoarding behavior is driven primarily by
prototypical obsessions or is the result of
persistent avoidance of onerous compulsions
Checking behavior associated with hoarding Rare and mild Frequent and severe
Obsessions related to hoarding
(e.g., catastrophic consequence
or magical thinking)
No Yes
Mental compulsions related to hoarding No Yes
Ego-syntonic/ego-dystonic Usually ego-syntonic: hoarding thoughts are
associated with pleasant feelings of safety
Usually ego-dystonic: intrusive or
unwanted, repetitive thoughts
Presence of obsessive-compulsive
symptoms other than hoarding No Yes
Distress Comes from clutter (product of behavior) Comes from intrusion
Main reason for hoarding Intrinsic and/or sentimental value Other obsessional themes
Type of hoarding
Common items (old clothes, magazines,
CDs, letters, pens, bills, newspapers, etc.) Yes Ye s
Bizarre items (feces, urine, nails, hair,
used diapers, rotten food, etc.) No Yes
Excessive acquisition Usually present Usually absent
Insight Frequently poor or absent Generally good, although
poor insight may be present
Course of hoarding behavior Hoarding tends to increase in
severity as the person ages
Hoarding does not increase in
severity as the person ages (usually)
Global severity/interference Usually moderate Usually severe
Table 3 Characteristics of hoarding in patients with hoarding disorder vs. hoarding secondary to obsessive-compulsive disorder.
Source: Aer Albert et al., 2015.7

Hoarding disorder
Geriatr Gerontol Aging. 2018;12(1):54-6460
Findingsfrom genetic studies are consistent with those
of familial studies, suggesting that accumulating behav-
ior is heritable.30 However, specic genes predisposing to
HD have not been consistently identied.5
Trauma
Individuals with HD often report traumatic life events
preceding or exacerbating the disorder.9,31 Notably, in
elderly hoarders, reported rates of posttraumatic stress
disorder range from 3.5 to 18%.5 Studies have suggested
that certain types of traumatic events have a stronger
association with HD. For instance, interpersonal trau-
mas (such as domestic violence, accidental or tragic loss
of a loved one, or neglect in childhood) are the types of
traumatic event most commonly reported by patients
with HD.32,33 e experience of interpersonal trauma can
result in strong emotional attachment to possessions or
belongings that provide a sense of security. is may be
the reason why patients with HD experience diculty
separating from their belongings and are prone to exces-
sive acquisition.8,34 Furthermore, a perceived threat to their
possessions (e.g., loss of belongings in a re, forced dis-
posal of objects) is commonly reported before the onset
of accumulating symptoms.32,33 One study examined the
relationship between trauma (including physical/sexual
abuse, crime, and disasters in general) and tendencies to
acquisition and hoarding. e authors reported that the
development of HD is also related to the intensity of
the traumatic event, particularly physical/sexual abuse.34
However, there are no prospective studies conrming a
causal relationship.7 Contrary to popular belief, there is
no evidence to support that material deprivation in child-
hood predisposes to HD.9
Cognitive-behavioral model
According to the cognitive-behavioral model pro-
posed by Steketee and Frost, HD develops as a result of
emotional responses associated with certain thoughts
and beliefs about possessions. Individuals find it diffi-
cult to discard possessions, seeking to avoid the anxiety
associated with discarding and decision making, while
positive emotions associated with belongings facilitate
their acquisition and storage.35 Frost and Hartl pro-
posed that three primary factors contribute to accumu-
lating behavior:
1. beliefs related to possessions and excessive emotional
attachment;
2. behavioral avoidance, which develops as a result of
emotional distress associated with discarding items;
3. and information processing decits in attention,
categorization, memory, and decision-making8
(Figure 1).
Research and clinical observation suggest that accumu-
lating behavior in HD serves to avert distress and provide
comfort, which probably perpetuates the disorder through
positive and negative reinforcement. Studies examining
the associations between hoarding, emotion, and mood
have related poor emotional regulation, high comorbid-
ity with depression, and low distress tolerance to excessive
acquisition and diculty discarding. While this evidence
supports the proposition that hoarding behaviors can be
driven by emotional diculties, the mechanisms whereby
some components of the current model contribute to such
behaviors are unclear.36
Clinical features
As mentioned above, accumulating behaviors typ-
ically begin in early adolescence and tend to become
more severe over the years.9,24,37,38 When HD is sub-
divided into its main symptoms of clutter, acquisition,
and difficulty discarding, acquisition (whether through
purchase, “picking”/collecting, or even stealing) appears
to start later than the other symptoms. One possible
explanation is the greater physical and financial inde-
pendence of individuals as they reach adulthood.37
Symptomsbegin to interfere with functioning around
the age of 25, and significant impairment is observed
around the age of 35 years.9
HD is associated with signicant functional impair-
ment for both patients and families. One study showed
that the level of carer overload experienced by relatives of
patients with HD was comparable to or even higher than
that reported in the literature by relatives of individuals
with dementia.39
Individuals can hoard objects, animals, and even
electronic information. Animal hoarding in particular
is characterized by accumulation of animals without
providing proper care and an adequate environment, as
well as health and safety risks and impairment of occu-
pational and social functioning. The houses of animal
hoarders are cluttered, disorganized, and dysfunctional.
Squalor is frequent, urine and feces are commonly found
in living areas, and animal cadavers may be present.
Thesehoarders have great difficulty giving up their ani-
mals to people who are able to care for them properly,
and develop intense attachments that result in signifi-
cant impairment.40

Stumpf BP, Hara C, Rocha FL
Geriatr Gerontol Aging. 2018;12(1):54-64 61
Vulnerability factors Beliefs/emotional attachment Emotional reactions Hoarding behaviors
Information processing
Perception
Attention
Memory
Categorization
Decision-making
Early experiences
Core beliefs
Unworthy
Unlovable
Abandoned
Personality
Perfectionism
Dependency
Paranoia
Mood
Depression
Anxiety
Comorbidity
Social phobia
Trauma
Beliefs about possessions
Utility
Intrinsic beauty
Sentimental value
Beliefs about vulnerability
Safety/comfort
Loss
Beliefs about responsibility
Waste
Lost opportunity
Beliefs about memory
Mistake/misunderstanding
Lost information
Beliefs about control
Positive emotions
Pleasure
Pride
Negative emotions
Sadness
Anxiety/fear
Guilt/shame
Clutter
Acquiring
Difficulty in
discarding
Figure 1 Cognitive-behavioral model of hoarding disorder.
Source: Steketee & Frost (2006).35
Assessment
Individuals with HD usually present to health services
brought by other persons or government agencies that have
identi ed the problem; spontaneous help-seeking is rare.
 e diagnosis of HD is clinical. Tests are ordered solely
to rule out organic diseases that may be responsible for
accumulating behavior. Several diagnostic instruments can
assist in the diagnosis of HD, such as the Saving Inventory
Revised (SI-R), UCLA Hoarding Severity Scale (UHSS),
Hoarding Rating Scale-Interview (HRS), and Structured
Interview for Hoarding Disorder (SIHD).41-44 To the best
of our knowledge, only the SI-R has been validated for
use in Brazil.45
During the interview, it is important to probe patients
for symptoms of hoarding, as spontaneous reporting is
unusual. Patients with HD display varying degrees of
insight. They are usually ashamed of their own homes
due to clutter, and have probably received much criticism
over the years. The formal diagnosis requires an interview
conducted by a trained health professional, preferably at
the patient’s home, as the presence of clutter is neces-
sary for diagnosis. The home visit allows the clinician to
objectively assess the proportion of the disorder, ascertain
the extent of the resulting clutter and impairment, and
determine whether health and safety risks are present.
If a home visit is impossible, the use of photographs or
even video footage to evaluate the extent of the prob-
lem is advised. However, it bears stressing that neither a
home visit nor the use of photographs/video can replace
a thorough psychopathological interview. Inpatients
with poor or even absent insight, which constitute the
majority of cases, an interview should be conducted with
reliable informants.7,9 A study evaluating the accuracy
of reports of symptom severity and degree of insight in
HD showed good correspondence between the reports
of patients and those of informants regarding the sever-
ity of clutter, but informants reported higher degrees
of squalor. Comparisons between reports of informants
and professionals have shown that informants underes-
timate the insight of individuals with HD. Patients with
HD who refused to participate in the study had greater
symptom severity and less insight compared to those
who participated.46
Treatment
The unsatisfactory response of accumulating behav-
iors to standard treatments for OCD has led to the
development of specific approaches to this problem.
Early treatments were based on the cognitive-behavioral
model of compulsive hoarding, and included training in

Hoarding disorder
Geriatr Gerontol Aging. 2018;12(1):54-6462
decision-making and categorization, exposure to dis-
carding, and cognitive restructuring of irrational beliefs
associated with hoarding.47
Various protocols for individual cognitive-behav-
ioral therapy (CBT), group CBT, and self-help treat-
ments were developed for HD. More recently, other
approaches have been tested, such as harm reduction
(for individuals who are not motivated to change their
accumulating behavior), cognitive remediation ther-
apy directed at neurocognitive deficits, family-based
interventions to increase the motivation of individu-
als with HD and/or support the needs of relatives, and
pharmacotherapy.47-49
Psychotherapy
To the best of our knowledge, four reviews on the psy-
chotherapeutic treatment of hoarding difficulties have
been published.47,50-52 In two, the authors found mod-
est responses and high discontinuation rates with treat-
ments not specific for hoarding in patients with OCD
and hoarding symptoms, compared to those without
hoarding symptoms.50,52 A meta-analysis by Tolin et al.
showed a significant reduction in the severity of hoard-
ing after HD-specific CBT interventions. The largest
effects were seen for difficulty discarding, followed by
clutter and acquisition. The rates of clinically signifi-
cant improvement, however, were low (24–43%), as was
improvement in functional impairment.51 The most recent
review included 20 studies and assessed the quality of evi-
dence regarding treatments for HD symptoms and related
problems. Thetreatment approaches evaluated were CBT,
pharmacotherapy, cognitive rehabilitation, online support,
and family interventions. Most of the included studies
(n=17/20) were of CBT-based interventions. Althoughthe
majority of the studies were of poor methodological qual-
ity, the results obtained with CBT strategies (individual,
group, and bibliotherapy support groups) were compara-
ble. However, the reductions in symptom severity were
modest. Cognitive remediation, despite little research to
support it, improved hoarding symptoms by up to 40%.
The authors concluded that no psychosocial technique
for HD is superior to others, although the most reliable
evidence to date is for individual or group CBT follow-
ing an HD-specific protocol.47
Studies of psychotherapeutic treatment of HD in the
elderly are particularly scarce. Research on the use of
CBT for late-life hoarding is limited to case reports and
open trials.53
Pharmacological treatment
To date, there has been little research into pharma-
cological treatment of HD. To our knowledge, there
are only four published studies on pharmacotherapy for
this disorder,42,54-56 only one of which included elderly
patients.55 The first study evaluated the efficacy of par-
oxetine in 79 subjects with OCD for 12 weeks (mean
dose 41.6 ± 12.8 mg/day). Of these, 32 were compul-
sive hoarders. Both compulsive hoarders and patients
with OCD without hoarding symptoms improved with
treatment. Accumulating behaviors improved, as did
other symptoms of OCD (mean reduction, 24%), as
measured by the UHSS. However, paroxetine was poorly
tolerated. Only 16 of the 79 patients tolerated a dose
of 60 mg/day. Less than half of the sample reached a
dose of 40 mg/day, and 12 patients were unable to tol-
erate more than 30 mg/day. The most common adverse
effects were sedation, fatigue, constipation, headache,
and sexual dysfunction.42
Another study evaluated the efficacy of venlafaxine
in the treatment of 24 subjects with HD for 12 weeks
(mean dose 204 ± 72 mg/day). e symptoms of hoard-
ing improved, with a mean reduction in UHSS score of
36%. Overall,96% of participants (n=23/24) completed
the study, and no patient discontinued treatment due to
adverse eects or lack of ecacy. Twelve of the 23 partici-
pants tolerated at least 150 mg/day of venlafaxine, 16 tol-
erated 225 mg/day, and four received the maximum dose
of 300 mg/day. However, the authors reported a signicant
negative correlation between age and treatment response,
suggesting that older patients experienced fewer reductions
in hoarding symptoms.55
In a case series, four patients with HD without
comorbid ADHD were treated with controlled-release
methylphenidate for 4 weeks (mean dose 50 ± 9 mg/
day). Twoparticipants displayed a modest reduction in
hoarding symptoms measured by the SI-R (25 and 32%),
especially regarding excessive acquisition. There were no
treatment-emergent symptoms such as tics, psychosis,
mania, or depression. However, at the end of the study, no
participant agreed to continue treatment, due to adverse
effects (insomnia and palpitations).54 More recently, one
study evaluated the efficacy of atomoxetine for 12 weeks
(40–80 mg/day) in the treatment of 12 patients with HD.
The mean reduction in hoarding symptoms was 41.3%
(UHSS-measured).56
Regarding the acceptability of treatments and services
available to individuals with HD, a recent study showed

Stumpf BP, Hara C, Rocha FL
Geriatr Gerontol Aging. 2018;12(1):54-64 63
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that the treatments deemed most acceptable by patients
were individual CBT, professional organizing services,
and self-help books. e least acceptable treatments were
medication, cleaning and removal services, and a court-ap-
pointed guardian.57
CONCLUSION
HD is a serious, under-researched mental disorder,
with a prevalence of 1.5 to 2.1% in the general popu-
lation, possibly rising to 6% in the elderly. Its course is
chronic and progressive. HD was recently included in the
DSM-5 as an independent nosological entity. It entails
significant costs to society, because of the risks it poses
to the health and safety of individuals, especially older
adults. Studies indicate that genetic, familial, cognitive,
and traumatic factors are implicated in the etiology of
HD. To date, psychotherapies have been the most widely
studied therapeutic approach, but the results of these
studies show small effects. Research into pharmacolog-
ical approaches to HD is still incipient, precluding any
conclusions of efficacy.
CONFLICTOFINTERESTS
e authors declare no conict of interests.

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