Recent Advances in
Sanjaya Saxena, MD
Sanjaya Saxena, MD
Department of Psychiatry, University of California at San Diego,
8950 Villa La Jolla Village Drive, Suite C-207, San Diego,
CA 92037, USA.
Current Psychiatry Reports 2008, 10: 297– 303
Current Medicine Group LLC ISSN 1523-3812
Copyright © 2008 by Current Medicine Group LLC
Compulsive hoarding is a common and often disabling
neuropsychiatric disorder. This article reviews the con-
ceptualization, phenomenology, diagnosis, etiology,
neurobiology, and treatment of compulsive hoard-
ing. Compulsive hoarding is part of a discrete clinical
syndrome that includes diffi culty discarding, urges to
save, excessive acquisition, indecisiveness, perfection-
ism, procrastination, disorganization, and avoidance. It
was thought to be part of obsessive-compulsive disor-
der or obsessive-compulsive personality disorder, but
recent evidence indicates that it should be classifi ed
as a separate disorder with its own diagnostic criteria.
Compulsive hoarding is a genetically discrete, strongly
heritable phenotype. Neuroimaging and neuropsy-
chological studies are elucidating its neurobiology,
implicating dysfunction of ventral and medial prefrontal
cortical areas that mediate decision-making, attention,
and emotional regulation. Effective treatments include
pharmacotherapy and cognitive-behavioral therapy.
More research will be required to determine the preva-
lence, etiology, and pathophysiology of compulsive
hoarding and to develop better treatments.
Hoarding is defi ned as the acquisition of and inability to
discard items even though they appear (to others) to have
no value [ 1 ]. Hoarding behavior has been observed in
several neuropsychiatric disorders, including schizophre-
nia, dementia, autism, and mental retardation, as well as
in nonclinical populations [ 2 ], but it is most commonly
associated with obsessive-compulsive disorder (OCD).
Approximately 18% to 42% of patients with OCD have
hoarding and saving symptoms [ 2 , 3 , 4• ].
Although standard diagnostic classifi cations consider
OCD to be a single diagnostic entity, factor analyses of
OCD symptoms have consistently identifi ed at least four
principal symptom factors: 1) aggressive, harm-related,
sexual, and religious obsessions with checking compul-
sions; 2) symmetry and order obsessions with arranging,
repeating, and counting compulsions; 3) contamination
obsessions with washing and cleaning compulsions; and
4) compulsive hoarding and saving symptoms [ 5 , 6 ]. These
symptom factors appear to be relatively stable over time
and show different patterns of genetic inheritance, comor-
bidity, and treatment response [ 6 ]. Cluster analyses,
which identify mutually exclusive, categorical subgroups,
indicate that some of these symptom factors, including
hoarding, may constitute discrete subtypes of OCD [ 7 ].
The hoarding symptom factor has been identifi ed in
phenomenologic and epidemiologic studies of OCD in
the United States, Brazil, Canada, Costa Rica, France,
Germany, Italy, Japan, the Netherlands, Poland, Turkey,
Egypt, Singapore, and South Africa, where it is found in
both blacks and whites [ 6 , 8 ]. Thus, compulsive hoarding
is not a culture-bound syndrome.
The Compulsive Hoarding Syndrome
Frost and Hartl [ 9 ] developed the fi rst systematic defi nition
and diagnostic criteria for clinically signifi cant compulsive
hoarding: 1) the acquisition of and failure to discard a large
number of possessions that appear (to others) to be useless
or of limited value, 2) living or work spaces suffi ciently
cluttered so as to preclude activities for which those spaces
were designed, and 3) signifi cant distress or impairment
in functioning caused by the hoarding behavior or clutter.
They found that hoarding and saving symptoms are part
of a discrete clinical syndrome that includes the core symp-
toms of urges to save, diffi culty discarding, and excessive
acquisition but also indecisiveness, perfectionism, procras-
tination, disorganization, and avoidance [ 2 ]. In addition,
many compulsive hoarders are slow to complete tasks, are
frequently late for appointments, and display circumstan-
tial and overinclusive language. Patients with prominent
hoarding and saving symptoms who display these other
associated symptoms thus are considered to have the com-
pulsive hoarding syndrome [ 2 , 10 ].
298 Anxiety Disorders
Compulsive hoarding is most commonly driven by
obsessional fears of losing important items that the patient
believes will be needed later or making the “wrong” deci-
sion about what to keep and what to discard. These fears
cause substantial distress and lead to compulsions to acquire
and save items to prepare for every imaginable contingency.
Hoarders also frequently have excessive emotional attach-
ments to possessions and distorted beliefs about possessions’
importance [ 1 ], leading to excessive saving. The consequent
clutter can cause signifi cant social and occupational impair-
ment [ 2 , 10 ]. In severe cases, it can produce health risks from
infestations, falls, fi res, and inability to cook or eat in the
home [ 2 ]. Avoidance is prominent and includes behavioral
avoidance of discarding items, putting things away, or clean-
ing, as well as cognitive avoidance of making decisions or
even thinking about the clutter or its consequences.
The mean age at onset of compulsive hoarding symp-
toms is 12 to 13 years [ 11• , 12 , 13 ]. Diffi culty discarding and
clutter usually precede excessive acquiring [ 11• ]. Symptoms
generally worsen from mild during the teenage years to mod-
erate when patients are in their 20s to severe when they are
in their 30s. Recognition of symptoms develops last, gener-
ally not until patients reach their 30s and 40s [ 11• ].
Diagnostic Classifi cation of Compulsive
Relationship of compulsive hoarding to OCD
Although compulsive hoarding long has been considered a
subtype or symptom factor within OCD, recent evidence
suggests otherwise. Whereas the harm/checking, contami-
nation/cleaning, and symmetry/rituals symptom factors are
strongly intercorrelated, hoarding/saving symptoms do not
correlate strongly with the other major factors in clinical and
nonclinical samples [ 6 , 14 ]. Patients with OCD do not report
more hoarding symptoms than healthy controls or patients
with other disorders [ 14 , 15 ]. Moreover, many compulsive
hoarders have no other OCD symptoms [ 1 , 2 , 14 ]. A recent
taxometric analysis of OCD symptoms found that hoarding
showed signifi cant evidence of taxonicity, indicating that
it constituted a categorical latent subclass; the other OCD
symptoms were found to be dimensional, varying by degrees
along a continuum [ 16•• ]. The taxonic latent structure of
compulsive hoarding indicates that it is a discrete categorical
entity that may have an etiologic mechanism distinct from
that of other OCD symptoms [ 16•• ]. Taken together, these
fi ndings call into question the idea that compulsive hoarding
is simply part of OCD and suggest that it may be a separate
but related OCD spectrum disorder that is frequently comor-
bid with OCD, similar to the way body dysmorphic disorder
and trichotillomania are now conceptualized [ 17 ].
The phenomenology of compulsive hoarding is consistent
with its conceptualization as an OCD spectrum disorder, as
its core features include obsessions, compulsions, and avoid-
ance [ 9 ]. However, compulsive hoarding also has similarities
to impulse control disorders. Many hoarders are prone to
excessive buying, excessive acquisition of free items, and
even shoplifting [ 2 ]. These behaviors are ego-syntonic in
some patients, who derive pleasure from acquisition.
Hoarding versus nonhoarding OCD
OCD patients with hoarding symptoms differ from non-
hoarding OCD patients in many important ways. They
have earlier age at onset but older age when presenting for
treatment [ 2 , 10 ]; greater prevalence of symmetry, order-
ing, counting compulsions, and indecisiveness [ 4• , 12 ]; more
anxiety, depression, schizotypal, and dependent personality
disorder symptoms [ 2 , 4• , 8 , 12 ]; and less insight than non-
hoarding OCD patients [ 4• ]. Child and adolescent OCD
patients with signifi cant hoarding symptoms were found to
have more magical thinking obsessions, ordering/arranging
compulsions, anxiety, aggression, somatic complaints, overall
externalizing and internalizing symptoms, and worse insight
than nonhoarding children with OCD [ 18 ]. Compared with
nonhoarding OCD patients, compulsive hoarders have more
severe family and social disability and lower global function-
ing [ 2 , 10 , 13 ]. Hoarding OCD patients are less likely to be
married [ 12 , 13 ], have signifi cantly lower incomes [ 13 ], and
report signifi cantly more traumatic life events than nonhoard-
ing OCD patients [ 19 ]. They also show a different pattern of
comorbidity than nonhoarding OCD patients, with signifi -
cantly greater prevalence of social phobia, generalized anxiety
disorder, specifi c phobias, bipolar disorder, dysthymia, brief
depression, personality disorders, and pathologic grooming
disorders [ 4• , 9 , 12 , 13 ]. Child and adolescent OCD patients
with signifi cant hoarding symptoms have higher rates of panic
disorder than nonhoarding children with OCD [ 18 ].
Compulsive hoarding versus obsessive-compulsive
Currently, the inability to discard worthless items is listed
in the DSM-IV as a symptom of obsessive-compulsive
personality disorder (OCPD). However, the available evi-
dence argues strongly against classifying hoarding as part
of OCPD. Compulsive hoarders have been found to have
no more OCPD traits than controls [ 2 ], and only a small
percentage of them have comorbid OCPD [ 4• ]. Of the
current diagnostic criteria for OCPD, inability to discard
worthless items has the lowest specifi city, positive predic-
tive value, and total predictive value [ 20 ]. Conversely, it is
the best at discriminating among OCD, panic disorder, and
major depressive disorder diagnoses [ 21 ]. In a student sam-
ple, hoarding severity correlated with scores on an OCD
inventory but not with scores on an OCPD scale [ 1 ]. Taken
together, these fi ndings indicate that hoarding should be
removed from the diagnostic criteria for OCPD [ 17 ].
Family and genetic studies
Compulsive hoarding clearly runs in families. About 84%
to 85% of hoarders report having a fi rst-degree relative
Recent Advances in Compulsive Hoarding Saxena 299
who was a “pack rat,” whereas only 37% to 54% report
having a family member with a different OCD [ 1 , 22 ].
Relatives of hoarding OCD patients have signifi cantly
higher prevalence of hoarding symptoms, dysthymia, and
indecisiveness than relatives of nonhoarding OCD patients
[ 4• , 13 ]. Hoarding symptoms in relatives are related to
indecisiveness in probands, suggesting that indecisive-
ness may be a risk factor for compulsive hoarding. The
hoarding symptom factor is strongly familial, with robust
correlations among sibling pairs [ 23 ], and shows an auto-
somal recessive inheritance pattern [ 4• ].
Only a few genetic studies have examined compul-
sive hoarding. A genome-wide scan in sibling pairs with
Tourette’s syndrome found that the hoarding phenotype
was signifi cantly associated with genetic markers on chro-
mosomes 4, 5, and 17 [ 24 ]. The met/met (L/L) genotype
of the COMT Val158Met polymorphism on chromosome
22q11 was found to be signifi cantly more prevalent in
Afrikaner OCD patients with hoarding symptoms than in
Afrikaner nonhoarding OCD patients or controls [ 8 ]. The
OCD Collaborative Genetics Study found “suggestive”
linkage of compulsive hoarding to a marker on chromo-
some 14 in families with early-onset OCD [ 25•• ]. These
fi ndings indicate that compulsive hoarding is a genetically
Hoarding secondary to brain lesions
There have been several case reports of compulsive
hoarding caused by brain damage. Patients have devel-
oped compulsive hoarding and collecting behaviors after
damage to the orbitofrontal cortex (OFC) and medial
prefrontal cortex (mPFC) caused by cerebral hemorrhage
from ruptured anterior communicating artery aneu-
rysms [ 26 , 27 ], resection of olfactory meningioma [ 28 ],
and frontotemporal dementia [ 29 ]. Anderson et al. [ 30• ]
compared nine patients with compulsive hoarding that
began after brain damage with 54 nonhoarding brain-
damaged patients. All hoarding patients had damage to
the prefrontal cortex, mostly in the medial and inferior
areas. The greatest lesion overlap in hoarders was in the
right mPFC, orbitofrontal pole, anterior cingulate cortex
(ACC), and adjacent white matter. These reports consis-
tently demonstrate that compulsive hoarding can result
from localized damage to the OFC, mPFC, ACC, and
frontal poles. These brain regions mediate performance
on decision-making tests, on which compulsive hoarders
perform worse than nonhoarding OCD patients [ 31• ],
underscoring the fundamental relationship between inde-
cisiveness and compulsive hoarding.
of Compulsive Hoarding
Cerebral glucose metabolism in compulsive hoarding
Our group conducted the fi rst brain imaging study of
compulsive hoarders and found that they had a differ-
ent pattern of baseline cerebral glucose metabolism than
normal controls and nonhoarding OCD patients [ 32 ].
Compulsive hoarders did not have the characteristic
hypermetabolism in the OFC, caudate, and thalamus seen
in nonhoarding OCD patients [ 33 ]. Instead, they showed
signifi cantly lower metabolism in the posterior cingulate
cortex compared with controls. Across all patients stud-
ied, greater hoarding severity was correlated with lower
activity in the dorsal ACC and anterior medial thalamus.
These results suggested that compulsive hoarding was
neurobiologically distinct from OCD [ 32 ]. However, this
study had several limitations that affected its interpret-
ability. Hoarding and nonhoarding OCD patients were
divided retrospectively and were originally recruited and
enrolled based on having OCD, not hoarding symptoms.
Hoarders were signifi cantly older than controls and non-
hoarding OCD patients and had a much higher proportion
of women than nonhoarding OCD patients. Therefore,
we sought to replicate our fi ndings in a new, larger sample
of compulsive hoarders and matched controls, free of the
confounds present in the initial study.
We measured cerebral glucose metabolism with [ 18 F]-
fl uorodeoxyglucose positron emission tomography in
medication-free adults with compulsive hoarding syn-
drome, compared it with that of age- and gender-matched
healthy controls, and found that compulsive hoarders had
signifi cantly lower normalized glucose metabolism in the
bilateral dorsal and ventral ACC than controls (Saxena
et al., unpublished data). Greater hoarding severity was
signifi cantly correlated with lower relative activity in the
right dorsal ACC, right posterior cingulate cortex, and
bilateral putamen. As in our previous study, no differ-
ences were found in brain regions usually associated with
OCD or major depression. Thus, compulsive hoarding
appears to be a neurobiologically distinct disorder with a
unique pattern of abnormal brain function that does not
overlap with that of nonhoarding OCD (Saxena et al.,
These fi ndings have important implications not only for
classifying compulsive hoarding but also its neurobiology
and treatment. The dorsal ACC is involved in decision-mak-
ing, attention, reappraising aversive stimuli, and suppressing
negative affect. Thus, dysfunction of the dorsal ACC may
mediate the diffi culty in making decisions and attentional
problems seen in compulsive hoarders [ 31• , 34 ] and also
could account for hoarders’ inability to control their fears
and distress about losing possessions to which they have
sentimental attachments or that they consider potentially
useful or valuable. Treatments that increase ACC activity,
such as cholinesterase inhibitors, stimulants, or modafi nil,
may be effective for the compulsive hoarding syndrome
(Saxena et al., unpublished data).
Neural correlates of hoarding symptom provocation
Symptom provocation neuroimaging studies reveal patterns
of brain activation occurring as patients actively experience
300 Anxiety Disorders
symptoms. Symptom provocation studies of OCD have
consistently found activation of the OFC, caudate, and
thalamus during the provoked state—usually greater in
patients with OCD than in controls—with less consistent
activation of the ACC and other regions [ 33 ]. However,
only two studies to date have investigated brain activation
during provocation of compulsive hoarding symptoms.
Mataix-Cols and colleagues [ 35 ] provoked hoarding/
saving, contamination/cleaning, and aggressive/check-
ing symptoms in patients with OCD using photographs
intended to provoke specifi c obsessional concerns and
compulsive urges. During the hoarding-related provoca-
tion, patients with OCD showed signifi cantly greater
activation of the left dorsal motor/premotor cortex, right
OFC, and left fusiform gyrus than controls. The degree
of provoked hoarding-related anxiety correlated with the
magnitude of activation of the left dorsal motor/premo-
tor cortex. In contrast, provoked contamination-related
anxiety correlated with activation of different brain
regions—the fusiform and lingual gyri, right superior
temporal gyrus, right inferior frontal gyrus, and right
anterior insula—whereas harm/checking-related anxiety
correlated with activation of the lateral prefrontal cor-
tex, putamen, globus pallidus, and left thalamus [ 35 ].
This study was compromised by the fact that not all the
patients with OCD had the symptoms the investigators
were attempting to provoke, so not all of them became
anxious or symptomatic during the provocation.
The same research group then provoked hoard-
ing/saving symptoms in OCD patients with and without
prominent hoarding symptoms and normal controls by
having them view pictures of commonly hoarded objects
while imagining that these objects belonged to them and
that they “must throw them away forever” [ 36• ]. OCD
patients with prominent hoarding symptoms showed sig-
nifi cantly greater activation of the bilateral frontal pole
and anterior mPFC than nonhoarding OCD patients and
controls and greater cerebellar activation than controls.
Hoarding and nonhoarding OCD patients showed signifi -
cantly less activation of the left OFC than controls. Across
all OCD patients studied, provoked hoarding-related
anxiety correlated with activation of the left ventromedial
PFC, right ventrolateral PFC, bilateral hippocampus and
mesial temporal cortex, right amygdala, left thalamus,
bilateral sensory-motor cortex, and bilateral cerebellum.
Provoked anxiety was negatively correlated with activa-
tion of the left dorsal ACC, bilateral temporal cortex,
dorsolateral PFC, and various parieto-occipital corti-
cal regions. Hyperactivation of the ventromedial PFC, a
region involved in decision-making about potential gains
and losses, may refl ect compulsive hoarders’ greater diffi -
culties in deciding upon the value or importance of objects
they were imagining having to discard, whereas relative
underactivation of the dorsal ACC, dorsolateral PFC, and
parieto-occipital cortex may refl ect defi cient emotional
regulation and planning abilities [ 36• ].
Compulsive hoarders often report problems with atten-
tion and memory and appear to have some neurocognitive
defi cits. Compared with normal controls, compulsive
hoarders had worse delayed visual and verbal recall and
used less effective organizational strategies for visual
recall [ 34 ]. Hoarders also reported signifi cantly less confi -
dence in their memory and more catastrophic assessments
of the consequences of forgetting. In addition, compulsive
hoarders have been found to have slower reaction time,
greater impulsivity, and worse spatial attention than
clinical comparison patients and normal controls [ 37• ].
Hoarding OCD patients reported signifi cantly more dif-
fi culty making decisions than nonhoarding OCD patients
[ 2 , 4• ] or healthy controls, who did not differ from each
other [ 2 ]. OCD patients with prominent hoarding symp-
toms showed impaired decision-making performance
and a qualitatively different pattern of autonomic skin
conductance responses during a gambling task, whereas
low-hoarding or nonhoarding OCD patients showed nor-
mal performance [ 31• ].
Together, the results of neuroimaging and neuropsy-
chological studies demonstrate that the neurobiology of
compulsive hoarding is distinct from that of nonhoard-
ing OCD. The pathophysiology of compulsive hoarding
involves abnormalities in the neural systems mediating
attention, decision-making, and emotional regulation.
Along with genetic fi ndings [ 8 , 25•• ] and the taxometric
study showing that compulsive hoarding is a discrete cat-
egorical entity [ 16•• ], these data suggest that compulsive
hoarding should be classifi ed as a separate disorder with
its own diagnostic criteria in the DSM-V .
Treatment of Compulsive Hoarding
Some, but not all, studies investigating the infl uence
of OCD symptom factors on treatment response have
found that hoarding symptoms were associated with
poor response to pharmacotherapy with serotonin
reuptake inhibitors (SRIs). One small study found that
nonresponders to paroxetine or placebo for OCD were
signifi cantly more likely to have hoarding symptoms than
responders [ 38 ]. In a case series of 18 compulsive hoard-
ers treated openly with a variety of SRIs, only one patient
had an adequate response, eight had partial responses,
and nine had no response [ 22 ]. Higher scores on the
hoarding symptom factor predicted poorer response in an
analysis of placebo-controlled trials of SRI treatment for
OCD patients (after controlling for baseline severity) [ 39 ].
A recent study found that high scores on a hoarding/sym-
metry factor predicted worse outcome in a double-blind
trial of citalopram versus placebo for OCD [ 40 ].
However, several other studies that examined
OCD symptom factors and treatment response did not
confi rm this association. Instead, sexual/religious obses-
Recent Advances in Compulsive Hoarding Saxena 301
sions uniquely predicted poorer long-term outcome
after SRI treatment in one study [ 41 ] and were the only
OCD symptoms that were signifi cantly more common
in treatment-refractory OCD patients than in treatment
responders in another [ 42 ]. Poor insight and somatic
obsessions were signifi cantly more common in non-
responders to SRIs than responders in one study [ 43 ],
whereas sexual obsessions, washing compulsions, and
miscellaneous compulsions predicted nonresponse to
SRIs in another [ 44 ]. These studies all found no signifi -
cant effect of hoarding/saving symptoms on response to
SRI treatment. In addition, a family study that compared
hoarding OCD patients with nonhoarding OCD patients
found that a very similar proportion of patients in the two
groups reported response or remission with SRI treatment
[ 5 ]. Thus, compulsive hoarding does not appear to be a
consistent predictor of poor response to SRI medications.
Only one study to date has prospectively and quantita-
tively measured response to standardized pharmacotherapy
in compulsive hoarders [ 45•• ]. Thirty-two patients with the
compulsive hoarding syndrome and 47 nonhoarding OCD
patients were treated openly with paroxetine monotherapy
(mean dose, 41.6 ± 12.8 mg/d) for 12 weeks. The severity
of compulsive hoarding symptoms was specifi cally quanti-
fi ed before and after treatment using the UCLA Hoarding
Severity Scale [ 45•• ]. Compulsive hoarders responded as
well to paroxetine as nonhoarding OCD patients, with
signifi cant and nearly identical improvements in OCD
symptoms, depression, anxiety, and overall functioning.
A similar proportion of hoarding and nonhoarding OCD
patients were strong responders (28% vs 32%) and partial
responders (22% vs 15%). The proportion of dropouts
was also similar (22% vs 15%). Compulsive hoarders who
completed treatment showed a mean 31% decline in Yale-
Brown Obsessive Compulsive Scale scores. Hoarding/saving
symptoms improved as much as other OCD symptoms. No
correlation was found between hoarding severity and treat-
ment response. These results suggest that SRI medications
are just as effective in compulsive hoarders as they are in
nonhoarding OCD patients [ 45•• ].
Hoarding symptoms have been associated consistently
with poor response and premature dropout from cogni-
tive-behavioral therapy (CBT) for OCD. OCD patients
with prominent hoarding symptoms have been found to
be more likely than nonhoarding OCD patients to drop
out of CBT prematurely [ 46 ], less likely to respond to
outpatient CBT [ 46 , 47 ], and less likely to respond to
intensive inpatient CBT [ 48 ]. Higher scores on the hoard-
ing symptom factor predict premature dropout [ 46 ] and
nonresponse to CBT [ 48 ].
Frost and Hartl [ 9 ] developed a CBT treatment strategy
based on their cognitive-behavioral model of compulsive
hoarding. Their approach includes cognitive restructuring,
decision-making training, and exposure and response pre-
vention involving discarding of saved clutter. They treated
14 unmedicated compulsive hoarders with 26 individual
sessions of CBT—including frequent home visits—over 7
to 12 months [ 49• ]. In the 10 patients who completed treat-
ment, signifi cant pretreatment to post-treatment decreases
were noted in hoarding severity and clutter but not in global
clinical severity. Treatment completers showed a mean 28%
decline in hoarding severity. After treatment, 50% of treat-
ment completers were rated as “much improved” or “very
much improved” [ 49• ].
Our group developed an intensive, multimodal treat-
ment protocol for compulsive hoarding based on Frost
and Hartl’s [ 9 ] model but modifi ed it for use in a short-
term, intensive treatment setting; we broadened it by
including medication treatment, structuring daily activi-
ties, and involving families in treatment [ 10 ]. We studied
190 patients with OCD, 20 of whom had the compulsive
hoarding syndrome. All patients were treated for 6 weeks
in a Partial Hospitalization Program with intensive, daily
CBT; the vast majority received medication. Although
previous trials of SRIs or outpatient CBT had failed in
most of the compulsive hoarders, they showed signifi cant
improvement, with a mean 35% decrease in OCD severity.
A total of 45% of hoarders were classifi ed as responders
to treatment. However, nonhoarding OCD patients had
signifi cantly greater improvement, with a mean 46%
decrease in OCD severity [ 10 ].
Unfortunately, there have been no controlled trials of
pharmacotherapy or CBT for compulsive hoarding. Based
on the open trials summarized previously, it appears that
SRI medications and CBT are effective treatments for
compulsive hoarding, but combined, multimodal treat-
ment is more effective than medication or CBT alone.
The evidence summarized in this article strongly suggests
that compulsive hoarding syndrome is a discrete entity
with a unique profi le of core symptoms, associated fea-
tures, genetic markers, and neurobiologic abnormalities
that differ from those of OCD. Therefore, compulsive
hoarding syndrome should be listed as a separate disorder
in the DSM-V , with its own diagnostic criteria.
There is much we do not know about compulsive
hoarding. No epidemiologic studies of compulsive hoard-
ing exist, so we do not know its prevalence or gender
distribution. However, it is likely to be much more com-
mon than previously thought. No studies have examined
brain structure, neurochemistry, immune function, or
non-SRI medications in compulsive hoarding.
Prior studies of OCD had important fl aws that seri-
ously limited their applicability and usefulness regarding
compulsive hoarding. The DSM-IV criteria for OCD do
not even mention hoarding. Most prior studies of OCD
used diagnostic or screening instruments that excluded
the many patients with compulsive hoarding but no other
302 Anxiety Disorders
OCD symptoms. Many neurobiologic studies of OCD have
not included hoarders. Most treatment studies of OCD
have not focused on treatment of hoarding symptoms. Even
the many studies comparing OCD patients with and with-
out hoarding symptoms examined a phenotype defi ned by
the presence of any hoarding symptoms rather than clini-
cally signifi cant compulsive hoarding. Hence, differences
between groups were likely diluted by the inclusion of
patients in the “hoarding OCD group” who had only mild
hoarding symptoms [ 20 ]. Future studies should examine
the more well-defi ned categorical phenotype of compulsive
hoarding syndrome to improve their chances of identifying
its specifi c genetic and neurobiologic substrates.
Much more research needs to be done to elucidate the
epidemiology, etiology, and pathophysiology of compulsive
hoarding. We must determine its prevalence and gender
ratio in population-based studies, not just in clinical
samples or patients with OCD. We must investigate com-
pulsive hoarding in older adults and determine whether
late-onset hoarding differs from early-onset hoarding. We
must determine what proportion of compulsive hoarders
have structural brain lesions and how they are involved in
the pathophysiology of compulsive hoarding. Neuroimag-
ing studies must identify biologic markers that may aid in
diagnosing compulsive hoarding and providing targets of
treatment. Most importantly, better treatments must be
developed for this common and disabling disorder.
No potential confl ict of interest relevant to this article was reported.
References and Recommended Reading
Papers of particular interest, published recently,
have been highlighted as:
• Of importance
•• Of major importance
1. Frost RO, Gross RC: The hoarding of possessions. Behav
Res Ther 1993, 31: 367– 381.
Steketee G, Frost R: Compulsive hoarding: current status of
the research. Clin Psychol Rev 2003, 23: 905– 927.
Rasmussen S, Eisen JL: The epidemiology and clinical
features of obsessive-compulsive disorder. Psychiatr Clin
North Am 1992, 15: 743– 758.
Samuels JF, Bienvenu OJ 3rd, Pinto A, et al. : Hoarding in
obsessive-compulsive disorder: results from the OCD Collab-
orative Genetics Study. Behav Res Ther 2007, 45: 673– 686.
This study compared 235 hoarding OCD patients with 389 non-
hoarding OCD patients, all participating in the OCD Collaborative
Genetics Study, and found signifi cant differences in symptom
profi le, comorbidity, insight, and family history between the two
groups. It also found a familial relationship between hoarding
and indecision, suggesting that indecision may be a risk factor for
hoarding in these families.
5. Leckman JF, Grice DE, Boardman J, et al. : Symptoms of
obsessive-compulsive disorder. Am J Psychiatry 1997,
154: 911– 917.
6. Mataix-Cols D, Rosario-Campos MC, Leckman JF: A
multidimensional model of obsessive-compulsive disorder.
Am J Psychiatry 2005, 162: 228– 238.
7. Calamari JE, Wiegartz PS, Riemann BC, et al. : Obsessive-
compulsive disorder subtypes: an attempted replication and
extension of a symptom-based taxonomy. Behav Res Ther
2004, 42: 647– 670.
Lochner C, Kinnear CJ, Hemmings SM, et al. : Hoarding
in obsessive-compulsive disorder: clinical and genetic cor-
relates. J Clin Psychiatry 2005, 66: 1155– 1160.
Frost R, Hartl T: A cognitive-behavioral model of compul-
sive hoarding. Behav Res Ther 1996, 34: 341– 350.
Saxena S, Maidment KM, Vapnik T, et al. : Obsessive-
compulsive hoarding: symptom severity and response to
multi-modal treatment. J Clin Psychiatry 2002, 63: 21– 27.
Grisham JR, Frost RO, Steketee G, et al. : Age of onset of
compulsive hoarding. J Anxiety Disord 2006, 20: 675– 686.
This study used retrospective assessment of 51 individuals with com-
pulsive hoarding to determine onset of various hoarding symptoms
(clutter, acquisition, diffi culty discarding) and the individual’s degree
of recognition of the problem. Symptoms of clutter and diffi culty
discarding appeared to begin at the same age (~ 16 years), whereas
acquisition problems began slightly later. Recognition of the problem
developed signifi cantly later than any of the symptoms themselves.
12. Samuels J, Bienvenu OJ, Riddle MA, et al. : Hoarding in
obsessive-compulsive disorder: results from a case-control
study. Behav Res Ther 2002, 40: 517– 528.
13. Wheaton M, Cromer K, Lasalle-Ricci VH, Murphy D:
Characterizing the hoarding phenotype in individuals with
OCD: associations with comorbidity, severity and gender. J
Anxiety Disord 2008, 22: 243– 252.
14. Wu KD, Watson D: Hoarding and its relation to obsessive-
compulsive disorder. Behav Res Ther 2005, 43: 897– 921.
15. Foa EB, Huppert JD, Leiberg S, et al. : The Obsessive-Com-
pulsive Inventory: development and validation of a short
version. Psychol Assess 2002, 14: 485– 496.
16.•• Olatunji BO, Williams BJ, Haslam N, et al. : The latent
structure of obsessive-compulsive symptoms: a taxometric
study. Depress Anxiety 2007 Oct 17 (Epub ahead of print).
In this study, the categorical versus dimensional nature of OCD
symptoms and associated cognitions was examined in a large,
undiagnosed sample using taxometric methods. Six potential OCD
symptoms (washing, checking, obsessing, neutralizing, ordering,
and hoarding) were examined. Findings were largely consistent with
dimensional models of the latent structure of all OCD symptoms and
cognitions with the exception of hoarding, which displayed a taxonic
latent structure, indicating that it is a discrete categorical syndrome.
17. Saxena S: Is compulsive hoarding a genetically and neuro-
biologically discrete syndrome? Implications for diagnostic
classifi cation. Am J Psychiatry 2007, 164: 380– 384.
18. Storch EA, Lack CW, Merlo LJ, et al. : Clinical features
of children and adolescents with obsessive-compulsive
disorder and hoarding symptoms. Compr Psychiatry 2007,
48: 313– 318.
Cromer KR, Schmidt NB, Murphy DL: Do traumatic events
infl uence the clinical expression of compulsive hoarding?
Behav Res Ther 2007, 45: 2581– 2592.
20. Grilo CM, McGlashan TH, Morey LC, et al. : Internal
consistency, intercriterion overlap and diagnostic effi ciency
of criteria sets for DSM-IV schizotypal, borderline, avoid-
ant and obsessive-compulsive personality disorders. Acta
Psychiatr Scand 2001, 104: 264– 272.
21. Diaferia G, Bianchi I, Bianchi ML, et al. : Relationship
between obsessive-compulsive personality disorder and
obsessive-compulsive disorder. Compr Psychiatry 1997,
38: 38– 42.
22. Winsberg M, Cassic K, Koran L: Hoarding in obsessive-
compulsive disorder: a report of 20 cases. J Clin Psychiatry
1999, 60: 591– 597.
23. Hasler G, Pinto A, Greenberg BD, et al. : Familiality of fac-
tor analysis-derived YBOCS dimensions in OCD-affected
sibling pairs from the OCD Collaborative Genetics Study.
Biol Psychiatry 2007, 61: 617– 625.
24. Zhang H, Leckman JF, Pauls DL, et al. : Genomewide scan
of hoarding in sib pairs in which both sibs have Gilles de la
Tourette syndrome. Am J Hum Genet 2002, 70: 896– 904.
Recent Advances in Compulsive Hoarding Saxena 303
25.•• Samuels J, Shugart YY, Grados MA, et al. : Signifi cant linkage
to compulsive hoarding on chromosome 14 in families with
obsessive-compulsive disorder: results from the OCD Collab-
orative Genetics Study. Am J Psychiatry 2007, 164: 493– 499.
This genome-wide linkage study of 219 multiplex OCD families,
collected as part of the OCD Collaborative Genetics Study,
assessed genetic linkage with a phenotype defi ned by the presence
of clinically signifi cant compulsive hoarding symptoms in patients
with early-onset OCD (before age 18 years). It found “suggestive”
linkage of compulsive hoarding to a region on chromosome 14 and
signifi cant linkage to another region on chromosome 14 in families
with two or more hoarding relatives. This suggests that compulsive
hoarding may be a genetically discrete phenotype with an etiology
at least partially distinct from that of OCD in general.
26. Cohen L, Angladette L, Benoit N, Pierrot-Deseilligny C: A
man who borrowed cars. Lancet 1999, 353: 34.
27. Hahm DS, Kang Y, Cheong SS, Na DL: A compulsive col-
lecting behavior following an A-com aneurysmal rupture.
Neurology 2001, 56: 398– 400.
28. Volle E, Beato R, Levy R, Dubois B: Forced collectionism
after orbitofrontal damage. Neurology 2002, 58: 488– 490.
29. Nakaaki S, Murata Y, Sato J, et al. : Impairment of decision-mak-
ing cognition in a case of frontotemporal lobar degeneration
(FTLD) presenting with pathologic gambling and hoarding as the
initial symptoms. Cogn Behav Neurol 2007, 20: 121– 125.
30.• Anderson SW, Damasio H, Damasio AR: A neural basis for
collecting behaviour in humans. Brain 2005, 128: 201– 212.
This study compared 13 patients with compulsive hoarding
symptoms that began after they suffered brain damage with 54
brain-damaged patients who did not develop hoarding behaviors. All
hoarding patients had damage to the mesial prefrontal cortex. The
brain regions with greatest overlap in hoarders and least overlap with
nonhoarders were the right orbitofrontal pole, right rostral ACC,
and adjacent white matter. The authors suggested that damage to
these areas, which are involved in decision-making and planning,
disrupts the ability to inhibit urges to acquire and save items.
31.• Lawrence NS, Wooderson S, Mataix-Cols D, et al. : Deci-
sion making and set shifting impairments are associated
with distinct symptom dimensions in obsessive-compulsive
disorder. Neuropsychology 2006, 20: 409– 419.
This study was the fi rst to show specifi c neurocognitive defi cits
in compulsive hoarders. OCD patients with prominent hoarding
symptoms were found to have signifi cantly worse performance
on the Iowa Gambling Task than nonhoarding OCD patients and
controls, as well as lower skin conductance responses.
32. Saxena S, Brody A, Maidment KM, et al. : Cerebral glucose
metabolism in obsessive-compulsive hoarding. Am J
Psychiatry 2004, 161: 1038– 1048.
33. Saxena S, Bota RG, Brody AL: Brain-behavior relationships
in obsessive-compulsive disorder. Semin Clin Neuropsy-
chiatry 2001, 6: 82– 101.
34. Hartl TL, Frost RO, Allen GJ, et al. : Actual and perceived
memory defi cits in individuals with compulsive hoarding.
Depress Anxiety 2004, 20: 59– 69.
35. Mataix-Cols D, Wooderson S, Lawrence N, et al. : Distinct
neural correlates of washing, checking, and hoarding symp-
tom dimensions in obsessive-compulsive disorder. Arch Gen
Psychiatry 2004, 61: 564– 576.
36.• An SK, Mataix-Cols D, Lawrence NS, et al. : To discard or
not to discard: the neural basis of hoarding symptoms in
obsessive-compulsive disorder. Mol Psychiatry 2008 Jan 8
(Epub ahead of print).
This study used functional MRI to examine brain activation during
provocation of compulsive hoarding symptoms and found that hoarding
OCD patients had signifi cantly greater activation of the ventromedial
prefrontal cortex than nonhoarding OCD patients or normal controls.
Hoarding-related anxiety correlated with greater activation of the
ventromedial prefrontal cortex, mesial temporal lobe, sensorimotor
cortex, and thalamus but with less activation of the dorsal prefrontal,
parietal, and temporal cortical regions and basal ganglia. These results
elucidated the neural mediation of compulsive hoarding symptoms and
showed that it is quite different from that of “typical” OCD.
37.• Grisham JR, Brown TA, Savage CR, et al. : Neuropsycho-
logical impairment associated with compulsive hoarding.
Behav Res Ther 2007, 45: 1471– 1483.
This study found that compulsive hoarders had signifi cantly slower
and more variable reaction time, greater impulsivity, and worse
spatial attention than controls and a mixed clinical patient group.
These results indicate that compulsive hoarding is associated with
specifi c neurocognitive defi cits.
38. Black DW, Monahan P, Gable J, et al. : Hoarding and
treatment response in non-depressed subjects with obsessive-
compulsive disorder. J Clin Psychiatry 1998, 59: 420– 425.
39. Mataix-Cols D, Rauch SL, Manzo PA, et al. : Use of factor-ana-
lyzed symptom dimensions to predict outcome with serotonin
reuptake inhibitors and placebo in the treatment of obsessive-
compulsive disorder. Am J Psychiatry 1999, 156: 1409– 1416.
40. Stein DJ, Andersen EW, Overo KF: Response of symptom
dimensions in obsessive-compulsive disorder to treatment with
citalopram or placebo. Rev Bras Psiquiatr 2007, 29: 303– 307.
41. Alonso P, Menchon JM, Pifarre J, et al. : Long-term follow-up
and predictors of clinical outcome in obsessive-compulsive
patients treated with serotonin reuptake inhibitors and
behavioral therapy. J Clin Psychiatry 2001, 62: 535– 540.
42. Ferrao YA, Shavitt RG, Bedin NR, et al. : Clinical features
associated to refractory obsessive-compulsive disorder. J
Affect Disord 2006, 94: 199– 209.
43. Erzegovesi S, Cavallini MC, Cavedini P, et al. : Clinical pre-
dictors of drug response in obsessive-compulsive disorder. J
Clin Psychopharmacol 2001, 21: 488– 492.
44. Shetti CN, Reddy YC, Kandavel T, et al. : Clinical predic-
tors of drug nonresponse in obsessive-compulsive disorder.
J Clin Psychiatry 2005, 66: 1517– 1523.
45.•• Saxena S, Brody AL, Maidment KM, Baxter LR: Paroxetine
treatment of compulsive hoarding. J Psychiatr Res 2007,
41: 481– 487.
This was the fi rst prospective, quantitative study of pharmaco-
therapy for compulsive hoarding. Thirty-two compulsive hoarders
were found to respond equally well to paroxetine as 47 nonhoard-
ing OCD patients, with nearly identical improvements in OCD
symptoms, depression, anxiety, and overall functioning. Hoarding
symptoms responded as well as nonhoarding symptoms. These
results suggested that SRIs are just as effective for treatment of
compulsive hoarding as they are for nonhoarding OCD.
46. Mataix-Cols D, Marks IM, Greist JH, et al. : Obsessive-
compulsive symptom dimensions as predictors of compliance
with and response to behaviour therapy: results from a
controlled trial. Psychother Psychosom 2002, 71: 255– 262.
47. Abramowitz JS, Franklin ME, Schwartz SA, Furr JM:
Symptom presentation and outcome of cognitive-behavioral
therapy for obsessive-compulsive disorder. J Consult Clin
Psychol 2003, 71: 1049– 1057.
48. Rufer M, Fricke S, Moritz S, et al. : Symptom dimensions in
obsessive-compulsive disorder: prediction of cognitive-behavior
therapy outcome. Acta Psychiatr Scand 2006, 113: 440– 446.
49.• Tolin DF, Frost RO, Steketee G: An open trial of cognitive-
behavioral therapy for compulsive hoarding. Behav Res
Ther 2007, 45: 1461– 1470.
This study presented the methods and outcome of a CBT developed
specifi cally for compulsive hoarding. Ten of 14 patients completed
26 sessions of treatment, and fi ve improved greatly.