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Compulsive hoarders: How do they differ from individuals with obsessive compulsive disorder?
Psychiatry Research 200 (2012) 35–40
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Psychiatry Research journal homepage: www.elsevier.com/locate/psychres
Compulsive hoarders: How do they differ from individuals with obsessive compulsive disorder? Fugen Neziroglu a,b,n, Steven Weissman a, Jennifer Allen a, Dean McKay c a
Bio-Behavioral Institute, 935 Northern Boulevard Suite 102, Great Neck, NY 11021, USA Hofstra University, Hempstead, NY, USA c Fordham University, Bronx, NY, USA b
a r t i c l e i n f o
abstract
Article history: Received 21 October 2011 Received in revised form 27 March 2012 Accepted 1 April 2012
Hoarding has been considered a subtype of obsessive–compulsive disorder (OCD). Planned revisions to the diagnostic criteria propose that hoarding form a separate diagnosis in a larger category of obsessive compulsive related disorders. To date, there have been few direct comparisons between hoarding and those with other symptoms of OCD. This study builds on work that suggests compulsive hoarding, while similar to OCD, comprises a clinically distinct condition. Three groups were compared: those with OCD without compulsive hoarding symptoms (n ¼102), those with compulsive hoarding but not OCD (n¼ 21), and individuals who satisfied both criteria (n ¼ 25). The groups were compared on obsessionality, compulsivity, overvalued ideas, depression, and anxiety. The two hoarding groups were also compared on hoarding symptoms and savings cognitions. Results indicated that the hoarding-only group reported fewer symptoms than both OCD groups, including fewer obsessions and compulsions and lower depression. Both hoarding groups showed significantly higher overvalued ideas when compared to the OCD-only group. These results suggest that hoarders experience less subjective distress than those with OCD, yet have greater difficulty in challenging dysfunctional cognitions associated with the presenting condition. These findings suggest that individuals with hoarding, whether with or without OCD, will show greater difficulty engaging in cognitive-behavioral interventions. & 2012 Elsevier Ireland Ltd. All rights reserved.
Keywords: Hoarding Obsessive–compulsive disorder Overvalued ideas
1. Introduction Hoarding has recently gained considerable attention, notably for its serious occupational and functional disability, as well as for its public health impact (Frost and Hartl, 1996; Markarian et al., 2010). Conceptual work on the problem has focused on acquisition and difficulty in discarding possessions that, objectively, appear of limited value (Frost and Hartl, 1996).
1.1. Hoarding and obsessive–compulsive disorder Hoarding has been associated with obsessive–compulsive disorder (OCD), a finding that has been supported by factor analytic studies highlighting the prominence of hoarding behavior as a distinct symptom subtypes of OCD (e.g., Baer, 1994). Much of the factor analytic research that suggests hoarding is part of OCD comes from a single symptom checklist, and does not come from findings of shared pathophysiology or other central mechanisms of n
Corresponding author at: Bio-Behavioral Institute, 935 Northern Boulevard Suite 102, Great Neck, NY 11021, USA. Tel.: þ 1 516 487 7116; fax: þ 1 516 829 1731. E-mail address: [email protected] (F. Neziroglu). 0165-1781/$ - see front matter & 2012 Elsevier Ireland Ltd. All rights reserved. http://dx.doi.org/10.1016/j.psychres.2012.04.002
OCD (McKay et al., 2004). Compulsive hoarding is only described specifically in the Diagnostic and Statistical Manual-Fourth Edition-Text Revision (DSM-IV-TR) (APA, 2000) as a symptom of obsessive–compulsive personality disorder (OCPD), not OCD. Although the DSM-IV-TR does not explicitly mention compulsive hoarding as a symptom of OCD, hoarding-related obsessions and compulsions are purported to be quite common in patients with OCD (Hanna, 1995; Rasmussen and Eisen, 1992), with studies estimating the frequency of hoarding among individuals with OCD as ranging between 20% and 31% (Frost et al., 1996; Rasmussen and Eisen, 1992). However, the phenomenon of hoarding itself has been reported in patients diagnosed with a variety of different disorders, such as dementia (Hwang et al., 1998), psychotic disorders (Stein et al., 1997), eating disorders (Frankenburg, 1984), post-traumatic stress disorder (PTSD), and depression (Frost et al., 1996).
1.2. Distinctiveness of hoarding from obsessive–compulsive disorder More recently, many studies have begun to emphasize distinct differences between individuals diagnosed with OCD who hoard and those who do not (Abramowitz et al., 2008). For example, it has recently been found that individuals with OCD who were also compulsive hoarders were more likely than those with OCD who
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were not compulsive hoarders to have obsessions regarding symmetry and ordering, as well as more difficulty completing tasks and making decisions (Samuels et al., 2007). Individuals with hoarding show deficits in organizational memory (Jang et al., 2010) and poorer attention (Tolin et al., 2011). Individuals with OCD who hoard tend to have more first degree relatives who engage in excessive saving than those who do not hoard (Frost and Gross, 1993; Samuels et al., 2007). In addition, it was found that individuals with OCD who hoard have an earlier age of symptom onset (Fontenelle, et al., 2004; Samuels et al., 2007), suffer from greater levels of impairment (Lochner et al., 2005), have a lower quality of life (Fontenelle et al., 2010) and exhibit higher comorbidity rates with Axis I and II disorders, and tend to display less insight to the severity of their symptoms (Pertusa et al., 2008; Steketee and Frost, 2003). Individuals with OCD who hoard, when compared to those who do not, have also been found to respond less well to cognitive behavioral therapy as it applies to OCD (Abramowitz et al., 2003; Mataix-Cols et al., 2002). Instead, specifically tailored cognitive behavioral therapy, that does not necessarily resemble that used for other symptoms of OCD, has been found more effective for hoarding (Steketee et al., 2010). Hoarders may also exhibit a different pattern of neural activity. One study found that when compared to a non-OCD control group, individuals with OCD and hoarding behavior had significantly lower glucose metabolism in the posterior cingulate gyrus and cuneus, whereas those with non-hoarding OCD had higher glucose metabolism in the bilateral thalamus and caudate than normal controls. Those with hoarding also had significantly lower glucose metabolism in the dorsal anterior cingulate gyrus than individuals with OCD who did not hoard (Saxena et al., 2004). The authors suggested that these differences may help to explain previous findings that those who compulsively hoard respond less well than individuals with OCD without hoarding to psychopharmacological medication, specifically to serotonin reuptake inhibitors (Mataix-Cols et al., 1999). In a study comparing three groups—individuals diagnosed with OCD and hoarding, individuals with OCD without hoarding, and individuals displaying hoarding symptoms alone—Grisham et al. (2005) found that the pure hoarding group exhibited significantly lower levels of negative effect, depression, anxiety, and stress. Hoarding has also been found to have weaker correlations with common symptoms of OCD when compared to how those symptoms correlated with each other (Abramowitz et al., 2008; Wu and Watson, 2005). Abramowitz et al. (2008) also found that although individuals with OCD scored higher than individuals with other anxiety disorders and healthy controls on non-hoarding symptoms, there was no difference in scores for hoarding symptoms. Finally, Abramowitz et al. (2008) found the weakest factor loadings for measures of hoarding among a set of measures of obsessive–compulsive symptoms. All of these findings support the notion of conceptualizing hoarding behavior as a phenomenon distinct from OCD rather than one on a list of common OCD symptoms. In addition to these observed differences between hoarding and other symptoms of OCD, it has been noted that hoarding is generally less responsive to treatment (Pertusa et al., 2010). One variable examined in OCD that is related to a poorer prognosis is overvalued ideation (OVI). Overvalued ideation refers to an individual’s degree of the belief that their obsessions and associated compulsions represent reasonable thoughts and responses to the environment (Kozak and Foa, 1994; Neziroglu et al., 1999, 2004). This type of reasoning may be particularly common among individuals who hoard, as many believe strongly in the importance of acquiring and keeping their possessions as well as in the unacceptability of parting with them. This may explain why those who hoard can be particularly difficult to engage in treatment – often
arriving reluctantly due only to the persistence of their family members – as well as difficult to treat effectively once treatment is initiated (Neziroglu et al., 2004). Recent research has also begun to conceptualize differences between hoarding obsessions and hoarding compulsions (Rachman et al., 2009). Rachman et al. (2009) indicate that the experience of hoarding for the individual who hoards is nothing like the experience OCD patients have in their obsessions and compulsions. It is also noted that the compulsions of OCD individuals are stereotyped and specific day after day and the obsessions are recurrent, intrusive, unwanted and often repugnant. Thoughts of hoarders are not unwanted and intrusive and they do not engage in compulsions that are anxiety provoking. Rachman et al. (2009) state that the behaviors and emotional processes of compulsive hoarders are significantly different from those with OCD. The acquisition and protection of possessions is not distressing, but the clutter itself can be frustrating. It is the discarding of materials that is a major obstacle, and this has no resemblance to OCD compulsions (Rachman et al., 2009). A number of distinct lines of inquiry have all suggested that hoarding may be a distinct diagnostic entity (Pertusa et al., 2010). These include the aforementioned points, as well as basic biological processes. Lochner et al. (2005) identified a genotype more prevalent in those with OCD who experience hoarding symptoms than those with OCD without hoarding symptoms or other comparison groups. Saxena (2007) illustrated that not only does hoarding severity fail to correlate with the severity of other OCD symptoms, but neither do hoarders show more obsessive compulsive personality disorder traits than comparison samples (Steketee and Frost, 2003), and in fact, many hoarders do not demonstrate other OCD-related symptoms. Because the majority of research has examined the clinical characteristics of individuals with hoarding within the context of OCD (comparing OCD individuals with and without hoarding), the aim of the present investigation is to add to the small number of studies investigating hoarding as a distinct phenomenon. Based on the literature reviewed, we hypothesized that individuals with hoarding would show higher levels of overvalued ideation, but lower levels of obsessive–compulsive symptoms and other psychopathological signs and symptoms. However, given that it has been observed that some individuals who hoard also meet criteria for OCD, we examined three groups: (1) individuals diagnosed with OCD with no hoarding symptoms, (2) individuals who hoard but otherwise have no symptoms of OCD, and (3) individuals who hoard and meet criteria for OCD. It was expected that the group who met criteria for OCD who also had hoarding symptoms would show higher levels of OVI and lower levels of ancillary psychopathology symptoms when compared to those with OCD alone. It was hypothesized that given previous evidence cited above and consideration in DSM-V we hypothesize that hoarding may be a distinct phenomena in its own that is unrelated to OCD.
2. Method 2.1. Participants and procedure The participants were 148 patients who sought treatment for either obsessive–compulsive or hoarding symptoms at the Bio-Behavioral Institute (BBI), a well-recognized facility for the treatment of anxiety and mood disorders in Great Neck, New York. All participants completed informed consent prior to evaluation for the study. There were 102 participants who were diagnosed with OCD without significant hoarding symptoms (OCD-only group), 21 who were diagnosed with hoarding but without meeting criteria for a diagnosis of OCD (hoarding-only group), and 25 who were diagnosed with OCD as well as a clinically significant hoarding problem (combined group). The sample was recruited over the course of several years following diagnosis by a licensed psychologist trained in assessment and treatment of both OCD and hoarding.
F. Neziroglu et al. / Psychiatry Research 200 (2012) 35–40 Completion of the study instruments was part of the routine evaluation process at BBI. All participants provided informed consent for their questionnaires to be used for research purposes. DSM-IV-TR (APA, 2000) criteria were used to diagnose patients with OCD. In addition, The Padua Inventory (Sanavio, 1988) and Yale–Brown Obsessive– Compulsive Scale Symptom Checklist (Y–BOCS SC; Goodman et al., 1989a,b) were used to support diagnoses of the OCD-only group. The severity of OCD for this group was determined by the Yale–Brown Obsessive–Compulsive Scale (Y–BOCS; Goodman, et al., 1989a,b). In order to establish a clinical hoarding problem irrespective of any other obsessive–compulsive symptoms, Frost and Hartl’s (1996) diagnostic criteria for hoarding was applied as follows: (1) the individual acquires and fails to discard large numbers of possessions which appear to be useless or of limited value; (2) the individual’s living space is sufficiently cluttered as to preclude normal use and activities; (3) the individual experiences significant distress or impairment in functioning. In addition, pictures taken of the home, as well as home visits were used to substantiate the Frost and Hartl (1996) criteria. Only pictures of the homes of hoarders were used to provide evidence of hoarding and to validate the diagnosis. Family members also indicated that hoarding was the principle reason for seeking treatment at the Bio-Behavioral Institute. Data collected from the Savings Inventory-Revised (SI-R; Frost et al., 2004) was used to support diagnoses. Finally, the OCD with hoarding group was diagnosed using all of the aforementioned criteria, both for OCD and for Hoarding. The OCD-only group was comprised of 54 males and 48 females, with a mean age of 31.7 years (S.D. ¼14.0). The hoarding-only group was comprised of seven males and 14 females, with a mean age of 53.7 years (S.D. ¼ 15.8). The third group, those with both OCD and hoarding, consisted of nine males and 16 females, with a mean age of 49.2 years (S.D. ¼ 13.0). There was a significant group effect for age, F (2, 145)¼ 30.86, p o 0.001, with the OCD-only participants being significantly younger, on average, than those in both hoarding groups. This is consistent with previous findings that individuals seeking treatment for hoarding tend to be older than their non-hoarding counterparts presenting with OCD (Steketee and Frost, 2006).
2.2. Materials 2.2.1. Yale–Brown Obsessive–Compulsive Scale The Yale–Brown Obsessive–Compulsive Scale (Y–BOCS; Goodman et al., 1989a,b) is a semi-structured interview that assesses obsessions and compulsions, as well as generates a total score. There are five identical items for each subscale, assessing frequency, distress, social/occupational interference, resistance, and control over either obsessions or compulsions. Each item is rated from zero to four, with higher scores indicative of greater symptomatology. Factor analytic findings have confirmed the validity of the two distinct subscales (i.e., obsessions and compulsions) and therefore the present results are presented below for both scales (Amir et al., 1997; McKay et al., 1995, 1998). The psychometric properties of the measure have been well established (Taylor et al., 2010).
2.2.2. The Padua Inventory The Padua Inventory (Sanavio, 1988) consists of 60 items describing common obsessive and compulsive behaviors and was developed for administration to clinical and non-clinical samples. Internal consistency and one-month reliability has been found to be satisfactory. Concerning validity, the Padua Inventory has been shown to correlate significantly with other measures of OCD such as the Maudsley Obsessional–Compulsive Questionnaire (r¼ 0.70) and the Leyton Obsessional–Compulsive Inventory (r¼ 0.71 with Symptom scales; r¼ 0.66 with Trait scales). Four factors have been identified: impaired control of mental activities, becoming contaminated, checking behaviors, and urges and worries of losing control over motor behaviors.
2.2.3. Overvalued Ideas Scale The Overvalued Ideas Scale (OVIS; Neziroglu et al., 1999) is an 11-item clinician administered scale that assesses the extent to which a patient holds his or her obsessional belief to be true. Subjective characteristics of the belief, including strength, reasonableness, fluctuation over time, accuracy, agreement of others, effectiveness of compulsions, insight, and strength of resistance are assessed on separate 10-point Likert scales. The average of the first 10 items provides an estimate of one’s degree of overvalued ideas, with higher scores representing greater levels of OVI. The final item is an indication of the duration of the main belief. Reliability and validity data have indicated an internal consistency of a ¼ 0.95 and a test–re-test reliability, over a period of four weeks, of r ¼0.93. The obsessional beliefs indentified by individuals with compulsive hoarding were generally similar to those noted on the Savings Cognitions Scale (Frost et al., 2004). Some examples from the participant sample include, ‘‘throwing out the newspapers may mean getting rid of information I need in the future,’’ and ‘‘I love the belongings of my late husband and I could not tolerate discarding them; it would be like throwing away all of my memories.’’
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2.2.4. Beck Depression Inventory-II The Beck Depression Inventory-II (BDI-II; Beck et al., 1996a,b is a 21-item measure of the intensity of signs and symptoms typically associated with depression. Each item is rated from zero (neutral) to three (severe symptomatology). Numerous studies have supported the good psychometric status of the BDIII. Internal consistency has shown to be high (a ¼ 0.91) and test re-test reliability also (a ¼ 0.93). 2.2.5. Beck Anxiety Inventory The Beck Anxiety Inventory (BAI; Beck et al., 1988) is a 21-item measure of the severity of anxious symptoms (Beck and Steer, 1993). Items are rated in a similar fashion to the BDI-II, and assess symptoms and cognitions associated with anxiety. The reliability and validity of the BAI are well established for both clinical and non-clinical samples (Beck and Steer, 1993). It has shown high internal consistency (a ¼0.92), and test–re-test reliability over one week of r(81)¼ 0.75 (Beck et al., 1988). 2.2.6. Saving Cognitions Inventory-Revised The Saving Cognitions Inventory-Revised (SCI-R; Frost et al., 2004) is a 24-item scale measuring cognitions related to hoarding behaviors. It has four subscales: memory for possessions, control over possessions, responsibility for possessions, and emotional attachment to possessions. Alpha coefficients ranged from good to excellent (0.86–0.95) for each of the subscales, and was 0.96 for the item total score. Inter-item correlations were also acceptable and ranged from 0.40 to 0.87 (Frost et al., 2004). 2.2.7. Saving Inventory-Revised The Saving Inventory-Revised (SI-R; Frost et al., 2004) is a 23-item scale measuring hoarding behaviors. There are three factors in this scale: clutter, difficulty discarding, and acquisition. Test–re-test reliability was high, r¼ 0.86 for the total score, 0.89 for difficulty discarding, 0.90 for clutter, and 0.78 for acquisition (Frost et al., 2004).
3. Results A series of one-way analyses of covariance (ANCOVAs), with age and sex as covariates, were run comparing the three groups of participants on the Y–BOCS, Padua Inventory, BDI-II, BAI, and OVIS, as well as the two subscales of the Y–BOCS, yielding a total of seven comparisons. An additional two ANCOVAs were run comparing just the two hoarding groups on the SCI-R and SI-R. See Table 1 for means and S.D.s for each measure, broken down by group, as well as the results of the group difference tests. The False Discovery Rate (FDR; Benjamini and Hochberg, 1995) was used to correct for Type I error. All the outcome measures and comparisons yielded statistical significance. The ANCOVAs comparing the two hoarding groups on the SI-R and SCI-R were not included in this correction method because they represented a different set of group comparisons. 3.1. Obsessive–compulsive symptoms A significant group effect was found for the Y–BOCS total score, F(2, 143) ¼17.68, p o0.001, Z2 ¼ 0.23, the Y–BOCS Obsessions subscale, F(2, 143)¼23.46, po.0001, Z2 ¼0.28, the Y–BOCS compulsions subscale, F(2, 143) ¼9.47, p o0.001, Z2 ¼0.14, and the Padua Inventory, F(2, 143)¼ 5.27, po0.01, Z2 ¼0.08. Pairwise comparison follow-up analyses, using the FDR correction, revealed that in all cases, the hoarding-only group scored significantly lower on these measures of general OCD symptomatology than both the OCD-only group and the combined group. On the Y–BOCS-obsessions scale only, the combined group also scored lower than the OCD-only group (p o0.05). However, even in this case, the difference between the hoarding-only group and each of the other two groups was clearly the more robust finding. 3.2. Affective measures On the BDI-II, there was a significant group effect on depressive symptomatology, F(2, 143)¼6.31, po0.01, Z2 ¼ 0.09. Follow-up
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Table 1 Means by group on study measures with tests for group differences. Measure
Y–BOCS: total score Y–BOCS: obs. Y–BOCS: comp. Padua inventory BAI BDI OVIS SCI-R SI-R
Mean (S.D.) OCD group
Hoarding group
Combined group
24.34 (7.27) 12.81 (3.54) 11.56 (4.36) 36.90 (24.25) 18.58 (12.03) 20.38 (12.13) 4.77 (1.70)
9.23 3.77 5.46 11.21 8.67 11.29 6.28 79.12 58.24
21.29 10.05 11.00 37.90 15.96 23.30 6.22 82.46 54.53
(6.60) (3.77) (3.69) (11.71) (9.11) (7.14) (1.65) (26.73) (15.82)
(9.13) (5.03) (4.88) (23.45) (11.54) (13.91) (1.45) (35.46) (21.82)
F
Z2
17.68nnn 23.46nnn 9.47nnn 5.27nn 4.34n 6.31nn 9.29nnn 0.23 0.02
0.23 0.28 0.14 0.08 0.06 0.09 0.17 0.01 0.00
Note: Y–BOCS¼ Yale–Brown Obsessive–Compulsive Scale; Obs. ¼ Obsessions Scale; Com. ¼ Compulsions Scale; OVIS¼ Overvalued Ideas Scale; BDI¼ Beck Depression Inventory-II; BAI¼ Beck Anxiety Inventory, SCI-R ¼Saving Cognitions Inventory-Revised; SI-R ¼Saving Inventory-Revised. y p o 0.10. p o0.05. po 0.01. nnn p o 0.001. n
nn
analyses again revealed significant differences, with the hoardingonly group again scoring lower than both of the OCD groups and no significant difference found between the latter two groups. The same trend was evident when comparing the groups on symptoms of anxiety, as there was also a significant group effect on the BAI, F(2, 143)¼4.34, po0.05, Z2 ¼ 0.06. Pairwise comparisons indicated that the hoarding-only group reported significantly less anxiety than both of the other groups. No significant differences were observed between the OCD only and OCD with hoarding groups. 3.3. Overvalued ideas There was a significant group effect on the OVIS, F(2, 143) ¼ 9.29, po0.001, Z2 ¼0.17. Unlike the follow-up analyses reported above in which the hoarding-only group was consistently found to be the one generally driving the group effect, on this measure of overvalued ideas, the OCD-only group scored significantly lower than both the hoarding-only group and the combined group. There was no statistical difference between the latter two groups. 3.4. Hoarding symptomatology The hoarding-only and OCD with hoarding groups were also compared on the SI-R and SCI-R. No significant group differences were found for either measure. As a follow-up to ensure that no specific differences were missed, additional ANCOVAs (with age and sex as covariates) were conducted on the four subscales of the SCI-R and the three subscales of the SI-R. No significant group differences were found. The SI-R and SCI-R, which assess behaviors and cognitions associated with hoarding, could be viewed as simply a proxy for overvalued ideation. In order to determine whether there are distinctions between the aspects of psychopathology assessed with the OVI, ANCOVA was conducted whereby the OVI was compared between the hoarding-only and OCD with hoarding groups, while controlling for SI-R and SCI-R. These analyses revealed that the OVI accounts for unique variance when controlling for the SI-R (F(1, 44)¼7.92, p o0.01) and when controlling for the SCI-R (F(1, 44) ¼10.27, po0.001). 4. Discussion The present study was an investigation of the extent to which individuals with compulsive hoarding differ from those with
obsessive–compulsive disorder (OCD). Hoarding behavior has been considered a part of OCD as a subtype based on factor and cluster analytic research (McKay et al., 2004). However, more recent conceptualizations of hoarding have suggested that specific mechanisms distinguish it from OCD, with recommendations that it form a separate diagnosis (Pertusa et al., 2010). The present investigation adds to the growing literature that shows significant phenomenological differences between hoarding and OCD by comparing three groups: OCD-only, hoarding-only, and combined hoarding and OCD. Consistent with previous findings (e.g., Steketee and Frost, 2006), hoarders were found to be older, on average, than those diagnosed with OCD only. This may be a function of both the time it takes for accumulation of material items to reach levels that create impairment, as well as the tendency of those who hoard to avoid treatment (Neziroglu et al., 2004). Results indicated that the participants with hoarding only endorsed significantly fewer obsessive and compulsive symptoms than both the OCD-only group and the combined group. In other words, the presence of diagnosis of OCD predicted much higher scores on obsessive–compulsive symptomatology, irrespective of hoarding behavior. Furthermore, if hoarding did represent a subtype of OCD, one might expect those in the combined OCD and hoarding group to score higher than the OCD-only group due to the presence of additional OCD symptoms. This was not the case for any of these measurements. The strength of our threegroup approach is evident in these results; previous investigations that have suggested that individuals with hoarding do not differ from those with OCD (e.g., Frost et al., 2000) generally compared hoarders to non-hoarders, but with both groups meeting criteria for OCD. Pure hoarders scored quite low on two common measures of OCD symptoms, and the presence of clinical hoarding behavior did not predict a higher level of overall OCD symptomatology in those with the OCD diagnosis. These results support the notion that hoarding is better conceptualized as distinct from the diagnosis of OCD. Next, the three groups were compared on general levels of depressive and anxious symptoms as measured by the BDI-II and the BAI, respectively. On both measures, the hoarding-only group again scored significantly lower than both the OCD-only group and the combined group, whereas the latter two groups were roughly equivalent, suggesting much less affective disturbance for those with hoarding only. This is consistent with Grisham and Barlow (2005) finding that those who hoard without other OCD symptoms reported significantly less anxiety, worry, stress, and negative affect when compared to those with OCD. With respect
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to depression, our findings are not consistent with other literature showing that individuals with hoarding have higher levels of depression (discussed in Pertusa et al., 2010). Overvalued ideation, an important concept traditionally applied to those with obsessive–compulsive behavior (i.e., Kozak and Foa, 1994), was also examined. This is a measure of the strength of conviction in one’s beliefs, such as, ‘‘it is important to keep these papers just in case I need them in the future, if I do not have my husband’s belongings I will not remember all the good time we sharedy’’ Whereas the hoarding-only group stood out from the remaining two groups in all of the comparisons described thus far, when compared on the Overvalued Ideation Scale (OVIS), it was the OCD-only group that exhibited significantly fewer overvalued ideas than both the hoarding-only group and the combined group. Although the content of the belief may be different between the OCD-only and Hoarding-only group, it is not the content of the belief that is important but rather how strongly one believes in the thought. It is the strength of the conviction in a belief, regardless of content, that is important to determine how easy or difficult it may be to change the belief. Additional analyses where assessments of hoarding (the SI-R and SCI-R) were controlled showed that the OVI contributed uniquely to the difference between the OCD with hoarding compared to the hoarding only groups. Across all groups, it was the participants with hoarding (with or without OCD) who scored higher on this measure. This finding is consistent with reports of individuals who enter treatment for hoarding being more resistant to treatment. Although these individuals may present with many fewer symptoms of anxiety, and obsessionality, as well as fewer compulsive behaviors, their strong belief in the appropriateness of their appraisals of their possessions may lead to greater difficultly with challenging these thoughts and giving up their accumulated possessions. This finding is limited to the hoarding only and OCD with hoarding groups. The SI-R and SCI-R were examined to determine hoarding symptomology between the two hoarding groups. Because there was no difference between the hoarding only and OCD with hoarding groups on this measures this indicates that the diagnosis of hoarding was appropriate and that any differences between these two groups was driven by the OCD symptoms, e.g., more anxiety, depression when OCD is present. The present investigation builds on previous studies emphasizing the phenomenological differences between those individuals with hoarding and those with OCD. By self-report, the hoarding population is less anxious, less depressed, experiences lower obsessional ideation, and engages in fewer compulsive behaviors. Moreover, those who hoard generally believe quite strongly in the rationale for accumulating and saving. It may be that a primary factor in the tendency of these individuals to avoid treatment is that they do not perceive it to be a significant problem. However, case studies suggest that hoarding can be extremely deleterious to an individual in terms of the monetary cost (e.g., additional storage space, replacing inaccessible items, and repairs associated with deteriorating housing, accumulation of possessions), physical risk (e.g., treacherous living conditions, fire hazards, and blocked exits), interpersonal relationship conflicts (e.g., inability to entertain guests and significant anger from cohabitating family members), and even legal problems should government agencies become aware of the living conditions. Nevertheless, many who suffer in these circumstances only seek treatment under strong pressure from family members (Neziroglu et al., 2004). This stark contrast between perception and reality further underscores the notion of conceptualizing and treating compulsive hoarding as a distinct disorder. There are several limitations worth noting. First, there was no accounting for other comorbid conditions. While the findings
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consistently showed that individuals with hoarding had higher levels of OVI, and lower levels of OCD symptoms as well as ancillary psychopathology, the presence of comorbid conditions or signs may have impacted the results. Further, while it was implied that individuals with hoarding only and those with OCD accompanied by hoarding showed higher levels of OVI it is unclear whether there is a distinction in treatment outcome between these two groups. In addition, while the diagnoses were not conducted using available structured interviews, the diagnoses were rendered using the available criteria for hoarding as available in the literature and further verified using case conference. Future research should rely on recently developed structured interviews for establishing the presence of hoarding disorder (Tolin et al., 2010). In addition, the sample was relatively small and future research is warranted with larger groups to ensure that variability is adequately accounted for and differences between the groups may be more validly attributed to distinct features of hoarding pathology. Finally, the present sample included only individuals with hoarding who sought treatment, and was relatively small in size. Future research is warranted to determine whether the presence of hoarding in conjunction with OCD presents a barrier to treatment, among individuals actively seeking treatment as well as those who are referred for treatment under duress, such as by family pressure or due to court mandate (such as in animal hoarding, where there are higher level of legal consequences; Frost et al., 2011). In conclusion, the findings from this study contribute to the growing body of research that shows hoarding to be distinct from OCD.
Acknowledgments The authors would like to thank Jonathan Reinharth and Jennifer Wilson for their assistance in data collection and entry.
References Abramowitz, J.S., Franklin, M.E., Schwartz, S.A., Furr, J.M., 2003. Symptom presentation and outcome of cognitive-behavioral therapy for obsessive– compulsive disorder. Journal of Counseling and Clinical Psychology 71, 1049–1057. Abramowitz, J.S., Wheaton, M.G., Storch, E.A., 2008. The status of hoarding as asymptom of obsessive–compulsive disorder. Behaviour Research and Therapy 46, 1026–1033. American Psychiatric Association, 2000. Diagnostic and Statistical Manual of Mental Disorders, fourth ed., Text Revision. Author, Washington, DC. Amir, N., Foa, E.B., Coles, M., 1997. Factor structure of the Yale–Brown obsessive– compulsive scale. Psychological Assessment 9, 312–316. Baer, L., 1994. Factor analysis of symptom subtypes of obsessive compulsive disorder and their relation to personality and tic disorders. Journal of Clinical Psychiatry 55, 18–23. Beck, A.T., Epstein, N., Brown, G., Steer, R.A., 1988. An inventory for measuring clinical anxiety: psychometric properties. Journal of Consulting and Clinical Psychology 56, 893–897. Beck, A.T., Steer, R.A., 1993. Beck anxiety inventory. Harcourt, Brace and Co, San Antonia. Beck, A.T., Steer, R.A., Brown, G.K., 1996a. Manual for the Beck depression inventory-II. Psychological Corporation, San Antonio, TX. Beck, A.T., Steer, R.A., Ball, R., Ranieri, W., 1996b. Comparison of Beck depression inventories – IA and – II in psychiatric outpatients. Journal of Personality Assessment 67, 588–597. Benjamini, Y., Hochberg, Y., 1995. Controlling the false discovery rate: a practical and powerful approach to multiple testing. Journal of the Royal Statistical Society, Series B 57, 289–300. Fontenelle, I.S., Fontenelle, L.F., Borges, M.C., Prazeres, A.M., Range, B.P., Mendelowicz, M.V., Versiani, M., 2010. Quality of life and symptom dimensions of patients with obsessive–compulsive disorder. Psychiatry Research 179, 198–203. Fontenelle, L.F., Mendlowicy, M.V., Soarez, I.D., Versiani, M., 2004. Patients with obsessive–compulsive disorder and hoarding symptoms: a distinctive clinical subtype? Comprehensive Psychiatry 45, 375–383. Frankenburg, F., 1984. Hoarding in anorexia nervosa. British Journal of Medical Psychology 57, 57–60.
40
F. Neziroglu et al. / Psychiatry Research 200 (2012) 35–40
Frost, R.O., Gross, R.C., 1993. The hoarding of possessions. Behaviour Research and Therapy 31, 367–381. Frost, R.O., Hartl, T.L., 1996. A cognitive-behavioral model of compulsive hoarding. Behaviour Research and Therapy 34, 341–350. Frost, R.O., Krause, M., Steketee, G., 1996. Hoarding and obsessive compulsive symptoms. Behaviour Modification 20, 116–132. Frost, R.O., Patronek, G., Rosenfield, E., 2011. Comparison of object and animal hoarding. Depression and Anxiety 28, 885–891. Frost, R.O., Steketee, G., Grisham, J., 2004. Measurement of compulsive hoarding: saving inventory revised. Behaviour Research and Therapy 42, 1163–1182. Frost, R.O., Steketee, G., Williams, L.F., Warren, R., 2000. Mood, personality disorder symptoms, and disability in obsessive compulsive hoarders: a comparison with clinical and non-clinical controls. Behaviour Research and Therapy 38, 1071–1081. Goodman, W.K., Price, L.H., Rasmussen, S.A., Mazure, C., Fleischmann, R.L., Hill, C.L., Hening, G.R., Charney, D.S., 1989a. The Yale–Brown Obsessive Compulsive scale, I: development, use, and reliability. Archives of General Psychiatry 46, 1006–1011. Goodman, W.K., Price, L.H., Rasmussen, S.A., Mazure, C., Delgado, P., Heninger, G.R., Dennis, S., Charney, D.S., 1989b. The Yale–Brown obsessive compulsive scale, II: validity. Archives of General Psychiatry 46, 1012–1016. Grisham, J.R., Barlow, D.H., 2005. Compulsive hoarding: current research and theory. Journal of Psychopathology and Behavioral Assessment 27, 45–52. Grisham, J.R., Brown, T.A., Liverant, G.I., Campbell-Sills, L., 2005. The distinctiveness of compulsive hoarding from obsessive–compulsive disorder. Journal of Anxiety Disorders 19, 767–779. Hanna, G.L., 1995. Demographic and clinical features of obsessive–compulsive disorder in children and adolescents. Journal of American Academy of Child and Adolescent Psychiatry 34, 19–27. Hwang, J.P., Tsai, S.J., Yang, C.H., Liu, K.M., Lirng, J.F., 1998. Hoarding behavior in dementia. A preliminary report. American Journal of Geriatric Psychiatry 6, 285–289. Jang, J.H., Kim, H.S., Ha, T.H., Shin, N.Y., Kang, D.H., Choi, J.S., Ha, K., Kwon, J.S., 2010. Nonverbal memory and organization dysfunctions are related with distinct symptom dimensions in obsessive–compulsive disorder. Psychiatry Research 180, 93–98. Kozak, M.J., Foa, E.B., 1994. Obsessions, overvalued ideas, and delusions in obsessive–compulsive disorder. Behaviour Research and Therapy 32, 343–353. Lochner, C., Kinnear, C.J., Hemmings, S.M.J., Seller, C., Niehaus, D.J.H., Knowles, J.A., et al., 2005. Hoarding in obsessive–compulsive disorder: clinical and genetic correlates. Journal of Clinical Psychiatry 66, 1155–1160. Markarian, Y., Larson, M.J., Aldea, M.A., Baldwin, S.A., Good, D., Berkeljon, A., Murphy, T.K., Storch, E.A., McKay, D., 2010. Multiple pathways to functional impairment in obsessive–compulsive disorder. Clinical Psychology Review 30, 78–88. Mataix-Cols, D., Marks, I.M., Griest, J.H., Kobak, K.A., Baer, L., 2002. Obsessive– compulsive symptom dimensions as predictros of compliance with and response to behaviour therapy: results from a controlled trial. Psychotherapy and Psychosomatics 71, 255–262. Mataix-Cols, D., Rauch, S.L., Manzo, P.A., Jenike, M.A., Baer, L., 1999. Use of factoranalyzed symptom dimensions to predict outcome with serotonin reuptake inhibitors and placebo in the treatment of obsessive–compulsive disorder. American Journal of Psychiatry 156, 1409–1416. McKay, D., Abramowitz, J., Calamari, J., Kyrios, M., Radomsky, A., Sookman, D., Taylor, S., Wilhelm, S., 2004. A critical evaluation of obsessive–compulsive disorder subtypes: symptoms versus mechanisms. Clinical Psychology Review 24, 283–313.
McKay, D., Danyko, S., Neziroglu, F., Yaryura-Tobias, J.A., 1995. Factor structure of the Yale–Brown obsessive–compulsive scale: a two dimensional measure. Behaviour Research and Therapy 33, 865–869. McKay, D., Neziroglu, F., Stevens, K., Yaryura-Tobias, J.A., 1998. The Yale–Brown obsessive–compulsive scale: confirmatory factor analytic findings. Journal of Psychopathology and Behavioral Assessment 20, 265–274. Neziroglu, F., Bubrick, J., Yaryura-Tobias, J.A., 2004. Overcoming compulsive hoarding. New Harbinger Press, California. Neziroglu, F., Pinto, A., Yaryura-Tobias, J.A., McKay, D., 2004. Overvalued ideation as a predictor of fluvoxamine response in patients with obsessive–compulsive disorder. Psychiatry Research 125, 53–60. Neziroglu, F., Stevens, K., McKay, D., Todaro, J., Yaryura-Tobias, J.A., 1999. Development of the overvalued ideas scale: reliability and validity. Behaviour Research and Therapy 37, 881–902. Pertusa, A., Frost, R.O., Fullana, M.A., Samuels, J., Steketee, G., Tolin, D.F., Saxena, S., Leckman, J.F., Mataix-Cols, D., 2010. Refining the diagnostic boundaries of compulsive hoarding: a critical review. Clinical Psychology Review 30, 371–386. Pertusa, A., Fullana, M.A., Singh, S., Alonso, P., Menchon, J.M., Mataix-Cols, D., 2008. Compulsive hoarding: OCD symptom, distinct clinical syndrome, or both? American Journal of Psychiatry 165, 1289–1298. Rachman, S., Elliott, C.M., Shafran, R., Radomsky, A.S., 2009. Separating hoarding from OCD. Behaviour Research and Therapy 47, 520–522. Rasmussen, S., Eisen, J., 1992. The epidemiology and clinical features of obsessive compulsive disorder. The Psychiatric Clinics of North America 15, 743–758. Samuels, J.F., Bienvenu, O.J., Pinto, A., Fyer, A.J., McCracken, J.T., Rauch, S.L., et al., 2007. Hoarding in obsessive–compulsive disorder: results from the OCD collaborative genetics study. Behaviour Research and Therapy 45, 673–686. Sanavio, E., 1988. Obsessions and compulsions: the Padua inventory. Behaviour Research and Therapy 26, 169–177. Saxena, S., 2007. Is compulsive hoarding a genetically and neurobiologically discretesyndrome? Implications for diagnostic classification. American Journal of Psychiatry 164, 380–384. Saxena, S., Brody, A.L., Maidment, K.M., Smith, E.C., Zohrabi, N., Katz, E., et al., 2004. Cerebral glucose metabolism in obsessive–compulsive hoarding. American Journal of Psychiatry 161, 1038–1048. Stein, D.J., Lasylo, B., Marasi, E., Seedat, S., Potocnik, F., 1997. Hoarding symptoms in patients on a geriatric psychiatry inpatient unit. South African Medical Journal 87, 1138–1140. Steketee, G., Frost, R.O., 2003. Compulsive hoarding: current status of the research. Clinical Psychological Review 23, 905–927. Steketee, G., Frost, R.O., 2006. Compulsive hoarding and acquiring: therapist guide (treatments that work). Oxford University Press, New York. Steketee, G., Frost, R.O., Tolin, D.F., Rasmussen, J., Brown, T.A., 2010. Waitlist controlled trial of cognitive behavior therapy for hoarding disorder. Depression and Anxiety 27, 476–484. Taylor, S., Abramowitz, J.S., McKay, D., 2010. Obsessive–compulsive disorder. In: Antony, M.M., Barlow, D.H. (Eds.), Handbook of Assessment and Treatment Planning for Psychological Disorders, second ed. The Guilford Press, New York, pp. 267–300. Tolin, D.F., Frost, R.O., Steketee, G., 2010. A brief interview for assessing compulsive hoarding: the hoarding rating scale-interview. Psychiatry Research 178, 147–152. Tolin, D.F., Villavicencio, A., Umbach, A., Kurtz, M.M., 2011. Neuropsychological functioning in hoarding disorder. Psychiatry Research 189, 413–418. Wu, K., Watson, D., 2005. Hoarding and its relation to obsessive–compulsive disorder. Behaviour Research and Therapy 43, 897–921.
Contents lists available at SciVerse ScienceDirect
Psychiatry Research journal homepage: www.elsevier.com/locate/psychres
Compulsive hoarders: How do they differ from individuals with obsessive compulsive disorder? Fugen Neziroglu a,b,n, Steven Weissman a, Jennifer Allen a, Dean McKay c a
Bio-Behavioral Institute, 935 Northern Boulevard Suite 102, Great Neck, NY 11021, USA Hofstra University, Hempstead, NY, USA c Fordham University, Bronx, NY, USA b
a r t i c l e i n f o
abstract
Article history: Received 21 October 2011 Received in revised form 27 March 2012 Accepted 1 April 2012
Hoarding has been considered a subtype of obsessive–compulsive disorder (OCD). Planned revisions to the diagnostic criteria propose that hoarding form a separate diagnosis in a larger category of obsessive compulsive related disorders. To date, there have been few direct comparisons between hoarding and those with other symptoms of OCD. This study builds on work that suggests compulsive hoarding, while similar to OCD, comprises a clinically distinct condition. Three groups were compared: those with OCD without compulsive hoarding symptoms (n ¼102), those with compulsive hoarding but not OCD (n¼ 21), and individuals who satisfied both criteria (n ¼ 25). The groups were compared on obsessionality, compulsivity, overvalued ideas, depression, and anxiety. The two hoarding groups were also compared on hoarding symptoms and savings cognitions. Results indicated that the hoarding-only group reported fewer symptoms than both OCD groups, including fewer obsessions and compulsions and lower depression. Both hoarding groups showed significantly higher overvalued ideas when compared to the OCD-only group. These results suggest that hoarders experience less subjective distress than those with OCD, yet have greater difficulty in challenging dysfunctional cognitions associated with the presenting condition. These findings suggest that individuals with hoarding, whether with or without OCD, will show greater difficulty engaging in cognitive-behavioral interventions. & 2012 Elsevier Ireland Ltd. All rights reserved.
Keywords: Hoarding Obsessive–compulsive disorder Overvalued ideas
1. Introduction Hoarding has recently gained considerable attention, notably for its serious occupational and functional disability, as well as for its public health impact (Frost and Hartl, 1996; Markarian et al., 2010). Conceptual work on the problem has focused on acquisition and difficulty in discarding possessions that, objectively, appear of limited value (Frost and Hartl, 1996).
1.1. Hoarding and obsessive–compulsive disorder Hoarding has been associated with obsessive–compulsive disorder (OCD), a finding that has been supported by factor analytic studies highlighting the prominence of hoarding behavior as a distinct symptom subtypes of OCD (e.g., Baer, 1994). Much of the factor analytic research that suggests hoarding is part of OCD comes from a single symptom checklist, and does not come from findings of shared pathophysiology or other central mechanisms of n
Corresponding author at: Bio-Behavioral Institute, 935 Northern Boulevard Suite 102, Great Neck, NY 11021, USA. Tel.: þ 1 516 487 7116; fax: þ 1 516 829 1731. E-mail address: [email protected] (F. Neziroglu). 0165-1781/$ - see front matter & 2012 Elsevier Ireland Ltd. All rights reserved. http://dx.doi.org/10.1016/j.psychres.2012.04.002
OCD (McKay et al., 2004). Compulsive hoarding is only described specifically in the Diagnostic and Statistical Manual-Fourth Edition-Text Revision (DSM-IV-TR) (APA, 2000) as a symptom of obsessive–compulsive personality disorder (OCPD), not OCD. Although the DSM-IV-TR does not explicitly mention compulsive hoarding as a symptom of OCD, hoarding-related obsessions and compulsions are purported to be quite common in patients with OCD (Hanna, 1995; Rasmussen and Eisen, 1992), with studies estimating the frequency of hoarding among individuals with OCD as ranging between 20% and 31% (Frost et al., 1996; Rasmussen and Eisen, 1992). However, the phenomenon of hoarding itself has been reported in patients diagnosed with a variety of different disorders, such as dementia (Hwang et al., 1998), psychotic disorders (Stein et al., 1997), eating disorders (Frankenburg, 1984), post-traumatic stress disorder (PTSD), and depression (Frost et al., 1996).
1.2. Distinctiveness of hoarding from obsessive–compulsive disorder More recently, many studies have begun to emphasize distinct differences between individuals diagnosed with OCD who hoard and those who do not (Abramowitz et al., 2008). For example, it has recently been found that individuals with OCD who were also compulsive hoarders were more likely than those with OCD who
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were not compulsive hoarders to have obsessions regarding symmetry and ordering, as well as more difficulty completing tasks and making decisions (Samuels et al., 2007). Individuals with hoarding show deficits in organizational memory (Jang et al., 2010) and poorer attention (Tolin et al., 2011). Individuals with OCD who hoard tend to have more first degree relatives who engage in excessive saving than those who do not hoard (Frost and Gross, 1993; Samuels et al., 2007). In addition, it was found that individuals with OCD who hoard have an earlier age of symptom onset (Fontenelle, et al., 2004; Samuels et al., 2007), suffer from greater levels of impairment (Lochner et al., 2005), have a lower quality of life (Fontenelle et al., 2010) and exhibit higher comorbidity rates with Axis I and II disorders, and tend to display less insight to the severity of their symptoms (Pertusa et al., 2008; Steketee and Frost, 2003). Individuals with OCD who hoard, when compared to those who do not, have also been found to respond less well to cognitive behavioral therapy as it applies to OCD (Abramowitz et al., 2003; Mataix-Cols et al., 2002). Instead, specifically tailored cognitive behavioral therapy, that does not necessarily resemble that used for other symptoms of OCD, has been found more effective for hoarding (Steketee et al., 2010). Hoarders may also exhibit a different pattern of neural activity. One study found that when compared to a non-OCD control group, individuals with OCD and hoarding behavior had significantly lower glucose metabolism in the posterior cingulate gyrus and cuneus, whereas those with non-hoarding OCD had higher glucose metabolism in the bilateral thalamus and caudate than normal controls. Those with hoarding also had significantly lower glucose metabolism in the dorsal anterior cingulate gyrus than individuals with OCD who did not hoard (Saxena et al., 2004). The authors suggested that these differences may help to explain previous findings that those who compulsively hoard respond less well than individuals with OCD without hoarding to psychopharmacological medication, specifically to serotonin reuptake inhibitors (Mataix-Cols et al., 1999). In a study comparing three groups—individuals diagnosed with OCD and hoarding, individuals with OCD without hoarding, and individuals displaying hoarding symptoms alone—Grisham et al. (2005) found that the pure hoarding group exhibited significantly lower levels of negative effect, depression, anxiety, and stress. Hoarding has also been found to have weaker correlations with common symptoms of OCD when compared to how those symptoms correlated with each other (Abramowitz et al., 2008; Wu and Watson, 2005). Abramowitz et al. (2008) also found that although individuals with OCD scored higher than individuals with other anxiety disorders and healthy controls on non-hoarding symptoms, there was no difference in scores for hoarding symptoms. Finally, Abramowitz et al. (2008) found the weakest factor loadings for measures of hoarding among a set of measures of obsessive–compulsive symptoms. All of these findings support the notion of conceptualizing hoarding behavior as a phenomenon distinct from OCD rather than one on a list of common OCD symptoms. In addition to these observed differences between hoarding and other symptoms of OCD, it has been noted that hoarding is generally less responsive to treatment (Pertusa et al., 2010). One variable examined in OCD that is related to a poorer prognosis is overvalued ideation (OVI). Overvalued ideation refers to an individual’s degree of the belief that their obsessions and associated compulsions represent reasonable thoughts and responses to the environment (Kozak and Foa, 1994; Neziroglu et al., 1999, 2004). This type of reasoning may be particularly common among individuals who hoard, as many believe strongly in the importance of acquiring and keeping their possessions as well as in the unacceptability of parting with them. This may explain why those who hoard can be particularly difficult to engage in treatment – often
arriving reluctantly due only to the persistence of their family members – as well as difficult to treat effectively once treatment is initiated (Neziroglu et al., 2004). Recent research has also begun to conceptualize differences between hoarding obsessions and hoarding compulsions (Rachman et al., 2009). Rachman et al. (2009) indicate that the experience of hoarding for the individual who hoards is nothing like the experience OCD patients have in their obsessions and compulsions. It is also noted that the compulsions of OCD individuals are stereotyped and specific day after day and the obsessions are recurrent, intrusive, unwanted and often repugnant. Thoughts of hoarders are not unwanted and intrusive and they do not engage in compulsions that are anxiety provoking. Rachman et al. (2009) state that the behaviors and emotional processes of compulsive hoarders are significantly different from those with OCD. The acquisition and protection of possessions is not distressing, but the clutter itself can be frustrating. It is the discarding of materials that is a major obstacle, and this has no resemblance to OCD compulsions (Rachman et al., 2009). A number of distinct lines of inquiry have all suggested that hoarding may be a distinct diagnostic entity (Pertusa et al., 2010). These include the aforementioned points, as well as basic biological processes. Lochner et al. (2005) identified a genotype more prevalent in those with OCD who experience hoarding symptoms than those with OCD without hoarding symptoms or other comparison groups. Saxena (2007) illustrated that not only does hoarding severity fail to correlate with the severity of other OCD symptoms, but neither do hoarders show more obsessive compulsive personality disorder traits than comparison samples (Steketee and Frost, 2003), and in fact, many hoarders do not demonstrate other OCD-related symptoms. Because the majority of research has examined the clinical characteristics of individuals with hoarding within the context of OCD (comparing OCD individuals with and without hoarding), the aim of the present investigation is to add to the small number of studies investigating hoarding as a distinct phenomenon. Based on the literature reviewed, we hypothesized that individuals with hoarding would show higher levels of overvalued ideation, but lower levels of obsessive–compulsive symptoms and other psychopathological signs and symptoms. However, given that it has been observed that some individuals who hoard also meet criteria for OCD, we examined three groups: (1) individuals diagnosed with OCD with no hoarding symptoms, (2) individuals who hoard but otherwise have no symptoms of OCD, and (3) individuals who hoard and meet criteria for OCD. It was expected that the group who met criteria for OCD who also had hoarding symptoms would show higher levels of OVI and lower levels of ancillary psychopathology symptoms when compared to those with OCD alone. It was hypothesized that given previous evidence cited above and consideration in DSM-V we hypothesize that hoarding may be a distinct phenomena in its own that is unrelated to OCD.
2. Method 2.1. Participants and procedure The participants were 148 patients who sought treatment for either obsessive–compulsive or hoarding symptoms at the Bio-Behavioral Institute (BBI), a well-recognized facility for the treatment of anxiety and mood disorders in Great Neck, New York. All participants completed informed consent prior to evaluation for the study. There were 102 participants who were diagnosed with OCD without significant hoarding symptoms (OCD-only group), 21 who were diagnosed with hoarding but without meeting criteria for a diagnosis of OCD (hoarding-only group), and 25 who were diagnosed with OCD as well as a clinically significant hoarding problem (combined group). The sample was recruited over the course of several years following diagnosis by a licensed psychologist trained in assessment and treatment of both OCD and hoarding.
F. Neziroglu et al. / Psychiatry Research 200 (2012) 35–40 Completion of the study instruments was part of the routine evaluation process at BBI. All participants provided informed consent for their questionnaires to be used for research purposes. DSM-IV-TR (APA, 2000) criteria were used to diagnose patients with OCD. In addition, The Padua Inventory (Sanavio, 1988) and Yale–Brown Obsessive– Compulsive Scale Symptom Checklist (Y–BOCS SC; Goodman et al., 1989a,b) were used to support diagnoses of the OCD-only group. The severity of OCD for this group was determined by the Yale–Brown Obsessive–Compulsive Scale (Y–BOCS; Goodman, et al., 1989a,b). In order to establish a clinical hoarding problem irrespective of any other obsessive–compulsive symptoms, Frost and Hartl’s (1996) diagnostic criteria for hoarding was applied as follows: (1) the individual acquires and fails to discard large numbers of possessions which appear to be useless or of limited value; (2) the individual’s living space is sufficiently cluttered as to preclude normal use and activities; (3) the individual experiences significant distress or impairment in functioning. In addition, pictures taken of the home, as well as home visits were used to substantiate the Frost and Hartl (1996) criteria. Only pictures of the homes of hoarders were used to provide evidence of hoarding and to validate the diagnosis. Family members also indicated that hoarding was the principle reason for seeking treatment at the Bio-Behavioral Institute. Data collected from the Savings Inventory-Revised (SI-R; Frost et al., 2004) was used to support diagnoses. Finally, the OCD with hoarding group was diagnosed using all of the aforementioned criteria, both for OCD and for Hoarding. The OCD-only group was comprised of 54 males and 48 females, with a mean age of 31.7 years (S.D. ¼14.0). The hoarding-only group was comprised of seven males and 14 females, with a mean age of 53.7 years (S.D. ¼ 15.8). The third group, those with both OCD and hoarding, consisted of nine males and 16 females, with a mean age of 49.2 years (S.D. ¼ 13.0). There was a significant group effect for age, F (2, 145)¼ 30.86, p o 0.001, with the OCD-only participants being significantly younger, on average, than those in both hoarding groups. This is consistent with previous findings that individuals seeking treatment for hoarding tend to be older than their non-hoarding counterparts presenting with OCD (Steketee and Frost, 2006).
2.2. Materials 2.2.1. Yale–Brown Obsessive–Compulsive Scale The Yale–Brown Obsessive–Compulsive Scale (Y–BOCS; Goodman et al., 1989a,b) is a semi-structured interview that assesses obsessions and compulsions, as well as generates a total score. There are five identical items for each subscale, assessing frequency, distress, social/occupational interference, resistance, and control over either obsessions or compulsions. Each item is rated from zero to four, with higher scores indicative of greater symptomatology. Factor analytic findings have confirmed the validity of the two distinct subscales (i.e., obsessions and compulsions) and therefore the present results are presented below for both scales (Amir et al., 1997; McKay et al., 1995, 1998). The psychometric properties of the measure have been well established (Taylor et al., 2010).
2.2.2. The Padua Inventory The Padua Inventory (Sanavio, 1988) consists of 60 items describing common obsessive and compulsive behaviors and was developed for administration to clinical and non-clinical samples. Internal consistency and one-month reliability has been found to be satisfactory. Concerning validity, the Padua Inventory has been shown to correlate significantly with other measures of OCD such as the Maudsley Obsessional–Compulsive Questionnaire (r¼ 0.70) and the Leyton Obsessional–Compulsive Inventory (r¼ 0.71 with Symptom scales; r¼ 0.66 with Trait scales). Four factors have been identified: impaired control of mental activities, becoming contaminated, checking behaviors, and urges and worries of losing control over motor behaviors.
2.2.3. Overvalued Ideas Scale The Overvalued Ideas Scale (OVIS; Neziroglu et al., 1999) is an 11-item clinician administered scale that assesses the extent to which a patient holds his or her obsessional belief to be true. Subjective characteristics of the belief, including strength, reasonableness, fluctuation over time, accuracy, agreement of others, effectiveness of compulsions, insight, and strength of resistance are assessed on separate 10-point Likert scales. The average of the first 10 items provides an estimate of one’s degree of overvalued ideas, with higher scores representing greater levels of OVI. The final item is an indication of the duration of the main belief. Reliability and validity data have indicated an internal consistency of a ¼ 0.95 and a test–re-test reliability, over a period of four weeks, of r ¼0.93. The obsessional beliefs indentified by individuals with compulsive hoarding were generally similar to those noted on the Savings Cognitions Scale (Frost et al., 2004). Some examples from the participant sample include, ‘‘throwing out the newspapers may mean getting rid of information I need in the future,’’ and ‘‘I love the belongings of my late husband and I could not tolerate discarding them; it would be like throwing away all of my memories.’’
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2.2.4. Beck Depression Inventory-II The Beck Depression Inventory-II (BDI-II; Beck et al., 1996a,b is a 21-item measure of the intensity of signs and symptoms typically associated with depression. Each item is rated from zero (neutral) to three (severe symptomatology). Numerous studies have supported the good psychometric status of the BDIII. Internal consistency has shown to be high (a ¼ 0.91) and test re-test reliability also (a ¼ 0.93). 2.2.5. Beck Anxiety Inventory The Beck Anxiety Inventory (BAI; Beck et al., 1988) is a 21-item measure of the severity of anxious symptoms (Beck and Steer, 1993). Items are rated in a similar fashion to the BDI-II, and assess symptoms and cognitions associated with anxiety. The reliability and validity of the BAI are well established for both clinical and non-clinical samples (Beck and Steer, 1993). It has shown high internal consistency (a ¼0.92), and test–re-test reliability over one week of r(81)¼ 0.75 (Beck et al., 1988). 2.2.6. Saving Cognitions Inventory-Revised The Saving Cognitions Inventory-Revised (SCI-R; Frost et al., 2004) is a 24-item scale measuring cognitions related to hoarding behaviors. It has four subscales: memory for possessions, control over possessions, responsibility for possessions, and emotional attachment to possessions. Alpha coefficients ranged from good to excellent (0.86–0.95) for each of the subscales, and was 0.96 for the item total score. Inter-item correlations were also acceptable and ranged from 0.40 to 0.87 (Frost et al., 2004). 2.2.7. Saving Inventory-Revised The Saving Inventory-Revised (SI-R; Frost et al., 2004) is a 23-item scale measuring hoarding behaviors. There are three factors in this scale: clutter, difficulty discarding, and acquisition. Test–re-test reliability was high, r¼ 0.86 for the total score, 0.89 for difficulty discarding, 0.90 for clutter, and 0.78 for acquisition (Frost et al., 2004).
3. Results A series of one-way analyses of covariance (ANCOVAs), with age and sex as covariates, were run comparing the three groups of participants on the Y–BOCS, Padua Inventory, BDI-II, BAI, and OVIS, as well as the two subscales of the Y–BOCS, yielding a total of seven comparisons. An additional two ANCOVAs were run comparing just the two hoarding groups on the SCI-R and SI-R. See Table 1 for means and S.D.s for each measure, broken down by group, as well as the results of the group difference tests. The False Discovery Rate (FDR; Benjamini and Hochberg, 1995) was used to correct for Type I error. All the outcome measures and comparisons yielded statistical significance. The ANCOVAs comparing the two hoarding groups on the SI-R and SCI-R were not included in this correction method because they represented a different set of group comparisons. 3.1. Obsessive–compulsive symptoms A significant group effect was found for the Y–BOCS total score, F(2, 143) ¼17.68, p o0.001, Z2 ¼ 0.23, the Y–BOCS Obsessions subscale, F(2, 143)¼23.46, po.0001, Z2 ¼0.28, the Y–BOCS compulsions subscale, F(2, 143) ¼9.47, p o0.001, Z2 ¼0.14, and the Padua Inventory, F(2, 143)¼ 5.27, po0.01, Z2 ¼0.08. Pairwise comparison follow-up analyses, using the FDR correction, revealed that in all cases, the hoarding-only group scored significantly lower on these measures of general OCD symptomatology than both the OCD-only group and the combined group. On the Y–BOCS-obsessions scale only, the combined group also scored lower than the OCD-only group (p o0.05). However, even in this case, the difference between the hoarding-only group and each of the other two groups was clearly the more robust finding. 3.2. Affective measures On the BDI-II, there was a significant group effect on depressive symptomatology, F(2, 143)¼6.31, po0.01, Z2 ¼ 0.09. Follow-up
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Table 1 Means by group on study measures with tests for group differences. Measure
Y–BOCS: total score Y–BOCS: obs. Y–BOCS: comp. Padua inventory BAI BDI OVIS SCI-R SI-R
Mean (S.D.) OCD group
Hoarding group
Combined group
24.34 (7.27) 12.81 (3.54) 11.56 (4.36) 36.90 (24.25) 18.58 (12.03) 20.38 (12.13) 4.77 (1.70)
9.23 3.77 5.46 11.21 8.67 11.29 6.28 79.12 58.24
21.29 10.05 11.00 37.90 15.96 23.30 6.22 82.46 54.53
(6.60) (3.77) (3.69) (11.71) (9.11) (7.14) (1.65) (26.73) (15.82)
(9.13) (5.03) (4.88) (23.45) (11.54) (13.91) (1.45) (35.46) (21.82)
F
Z2
17.68nnn 23.46nnn 9.47nnn 5.27nn 4.34n 6.31nn 9.29nnn 0.23 0.02
0.23 0.28 0.14 0.08 0.06 0.09 0.17 0.01 0.00
Note: Y–BOCS¼ Yale–Brown Obsessive–Compulsive Scale; Obs. ¼ Obsessions Scale; Com. ¼ Compulsions Scale; OVIS¼ Overvalued Ideas Scale; BDI¼ Beck Depression Inventory-II; BAI¼ Beck Anxiety Inventory, SCI-R ¼Saving Cognitions Inventory-Revised; SI-R ¼Saving Inventory-Revised. y p o 0.10. p o0.05. po 0.01. nnn p o 0.001. n
nn
analyses again revealed significant differences, with the hoardingonly group again scoring lower than both of the OCD groups and no significant difference found between the latter two groups. The same trend was evident when comparing the groups on symptoms of anxiety, as there was also a significant group effect on the BAI, F(2, 143)¼4.34, po0.05, Z2 ¼ 0.06. Pairwise comparisons indicated that the hoarding-only group reported significantly less anxiety than both of the other groups. No significant differences were observed between the OCD only and OCD with hoarding groups. 3.3. Overvalued ideas There was a significant group effect on the OVIS, F(2, 143) ¼ 9.29, po0.001, Z2 ¼0.17. Unlike the follow-up analyses reported above in which the hoarding-only group was consistently found to be the one generally driving the group effect, on this measure of overvalued ideas, the OCD-only group scored significantly lower than both the hoarding-only group and the combined group. There was no statistical difference between the latter two groups. 3.4. Hoarding symptomatology The hoarding-only and OCD with hoarding groups were also compared on the SI-R and SCI-R. No significant group differences were found for either measure. As a follow-up to ensure that no specific differences were missed, additional ANCOVAs (with age and sex as covariates) were conducted on the four subscales of the SCI-R and the three subscales of the SI-R. No significant group differences were found. The SI-R and SCI-R, which assess behaviors and cognitions associated with hoarding, could be viewed as simply a proxy for overvalued ideation. In order to determine whether there are distinctions between the aspects of psychopathology assessed with the OVI, ANCOVA was conducted whereby the OVI was compared between the hoarding-only and OCD with hoarding groups, while controlling for SI-R and SCI-R. These analyses revealed that the OVI accounts for unique variance when controlling for the SI-R (F(1, 44)¼7.92, p o0.01) and when controlling for the SCI-R (F(1, 44) ¼10.27, po0.001). 4. Discussion The present study was an investigation of the extent to which individuals with compulsive hoarding differ from those with
obsessive–compulsive disorder (OCD). Hoarding behavior has been considered a part of OCD as a subtype based on factor and cluster analytic research (McKay et al., 2004). However, more recent conceptualizations of hoarding have suggested that specific mechanisms distinguish it from OCD, with recommendations that it form a separate diagnosis (Pertusa et al., 2010). The present investigation adds to the growing literature that shows significant phenomenological differences between hoarding and OCD by comparing three groups: OCD-only, hoarding-only, and combined hoarding and OCD. Consistent with previous findings (e.g., Steketee and Frost, 2006), hoarders were found to be older, on average, than those diagnosed with OCD only. This may be a function of both the time it takes for accumulation of material items to reach levels that create impairment, as well as the tendency of those who hoard to avoid treatment (Neziroglu et al., 2004). Results indicated that the participants with hoarding only endorsed significantly fewer obsessive and compulsive symptoms than both the OCD-only group and the combined group. In other words, the presence of diagnosis of OCD predicted much higher scores on obsessive–compulsive symptomatology, irrespective of hoarding behavior. Furthermore, if hoarding did represent a subtype of OCD, one might expect those in the combined OCD and hoarding group to score higher than the OCD-only group due to the presence of additional OCD symptoms. This was not the case for any of these measurements. The strength of our threegroup approach is evident in these results; previous investigations that have suggested that individuals with hoarding do not differ from those with OCD (e.g., Frost et al., 2000) generally compared hoarders to non-hoarders, but with both groups meeting criteria for OCD. Pure hoarders scored quite low on two common measures of OCD symptoms, and the presence of clinical hoarding behavior did not predict a higher level of overall OCD symptomatology in those with the OCD diagnosis. These results support the notion that hoarding is better conceptualized as distinct from the diagnosis of OCD. Next, the three groups were compared on general levels of depressive and anxious symptoms as measured by the BDI-II and the BAI, respectively. On both measures, the hoarding-only group again scored significantly lower than both the OCD-only group and the combined group, whereas the latter two groups were roughly equivalent, suggesting much less affective disturbance for those with hoarding only. This is consistent with Grisham and Barlow (2005) finding that those who hoard without other OCD symptoms reported significantly less anxiety, worry, stress, and negative affect when compared to those with OCD. With respect
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to depression, our findings are not consistent with other literature showing that individuals with hoarding have higher levels of depression (discussed in Pertusa et al., 2010). Overvalued ideation, an important concept traditionally applied to those with obsessive–compulsive behavior (i.e., Kozak and Foa, 1994), was also examined. This is a measure of the strength of conviction in one’s beliefs, such as, ‘‘it is important to keep these papers just in case I need them in the future, if I do not have my husband’s belongings I will not remember all the good time we sharedy’’ Whereas the hoarding-only group stood out from the remaining two groups in all of the comparisons described thus far, when compared on the Overvalued Ideation Scale (OVIS), it was the OCD-only group that exhibited significantly fewer overvalued ideas than both the hoarding-only group and the combined group. Although the content of the belief may be different between the OCD-only and Hoarding-only group, it is not the content of the belief that is important but rather how strongly one believes in the thought. It is the strength of the conviction in a belief, regardless of content, that is important to determine how easy or difficult it may be to change the belief. Additional analyses where assessments of hoarding (the SI-R and SCI-R) were controlled showed that the OVI contributed uniquely to the difference between the OCD with hoarding compared to the hoarding only groups. Across all groups, it was the participants with hoarding (with or without OCD) who scored higher on this measure. This finding is consistent with reports of individuals who enter treatment for hoarding being more resistant to treatment. Although these individuals may present with many fewer symptoms of anxiety, and obsessionality, as well as fewer compulsive behaviors, their strong belief in the appropriateness of their appraisals of their possessions may lead to greater difficultly with challenging these thoughts and giving up their accumulated possessions. This finding is limited to the hoarding only and OCD with hoarding groups. The SI-R and SCI-R were examined to determine hoarding symptomology between the two hoarding groups. Because there was no difference between the hoarding only and OCD with hoarding groups on this measures this indicates that the diagnosis of hoarding was appropriate and that any differences between these two groups was driven by the OCD symptoms, e.g., more anxiety, depression when OCD is present. The present investigation builds on previous studies emphasizing the phenomenological differences between those individuals with hoarding and those with OCD. By self-report, the hoarding population is less anxious, less depressed, experiences lower obsessional ideation, and engages in fewer compulsive behaviors. Moreover, those who hoard generally believe quite strongly in the rationale for accumulating and saving. It may be that a primary factor in the tendency of these individuals to avoid treatment is that they do not perceive it to be a significant problem. However, case studies suggest that hoarding can be extremely deleterious to an individual in terms of the monetary cost (e.g., additional storage space, replacing inaccessible items, and repairs associated with deteriorating housing, accumulation of possessions), physical risk (e.g., treacherous living conditions, fire hazards, and blocked exits), interpersonal relationship conflicts (e.g., inability to entertain guests and significant anger from cohabitating family members), and even legal problems should government agencies become aware of the living conditions. Nevertheless, many who suffer in these circumstances only seek treatment under strong pressure from family members (Neziroglu et al., 2004). This stark contrast between perception and reality further underscores the notion of conceptualizing and treating compulsive hoarding as a distinct disorder. There are several limitations worth noting. First, there was no accounting for other comorbid conditions. While the findings
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consistently showed that individuals with hoarding had higher levels of OVI, and lower levels of OCD symptoms as well as ancillary psychopathology, the presence of comorbid conditions or signs may have impacted the results. Further, while it was implied that individuals with hoarding only and those with OCD accompanied by hoarding showed higher levels of OVI it is unclear whether there is a distinction in treatment outcome between these two groups. In addition, while the diagnoses were not conducted using available structured interviews, the diagnoses were rendered using the available criteria for hoarding as available in the literature and further verified using case conference. Future research should rely on recently developed structured interviews for establishing the presence of hoarding disorder (Tolin et al., 2010). In addition, the sample was relatively small and future research is warranted with larger groups to ensure that variability is adequately accounted for and differences between the groups may be more validly attributed to distinct features of hoarding pathology. Finally, the present sample included only individuals with hoarding who sought treatment, and was relatively small in size. Future research is warranted to determine whether the presence of hoarding in conjunction with OCD presents a barrier to treatment, among individuals actively seeking treatment as well as those who are referred for treatment under duress, such as by family pressure or due to court mandate (such as in animal hoarding, where there are higher level of legal consequences; Frost et al., 2011). In conclusion, the findings from this study contribute to the growing body of research that shows hoarding to be distinct from OCD.
Acknowledgments The authors would like to thank Jonathan Reinharth and Jennifer Wilson for their assistance in data collection and entry.
References Abramowitz, J.S., Franklin, M.E., Schwartz, S.A., Furr, J.M., 2003. Symptom presentation and outcome of cognitive-behavioral therapy for obsessive– compulsive disorder. Journal of Counseling and Clinical Psychology 71, 1049–1057. Abramowitz, J.S., Wheaton, M.G., Storch, E.A., 2008. The status of hoarding as asymptom of obsessive–compulsive disorder. Behaviour Research and Therapy 46, 1026–1033. American Psychiatric Association, 2000. Diagnostic and Statistical Manual of Mental Disorders, fourth ed., Text Revision. Author, Washington, DC. Amir, N., Foa, E.B., Coles, M., 1997. Factor structure of the Yale–Brown obsessive– compulsive scale. Psychological Assessment 9, 312–316. Baer, L., 1994. Factor analysis of symptom subtypes of obsessive compulsive disorder and their relation to personality and tic disorders. Journal of Clinical Psychiatry 55, 18–23. Beck, A.T., Epstein, N., Brown, G., Steer, R.A., 1988. An inventory for measuring clinical anxiety: psychometric properties. Journal of Consulting and Clinical Psychology 56, 893–897. Beck, A.T., Steer, R.A., 1993. Beck anxiety inventory. Harcourt, Brace and Co, San Antonia. Beck, A.T., Steer, R.A., Brown, G.K., 1996a. Manual for the Beck depression inventory-II. Psychological Corporation, San Antonio, TX. Beck, A.T., Steer, R.A., Ball, R., Ranieri, W., 1996b. Comparison of Beck depression inventories – IA and – II in psychiatric outpatients. Journal of Personality Assessment 67, 588–597. Benjamini, Y., Hochberg, Y., 1995. Controlling the false discovery rate: a practical and powerful approach to multiple testing. Journal of the Royal Statistical Society, Series B 57, 289–300. Fontenelle, I.S., Fontenelle, L.F., Borges, M.C., Prazeres, A.M., Range, B.P., Mendelowicz, M.V., Versiani, M., 2010. Quality of life and symptom dimensions of patients with obsessive–compulsive disorder. Psychiatry Research 179, 198–203. Fontenelle, L.F., Mendlowicy, M.V., Soarez, I.D., Versiani, M., 2004. Patients with obsessive–compulsive disorder and hoarding symptoms: a distinctive clinical subtype? Comprehensive Psychiatry 45, 375–383. Frankenburg, F., 1984. Hoarding in anorexia nervosa. British Journal of Medical Psychology 57, 57–60.
40
F. Neziroglu et al. / Psychiatry Research 200 (2012) 35–40
Frost, R.O., Gross, R.C., 1993. The hoarding of possessions. Behaviour Research and Therapy 31, 367–381. Frost, R.O., Hartl, T.L., 1996. A cognitive-behavioral model of compulsive hoarding. Behaviour Research and Therapy 34, 341–350. Frost, R.O., Krause, M., Steketee, G., 1996. Hoarding and obsessive compulsive symptoms. Behaviour Modification 20, 116–132. Frost, R.O., Patronek, G., Rosenfield, E., 2011. Comparison of object and animal hoarding. Depression and Anxiety 28, 885–891. Frost, R.O., Steketee, G., Grisham, J., 2004. Measurement of compulsive hoarding: saving inventory revised. Behaviour Research and Therapy 42, 1163–1182. Frost, R.O., Steketee, G., Williams, L.F., Warren, R., 2000. Mood, personality disorder symptoms, and disability in obsessive compulsive hoarders: a comparison with clinical and non-clinical controls. Behaviour Research and Therapy 38, 1071–1081. Goodman, W.K., Price, L.H., Rasmussen, S.A., Mazure, C., Fleischmann, R.L., Hill, C.L., Hening, G.R., Charney, D.S., 1989a. The Yale–Brown Obsessive Compulsive scale, I: development, use, and reliability. Archives of General Psychiatry 46, 1006–1011. Goodman, W.K., Price, L.H., Rasmussen, S.A., Mazure, C., Delgado, P., Heninger, G.R., Dennis, S., Charney, D.S., 1989b. The Yale–Brown obsessive compulsive scale, II: validity. Archives of General Psychiatry 46, 1012–1016. Grisham, J.R., Barlow, D.H., 2005. Compulsive hoarding: current research and theory. Journal of Psychopathology and Behavioral Assessment 27, 45–52. Grisham, J.R., Brown, T.A., Liverant, G.I., Campbell-Sills, L., 2005. The distinctiveness of compulsive hoarding from obsessive–compulsive disorder. Journal of Anxiety Disorders 19, 767–779. Hanna, G.L., 1995. Demographic and clinical features of obsessive–compulsive disorder in children and adolescents. Journal of American Academy of Child and Adolescent Psychiatry 34, 19–27. Hwang, J.P., Tsai, S.J., Yang, C.H., Liu, K.M., Lirng, J.F., 1998. Hoarding behavior in dementia. A preliminary report. American Journal of Geriatric Psychiatry 6, 285–289. Jang, J.H., Kim, H.S., Ha, T.H., Shin, N.Y., Kang, D.H., Choi, J.S., Ha, K., Kwon, J.S., 2010. Nonverbal memory and organization dysfunctions are related with distinct symptom dimensions in obsessive–compulsive disorder. Psychiatry Research 180, 93–98. Kozak, M.J., Foa, E.B., 1994. Obsessions, overvalued ideas, and delusions in obsessive–compulsive disorder. Behaviour Research and Therapy 32, 343–353. Lochner, C., Kinnear, C.J., Hemmings, S.M.J., Seller, C., Niehaus, D.J.H., Knowles, J.A., et al., 2005. Hoarding in obsessive–compulsive disorder: clinical and genetic correlates. Journal of Clinical Psychiatry 66, 1155–1160. Markarian, Y., Larson, M.J., Aldea, M.A., Baldwin, S.A., Good, D., Berkeljon, A., Murphy, T.K., Storch, E.A., McKay, D., 2010. Multiple pathways to functional impairment in obsessive–compulsive disorder. Clinical Psychology Review 30, 78–88. Mataix-Cols, D., Marks, I.M., Griest, J.H., Kobak, K.A., Baer, L., 2002. Obsessive– compulsive symptom dimensions as predictros of compliance with and response to behaviour therapy: results from a controlled trial. Psychotherapy and Psychosomatics 71, 255–262. Mataix-Cols, D., Rauch, S.L., Manzo, P.A., Jenike, M.A., Baer, L., 1999. Use of factoranalyzed symptom dimensions to predict outcome with serotonin reuptake inhibitors and placebo in the treatment of obsessive–compulsive disorder. American Journal of Psychiatry 156, 1409–1416. McKay, D., Abramowitz, J., Calamari, J., Kyrios, M., Radomsky, A., Sookman, D., Taylor, S., Wilhelm, S., 2004. A critical evaluation of obsessive–compulsive disorder subtypes: symptoms versus mechanisms. Clinical Psychology Review 24, 283–313.
McKay, D., Danyko, S., Neziroglu, F., Yaryura-Tobias, J.A., 1995. Factor structure of the Yale–Brown obsessive–compulsive scale: a two dimensional measure. Behaviour Research and Therapy 33, 865–869. McKay, D., Neziroglu, F., Stevens, K., Yaryura-Tobias, J.A., 1998. The Yale–Brown obsessive–compulsive scale: confirmatory factor analytic findings. Journal of Psychopathology and Behavioral Assessment 20, 265–274. Neziroglu, F., Bubrick, J., Yaryura-Tobias, J.A., 2004. Overcoming compulsive hoarding. New Harbinger Press, California. Neziroglu, F., Pinto, A., Yaryura-Tobias, J.A., McKay, D., 2004. Overvalued ideation as a predictor of fluvoxamine response in patients with obsessive–compulsive disorder. Psychiatry Research 125, 53–60. Neziroglu, F., Stevens, K., McKay, D., Todaro, J., Yaryura-Tobias, J.A., 1999. Development of the overvalued ideas scale: reliability and validity. Behaviour Research and Therapy 37, 881–902. Pertusa, A., Frost, R.O., Fullana, M.A., Samuels, J., Steketee, G., Tolin, D.F., Saxena, S., Leckman, J.F., Mataix-Cols, D., 2010. Refining the diagnostic boundaries of compulsive hoarding: a critical review. Clinical Psychology Review 30, 371–386. Pertusa, A., Fullana, M.A., Singh, S., Alonso, P., Menchon, J.M., Mataix-Cols, D., 2008. Compulsive hoarding: OCD symptom, distinct clinical syndrome, or both? American Journal of Psychiatry 165, 1289–1298. Rachman, S., Elliott, C.M., Shafran, R., Radomsky, A.S., 2009. Separating hoarding from OCD. Behaviour Research and Therapy 47, 520–522. Rasmussen, S., Eisen, J., 1992. The epidemiology and clinical features of obsessive compulsive disorder. The Psychiatric Clinics of North America 15, 743–758. Samuels, J.F., Bienvenu, O.J., Pinto, A., Fyer, A.J., McCracken, J.T., Rauch, S.L., et al., 2007. Hoarding in obsessive–compulsive disorder: results from the OCD collaborative genetics study. Behaviour Research and Therapy 45, 673–686. Sanavio, E., 1988. Obsessions and compulsions: the Padua inventory. Behaviour Research and Therapy 26, 169–177. Saxena, S., 2007. Is compulsive hoarding a genetically and neurobiologically discretesyndrome? Implications for diagnostic classification. American Journal of Psychiatry 164, 380–384. Saxena, S., Brody, A.L., Maidment, K.M., Smith, E.C., Zohrabi, N., Katz, E., et al., 2004. Cerebral glucose metabolism in obsessive–compulsive hoarding. American Journal of Psychiatry 161, 1038–1048. Stein, D.J., Lasylo, B., Marasi, E., Seedat, S., Potocnik, F., 1997. Hoarding symptoms in patients on a geriatric psychiatry inpatient unit. South African Medical Journal 87, 1138–1140. Steketee, G., Frost, R.O., 2003. Compulsive hoarding: current status of the research. Clinical Psychological Review 23, 905–927. Steketee, G., Frost, R.O., 2006. Compulsive hoarding and acquiring: therapist guide (treatments that work). Oxford University Press, New York. Steketee, G., Frost, R.O., Tolin, D.F., Rasmussen, J., Brown, T.A., 2010. Waitlist controlled trial of cognitive behavior therapy for hoarding disorder. Depression and Anxiety 27, 476–484. Taylor, S., Abramowitz, J.S., McKay, D., 2010. Obsessive–compulsive disorder. In: Antony, M.M., Barlow, D.H. (Eds.), Handbook of Assessment and Treatment Planning for Psychological Disorders, second ed. The Guilford Press, New York, pp. 267–300. Tolin, D.F., Frost, R.O., Steketee, G., 2010. A brief interview for assessing compulsive hoarding: the hoarding rating scale-interview. Psychiatry Research 178, 147–152. Tolin, D.F., Villavicencio, A., Umbach, A., Kurtz, M.M., 2011. Neuropsychological functioning in hoarding disorder. Psychiatry Research 189, 413–418. Wu, K., Watson, D., 2005. Hoarding and its relation to obsessive–compulsive disorder. Behaviour Research and Therapy 43, 897–921.