It is suggested that the different psychological vulnerability factors of intolerance of uncertainty (IU), anxiety sensitivity (AS) and distress tolerance (DT) may be in important in hoarding disorder (HD). However, the extent to which these factors are specific to HD compared with other disorders remains unclear.

The current study aimed to investigate differences in IU, AS and DT in three groups: HD (n=66), obsessive compulsive disorder (OCD; n=59) and healthy controls (HCs; n=63).

Participants completed an online battery of standardised self-report measures to establish the independent variable of group membership (HD, OCD and HC) and the dependent variables (IU, AS and DT).

A MANOVA analysis indicated statistically significant differences in IU, AS and DT between the clinical groups and HCs. Follow-up analyses showed no statistically significant differences between the HD and OCD group for any of the three constructs. The results remained the same when examining the effects of co-morbid HD and OCD. An unexpected finding was the trend for IU, AS and DT to be more severe when HD and OCD were co-morbid.

The evidence suggests the absence of a specific relationship between IU, AS or DT in HD and instead is consistent with existing research which suggests that these psychological vulnerability factors are transdiagnostic constructs across anxiety disorders. The implications of the findings are discussed.

There is suggestive evidence linking hoarding with several problems in emotional regulation, and though this is shared with OCD patients, it may not correlate to the presence of obsessive symptoms.

The present study aimed to examine self-reported deficits in emotion regulation (ER) and obsessiveness among individuals with hoarding disorder (HD) in comparison with others with obsessive compulsive disorder (OCD) and healthy controls

Twenty-two adult outpatients with HD, twenty-two with OCD and twenty-two age and gender matched healthy control (HC) participants completed the Emotion Regulation Questionnaire (ERQ) which measures respondents tendency to regulate their emotions in two ways: Cognitive Reappraisal and Expressive Suppression. They fulfilled as well the OCI-R which evaluates six groups of OCD symptoms: Washing, Checking, Ordering, Obsessing, Hoarding, and Neutralizing.

The HD and OCD groups scored higher, (p 0.04), on Cognitive Reappraisal than did the HC group. There was no significant difference between groups in Expressive Suppression. HD and HC groups scored significantly lower, (p < 0.001), in OCI-R than OCD patients.

Results suggest that OCD and HD are characterized by self-reported deficits in ER, but this relationship in HD patients is not solely attributable to obsessive symptoms.

The extent to which obsessive–compulsive and related disorders (OCRDs) are impulsive, compulsive, or both requires further investigation. We investigated the existence of different clusters in an online nonclinical sample and in which groups DSM-5 OCRDs and other related psychopathological symptoms are best placed.

Seven hundred and seventy-four adult participants completed online questionnaires including the Cambridge–Chicago Compulsivity Trait Scale (CHI-T), the Barratt Impulsiveness Scale (BIS-15), and a series of DSM-5 OCRDs symptom severity and other psychopathological measures. We used K-means cluster analysis using CHI-T and BIS responses to test three and four factor solutions. Next, we investigated whether different OCRDs symptoms predicted cluster membership using a multinomial regression model.

The best solution identified one “healthy” and three “clinical” clusters (ie, one predominantly “compulsive” group, one predominantly “impulsive” group, and one “mixed”—“compulsive and impulsive group”). A multinomial regression model found obsessive–compulsive, body dysmorphic, and schizotypal symptoms to be associated with the “mixed” and the “compulsive” clusters, and hoarding and emotional symptoms to be related, on a trend level, to the “impulsive” cluster. Additional analysis showed cognitive-perceptual schizotypal symptoms to be associated with the “mixed” but not the “compulsive” group.

Our findings suggest that obsessive–compulsive disorder; body dysmorphic disorder and schizotypal symptoms can be mapped across the “compulsive” and “mixed” clusters of the compulsive–impulsive spectrum. Although there was a trend toward hoarding being associated with the “impulsive” group, trichotillomania, and skin picking disorder symptoms did not clearly fit to the demarcated clusters.

Preliminary evidence suggests that hoarding disorder (HD) and obsessive-compulsive disorder (OCD) may show distinct patterns of brain activation during executive performance, although results have been inconclusive regarding the specific neural correlates of their differential executive dysfunction. In the current study, we aim to evaluate differences in brain activation between patients with HD, OCD and healthy controls (HCs) during response inhibition, response switching and error processing.

We assessed 17 patients with HD, 18 patients with OCD and 19 HCs. Executive processing was assessed inside a magnetic resonance scanner by means of two variants of a cognitive control protocol (i.e. stop- and switch-signal tasks), which allowed for the assessment of the aforementioned executive domains.

OCD patients performed similar to the HCs, differing only in the number of successful go trials in the switch-signal task. However, they showed an anomalous hyperactivation of the right rostral anterior cingulate cortex during error processing in the switch-signal task. Conversely, HD patients performed worse than OCD and HC participants in both tasks, showing an impulsive-like pattern of response (i.e. shorter reaction time and more commission errors). They also exhibited hyperactivation of the right lateral orbitofrontal cortex during successful response switching and abnormal deactivation of frontal regions during error processing in both tasks.

Our results support that patients with HD and OCD present dissimilar cognitive profiles, supported by distinct neural mechanisms. Specifically, while alterations in HD resemble an impulsive pattern of response, patients with OCD present increased error processing during response conflict protocols.

Treatment for hoarding disorder is typically performed by mental health professionals, potentially limiting access to care in underserved areas.

We aimed to conduct a non-inferiority trial of group peer-facilitated therapy (G-PFT) and group psychologist-led cognitive–behavioural therapy (G-CBT).

We randomised 323 adults with hording disorder 15 weeks of G-PFT or 16 weeks of G-CBT and assessed at baseline, post-treatment and longitudinally (≥3 months post-treatment: mean 14.4 months, range 3–25). Predictors of treatment response were examined.

G-PFT (effect size 1.20) was as effective as G-CBT (effect size 1.21; between-group difference 1.82 points, t = −1.71, d.f. = 245, P = 0.04). More homework completion and ongoing help from family and friends resulted in lower severity scores at longitudinal follow-up (t = 2.79, d.f. = 175, P = 0.006; t = 2.89, d.f. = 175, P = 0.004).

Peer-led groups were as effective as psychologist-led groups, providing a novel treatment avenue for individuals without access to mental health professionals.

C.A.M. has received grant funding from the National Institutes of Health (NIH) and travel reimbursement and speakers’ honoraria from the Tourette Association of America (TAA), as well as honoraria and travel reimbursement from the NIH for serving as an NIH Study Section reviewer. K.D. receives research support from the NIH and honoraria and travel reimbursement from the NIH for serving as an NIH Study Section reviewer. R.S.M. receives research support from the National Institute of Mental Health, National Institute of Aging, the Hillblom Foundation, Janssen Pharmaceuticals (research grant) and the Alzheimer's Association. R.S.M. has also received travel support from the National Institute of Mental Health for Workshop participation. J.Y.T. receives research support from the NIH, Patient-Centered Outcomes Research Institute and the California Tobacco Related Research Program, and honoraria and travel reimbursement from the NIH for serving as an NIH Study Section reviewer. All other authors report no conflicts of interest.

The Clutter Image Rating (CIR) was created to meet a gap in the research on compulsive hoarding: how to ascertain clutter level in an individual's home without a home visit, as not all clinicians have the ability to conduct a home visit. The CIR has proven itself to be both reliable and valid for use in adults with compulsive hoarding symptoms. However, there is currently a dearth of information on performance of the CIR in older adults diagnosed with hoarding disorder (HD). Because older adults have increased medical issues, including fall risks, evaluating the level of clutter in the house is especially critical in geriatric populations.

The current study was an investigation of the reliability and validity of the CIR in assessing late life HD. The internal consistency, convergent and divergent validity, and norms of the CIR were investigated in a large geriatric HD sample and compared with a midlife sample of individuals with HD. Criterion validity of the CIR was investigated through the comparison of participant ratings conducted in the clinic and clinician ratings conducted in the home.

The current study found similar levels of reliability and validity in a late life sample as in previous studies conducted in mid-life adults.

Unlike previous studies, the current study did not find a significant relationship between the CIR and the non-clutter related subscales of the Savings Inventory-Revised. The CIR appears to be both reliable and valid for assessing clutter levels in older adults diagnosed with HD.

Although severe hoarding symptoms have been considered rare among obsessive-compulsive disorder (OCD) samples, the prevalence of animal hoarding in OCD is unknown. To help clarifying this issue, we searched for cases of animal hoarding among patients attending a university OCD clinic (n=420).

Chart review.

Only two patients from our sample exhibited animal hoarding (<0.5%) and only one of them presented additional obsessive-compulsive symptoms. Both cases also collected inanimate objects, presented low insight, exhibited poor response to serotonin reuptake inhibitors and did not adhere to therapy.

There seems to be a lack of relationship between animal hoarding and OCD. However, further studies with larger numbers of patients are needed to better define their psychopathological profile and more appropriate nosological insertion.

The recent addition of hoarding disorder (HD) to the Diagnostic and Statistical Manual of Mental Health Disorders, 5th edition, has highlighted the dearth of information about the demographic, sociologic, and medical predictors of HD severity, particularly in older adults. Although there have been several previous studies examining the characteristics of older adults with HD, and one investigation of psychiatric correlates of hoarding symptom severity in non-clinical older adults, there has been little investigation about which characteristics predict hoarding symptom severity in older adults with HD.

Participants were 71 older adults who were enrolled for one of the two studies of HD at the VA San Diego Healthcare System between January 2010 and January 2014.

There were multiple differences in the predictive ability of patient characteristics between the more cognition-related symptoms of HD and the more concrete measure of clutter, including gender-based differences and anxiety severity. Further, married participants were more likely to report lower hoarding severity, and there was no significant relationship between hoarding severity and intervention attempts or hoarding and reported falls in the past three years.

Multiple predictive factors have been presented, which may result in further studies to investigate possible predictive differences in cognition and clutter symptoms of HD. Future studies should examine the possibility of the predictive factors also identified to be moderators of treatment outcomes.

A new diagnostic category, hoarding disorder (HD), has been proposed for inclusion in DSM-5. This study field-tested the validity, reliability and perceived acceptability of the proposed diagnostic criteria for HD.

Fifty unselected individuals with prominent hoarding behavior and 20 unselected, self-defined ‘collectors’ participated in thorough psychiatric assessments, involving home visits whenever possible. A semi-structured interview based on the proposed diagnostic criteria for HD was administered and scored by two independent raters. ‘True’ diagnoses were made by consensus according to the best-estimate diagnosis procedure. The percentage of true positive HD cases (sensitivity) and true negative HD cases (specificity) was calculated, along with inter-rater reliability for the diagnosis and each criterion. Participants were asked about their perceptions of the acceptability, utility and stigma associated with the new diagnosis.

Twenty-nine (58%) of the hoarding individuals and none of the collectors fulfilled diagnostic criteria for HD. The sensitivity, specificity and inter-rater reliability of the diagnosis, and of each individual criterion and the specifiers, were excellent. Most participants with HD (96%) felt that creating a new disorder would be very or somewhat acceptable, useful (96%) and not too stigmatizing (59%).

The proposed HD criteria are valid, reliable and perceived as acceptable and useful by the sufferers. Crucially, they seem to be sufficiently conservative and unlikely to overpathologize normative behavior. Minor changes in the wording of the criteria are suggested.

The DSM-5 Obsessive-Compulsive Spectrum Sub-Workgroup is recommending the creation of a new diagnostic category named Hoarding Disorder (HD). The validity and acceptability of the proposed diagnostic criteria have yet to be formally tested.

Obsessive-compulsive disorder/hoarding experts and random members of the American Psychiatric Association (APA) were shown eight brief clinical vignettes (four cases meeting criteria for HD, three with hoarding behaviour secondary to other mental disorders, and one with subclinical hoarding behaviour) and asked to decide the most appropriate diagnosis in each case. Participants were also asked about the perceived acceptability of the criteria and whether they supported the inclusion of HD in the main manual.

Altogether, 211 experts and 48 APA members completed the survey (30% and 10% response rates, respectively). The sensitivity and specificity of the HD diagnosis and the individual criteria were high (80–90%) across various types of professionals, irrespective of their experience with hoarding cases. About 90% of participants in both samples thought the criteria would be very/somewhat acceptable for professionals and sufferers. Most experts (70%) supported the inclusion of HD in the main manual, whereas only 50% of the APA members did.

The proposed criteria for HD have high sensitivity and specificity. The criteria are also deemed acceptable for professionals and sufferers alike. Training of professionals and the development and validation of semi-structured diagnostic instruments should improve diagnostic accuracy even further. A field trial is now needed to confirm these encouraging findings with real patients in real clinical settings.