Clinical Correlates of Hoarding With and Without Comorbid Obsessive-Compulsive Symptoms in a Community Pediatric Sample

Hoarding behavior and its association with mental health and functioning in a large youth sample

Hoarding behavior is prevalent in children and adolescents, yet clinicians do not routinely inquire about it and youth may not spontaneously report it due to stigma. It is unknown whether hoarding behavior, over and above obsessive-compulsive symptoms (OCS), is associated with major clinical factors in a general youth population. This observational study included N = 7054 youth who were not seeking help for mental health problems (ages 11-21, 54% female) and completed a structured interview that included evaluation of hoarding behavior and OCS, as a part of the Philadelphia Neurodevelopmental Cohort between November 2009 and December 2011. We employed regression models with hoarding behavior and OCS (any/none) as independent variables, and continuous (linear regression) or binary (logistic regression) mental health measures as dependent variables. All models covaried for age, sex, race, and socioeconomic status. A total of 374 participants endorsed HB (5.3%), most of which reported additional OCS (n = 317). When accounting for OCS presence, hoarding behavior was associated with greater dimensional psychopathology burden (i.e., higher P-factor) (β = 0.19, p < .001), and with poorer functioning (i.e., lower score on the child global assessment scale) (β = - 0.07, p < .001). The results were consistent when modeling psychopathology using binary variables. The results remained significant in sensitivity analyses accounting for count of endorsed OCS and excluding participants who met criteria for obsessive-compulsive disorder (n = 210). These results suggest that hoarding behavior among youth is associated with poorer mental health and functioning, independent of OCS. Brief hoarding-behavior assessments in clinical settings may prove useful given hoarding behavior's stigma and detrimental health associations.

Gene copy number variation and pediatric mental health/neurodevelopment in a general population

We assessed the relationship of gene copy number variation (CNV) in mental health/neurodevelopmental traits and diagnoses, physical health and cognition in a community sample of 7100 unrelated children and youth of European or East Asian ancestry (Spit for Science). Clinically significant or susceptibility CNVs were present in 3.9% of participants and were associated with elevated scores on a continuous measure of attention-deficit/hyperactivity disorder (ADHD) traits (P = 5.0 × 10-3), longer response inhibition (a cognitive deficit found in several mental health and neurodevelopmental disorders; P = 1.0 × 10-2) and increased prevalence of mental health diagnoses (P = 1.9 × 10-6, odds ratio: 3.09), specifically ADHD, autism spectrum disorder anxiety and learning problems/learning disorder (P's < 0.01). There was an increased burden of rare deletions in gene-sets related to brain function or expression in brain associated with more ADHD traits. With the current mental health crisis, our data established a baseline for delineating genetic contributors in pediatric-onset conditions.

Glutamatergic neurons and GABAergic neurons of medial prefrontal cortex control hoarding-like behavior

Hoarding disorder (HD) is a chronic disease that begins early in life and does not remission unless timely treated. A large number of factors affect the presentation of HD symptoms, including a strong possessive psychology of objects and neurocognitive functioning. However, the underlying neural mechanisms of the excessive hoarding behavior in HD are still unknown. Using viral infections and brain slice electrophysiology recordings, we found that increased glutamatergic neuronal activity and decreased GABAergic neuronal activity in medial prefrontal cortex (mPFC) accelerated the hoarding-like behavior in mice. Respectively, chemogenetic manipulation to reduce glutamatergic neuronal activity or enhance GABAergic neuronal activity could improve the hoarding-like behavioral response. These results reveal a critical role played by alterations in the activity of specific types of neurons in hoarding-like behavior, and that targeted therapies for HD may be possible by precisely modulating these types of neurons.

Co-occurring Obsessive-Compulsive Disorder and Hoarding Disorder: A Review of the Current Literature

Current research suggests obsessive-compulsive disorder (OCD) co-occurs in around 20% of people with hoarding disorder (HD). The article discusses the theoretical conceptualization of co-occurring HD and OCD (HD+OCD), highlighting similarities between the disorders that may contribute to comorbidity, such as potentially overlapping etiological factors, comorbidity profiles, and phenomenological aspects; and differences that are important to consider in differential diagnosis and conceptualization, such as belief patterns, ego-syntonicty/dystonicity, and trajectory. The combination of HD+OCD versus either disorder alone appears to be associated with a profile characterized by higher nonhoarding OCD symptoms, anxiety symptoms, depression, and tic disorders, and which may be more treatment-refractory. The authors discuss some commonly used measures to assess hoarding that may be relevant in the context of OCD, as differential diagnosis of hoarding behaviors is often difficult, and hoarding may be difficult to detect in patients with OCD, especially in children. The article ends with a discussion on considerations for the treatment of HD+OCD with cognitive-behavioral therapy, as hoarding symptoms are less likely to respond to gold-standard exposure and response prevention, and there are no established treatment protocols that are designed to treat co-occurring HD and OCD.

Prevalence and correlates of hoarding behavior and hoarding disorder in children and adolescents

Although hoarding symptoms are reported to begin in childhood and adolescence, the true prevalence of the disorder in this age group is unknown. This study aims to estimate the prevalence of hoarding disorder (HD) in children and adolescents. The present study was planned as a two-stage epidemiological research. In the first stage, the Children's Saving Inventory (CSI) and informed consent forms were delivered to a group of students' parents. In the second stage, one-on-one psychiatric interviews with a physician were planned with the families and children who had hoarding behavior (HB), as described by their parents. The DSM-5-based HD interview and the Development and Well-Being Assessment (DAWBA) diagnostic tool were used to detect prevalence of HD and comorbid psychiatric disorders. A total of 3249 children were included in the study, and 318 children and their parents were evaluated in the second stage. As a result of the second assessment, 32 out of 318 children met the HD diagnostic criteria. The estimated prevalence of HD was 0.98% (95% CI 0.7-1.4). Hoarding disorder was found more frequently in females (F/M = 3/1). After a logistic regression analysis, variables such as female sex and the presence of any psychopathology were identified as independent correlates of HD. More than half (56.2%) of the children diagnosed as having HD also had a comorbid psychiatric disorder. In the present study, the two-stage evaluation method was used in a large pediatric sample to determine the estimated prevalence of HD, as well as the factors associated with the disorder and comorbid psychiatric disorders.

Body-dysmorphic, hoarding, hair-pulling, and skin-picking symptoms in a large sample of adolescents

Few studies have investigated body-dysmorphic, hoarding, hair-pulling, and skin-picking symptoms in adolescents and how they relate to mental health, quality of life, suicide attempts, and non-suicidal self-harm. We used a quota sampling procedure and contacted 100 secondary centres in the Southeast of Spain, of which 34 participated in the study. A sample of 5,345 adolescents (12–18 years) completed dimensional measures of body-dysmorphic, hoarding, hair-pulling, and skin-picking symptoms. The proportion of adolescents with clinically significant symptoms within each symptom type was estimated and associations with other indicators of mental health examined. Clinically significant body-dysmorphic symptoms were reported by 3.7%, hoarding by 0.9%, hair-pulling by 0.7%, and skin-picking by 1.8%. Body-dysmorphic symptoms were more common in girls and in those over 14 years of age. Body-dysmorphic, hoarding, hair-pulling, and skin-picking symptoms were moderately to strongly associated with obsessive-compulsive symptoms, internalizing symptoms, externalizing symptoms, and poor quality of life. Those with significant body-dysmorphic, hoarding, hair-pulling, and skin-picking symptoms were much more likely to have attempted suicide and engaged in non-suicidal self-harm during the last twelve months than those without such symptoms. Body-dysmorphic symptoms showed the strongest associations with internalizing symptoms and poor quality of life. Limitations are the sole use of self-report and a sample from only two regions in Spain, but findings suggest that body-dysmorphic, hoarding, hair-pulling, and skin-picking symptoms are common and impairing during adolescence.

Clinical validation of the parent-report Toronto Obsessive-Compulsive Scale (TOCS): A pediatric open-source rating scale

Background

There is a need to develop a multipurpose obsessive-compulsive disorder (OCD) measure that is useful for cross disorder research and as a reliable clinical rating scale. The current study examined the psychometric properties and established clinical cutoffs for the parent-report version of the Toronto Obsessive-Compulsive Scale (TOCS), a 21-item rating scale of obsessive-compulsive traits.

Method

Participants ranged in age from 6 to 21 years old and had a primary diagnosis of OCD (n = 350, 50% female), attention-deficit/hyperactivity disorder (ADHD) (n = 820, 25% female), autism spectrum disorder (ASD) (n = 794, 22% female), or were typically developing controls (n = 391, 51% female). Confirmatory factor analyses, internal consistency reliability, and convergent and divergent validity of the TOCS were examined in the OCD group. Using various scoring approaches, receiver operating characteristic (ROC) analyses were used to establish a clinical cut-off by splitting the OCD group into a discovery sample (166 OCD cases, 164 controls) and a validation sample (184 OCD cases, 227 controls). Classification accuracy and TOCS scores were compared across OCD, ADHD, and ASD groups.

Results

The psychometric properties of the TOCS were confirmed. ROC analyses across TOCS scoring approaches in the discovery sample indicated excellent diagnostic discrimination (AUC ≥0.95, sensitivity 77%-92%, specificity 92%-98%). Established cutoffs, when applied in the independent validation sample of OCD cases and controls, showed an overall classification accuracy of 85%-90%. The TOCS total score and symptom count showed good discrimination of OCD from ADHD (AUC ≥0.86) and ASD (AUC ≥0.81). The OCD group scored significantly higher on all TOCS dimensions (except Hoarding) than the ADHD and ASD groups.

Conclusion

The TOCS is a reliable and valid rating scale with strong sensitivity and specificity in discriminating OCD cases from controls, as well as from ASD and ADHD. It is a quantitative OCD measure with important clinical and research applications, with particular relevance for cross disorder phenotyping and population-based studies.

Investigating executive functions in youth with OCD and hoarding symptoms

Executive functions (EF) deficits are hypothesized to be a core contributor to hoarding symptoms. EF have been studied in adult hoarding populations, but studies in youth are lacking. The current study compared multiple EF subdomains between youth with obsessive-compulsive disorder (OCD) and youth with OCD and hoarding symptoms. Forty youth (8-18 years old) with a primary diagnosis of OCD were recruited. Participants were divided by hoarding severity on the Child Saving Inventory (CSI) into either the "hoarding group" (upper 33.3%) or the "low-hoarding group" (lower 66.7%). Groups were compared on EF tasks of cognitive flexibility, decision-making, and inhibitory control. Youth in the hoarding group exhibited significantly higher cognitive flexibility and lowered perseveration than the low-hoarding group. Hoarding and low-hoarding groups did not differ in any other EF subdomain. Hoarding symptoms in youth with OCD were not associated with deficits in EF subdomains; instead, youth who hoard exhibited higher cognitive flexibility compared to youth with low hoarding symptoms.

The developmental origins of hoarding disorder in adolescence: a longitudinal clinical interview study following an epidemiological survey

Hoarding disorder (HD) is hypothesized to originate in childhood/adolescence but little is known about the presentation of hoarding symptoms in youth and their natural history. In this longitudinal study, we tracked and conducted in-depth psychiatric interviews with twins who participated in an epidemiological survey and screened positive on a measure of hoarding symptoms at age 15. Twins screening positive for clinically significant hoarding symptoms at age 15 (n = 42), their co-twins (n = 33), a group of screen negative twins (n = 49), and their parents underwent a clinical assessment a median of 3 years after the initial screening. The assessment included psychiatric screening, hoarding symptoms and cognitions, in-home or photographic assessment of clutter levels, parental accommodation and familial burden. None of the participants had significant levels of clutter at follow-up and thus did not meet strict criteria for HD. However, twins meeting partial criteria (i.e., DSM-5 criteria A and B) for HD (n = 28) had more psychiatric disorders and scored significantly higher on all measures of hoarding symptoms including researcher-rated levels of clutter in their homes, compared to twins who did not meet partial criteria for HD (n = 46). As currently defined in DSM-5, HD may be rare in young people. A non-negligible proportion of young people who were screen positive on hoarding symptoms at age 15 had substantial hoarding symptoms and other psychopathology at follow-up. Whether and how many of these individuals will develop full-blown HD is unknown but the results offer unique insights about the probable origins of HD in adolescence.

Serotonin system genes and hoarding with and without other obsessive-compulsive traits in a population-based, pediatric sample: A genetic association study

BACKGROUND

Hoarding, originally only considered a symptom of obsessive-compulsive disorder (OCD), is now categorized as a separate disorder in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). We studied candidate serotonergic genes and the distinctness of hoarding in children and adolescents and hypothesized that unique gene variants would be associated with hoarding alone.

METHODS

We examined obsessive-compulsive (OC) traits, including hoarding, in a total of 5,213 pediatric participants in the community. We genotyped candidate serotonin genes (5-HTTLPR polymorphism in SLC6A4 for 2,018 individuals and single nucleotide polymorphisms [SNPs] across genes SLC6A4, HTR2A, and HTR1B for 4,711 individuals). In a previous study conducted by our group in the same sample, we identified a significant association between 5-HTTLPR and hoarding in males. In this study, we examined hoarding more closely by testing the association between serotonin gene variants and hoarding traits with and without other accompanying OC traits.

RESULTS

The [L_G +S] variant in 5-HTTLPR was significantly associated with hoarding alone in males (p-value of 0.009). There were no significant findings for 5-HTTLPR in females. There were no significant findings after correction for multiple comparisons using SNP array data, but top SNP findings suggested that variation downstream of HTR1B may be implicated in hoarding alone in females.

CONCLUSIONS

Our results suggest specific serotonin gene variants are associated with hoarding traits alone, differing between sexes. Top findings are in line with our former study, suggesting that individuals with hoarding alone were driving previous results. Our paper supports hoarding disorder's new designation.

Serotonin system genes and obsessive-compulsive trait dimensions in a population-based, pediatric sample: a genetic association study

BACKGROUND

Serotonin system genes are commonly studied in obsessive-compulsive disorder (OCD), but genetic studies to date have produced inconsistent results, possibly because phenotypic heterogeneity has not been adequately accounted for. In this paper, we studied candidate serotonergic genes and homogenous phenotypic subgroups as presented through obsessive-compulsive (OC) trait dimensions in a general population of children and adolescents. We hypothesized that different serotonergic gene variants are associated with different OC trait dimensions and, furthermore, that they vary by sex.

METHODS

Obsessive-compulsive trait dimensions (Cleaning/Contamination, Counting/Checking, Symmetry/Ordering, Superstition, Rumination, and Hoarding) were examined in a total of 5,213 pediatric participants in the community using the Toronto Obsessive-Compulsive Scale (TOCS). We genotyped candidate serotonin genes (directly genotyping the 5-HTTLPR polymorphism in SLC6A4 for 2018 individuals and using single nucleotide polymorphism (SNP) array data for genes SLC6A4, HTR2A, and HTR1B for 4711 individuals). We assessed the association between variants across these genes and each of the OC trait dimensions, within males and females separately. We analyzed OC traits as both (a) dichotomized based on a threshold value and (b) quantitative scores.

RESULTS

The [L_G + S] variant in 5-HTTLPR was significantly associated with hoarding in males (p-value of 0.003 and 0.004 for categorical and continuous analyses, respectively). There were no significant findings for 5-HTTLPR in females. Using SNP array data, there were significant findings for rumination in males for HTR2A SNPs (p-value of 1.04e-6 to 5.20e-6).

CONCLUSIONS

This represents the first genetic association study of OC trait dimensions in a community-based pediatric sample. Our strongest results indicate that hoarding and rumination may be distinct in their association with serotonin gene variants and that serotonin gene variation may be specific to sex. Future genetic association studies in OCD should properly account for heterogeneity, using homogenous subgroups stratified by symptom dimension, sex, and age group.

Recent Advances in Research on Hoarding

PURPOSE OF REVIEW

The purpose of the following paper is to review recent literature trends and findings in hoarding disorder (HD). Our goal is to highlight recent research on etiology, associated features, and empirically based treatments.

RECENT FINDINGS

Recent literature has added support for cognitive differences as a risk factor for HD; however, there is evidence that individuals with HD may overestimate their level of cognitive impairment. Several associated features have been highlighted in recent studies, including emotion regulation, intolerance of uncertainty and distress intolerance, and attachment. Finally, several psychotherapeutic treatments for hoarding have been recently validated, including group-based therapy and treatments using the cognitive-behavioral model. Although recent research demonstrates that hoarding can be effectively treated with available psychotherapeutic modalities, the effectiveness of current treatments is not as robust as that for other psychiatric disorders and more work is needed in treatment precision.

Hoarding: A meta-analysis of age of onset

Hoarding disorder is present in 2-6% of the population and can have an immense impact on the lives of patients and their families. Before its inclusion the Diagnostic and Statistical Manual of Mental Disorders, 5th edition, pathological hoarding was often characterized as a symptom of obsessive-compulsive disorder, and several different diagnostic assessment methods were used to identify and characterize it. Although the age of onset of pathological hoarding is an important epidemiological measure, as clarifying the age of onset of hoarding symptoms may allow for early identification and implementation of evidence-based treatments before symptoms become clinically significant, the typical age of onset of hoarding is still uncertain. To that end, this study is a systematic review and meta-analysis of research published in English between the years 1900 and 2016 containing information on age of onset of hoarding symptoms. Twenty-five studies met inclusion criteria. The mean age of onset of hoarding symptoms across studies was 16.7 years old, with evidence of a bimodal distribution of onset. The authors conclude by discussing practice implications for early identification and treatment.

Presentation and Correlates of Hoarding Behaviors in Children with Autism Spectrum Disorders and Comorbid Anxiety or Obsessive-Compulsive Symptoms

We investigated the presentation and correlates of hoarding behaviors in 204 children aged 7-13 with autism spectrum disorder (ASD) and comorbid anxiety or obsessive-compulsive disorder (OCD) symptoms. Approximately 34% of the sample presented at least moderate levels, and with 7% presenting severe to extreme levels of hoarding. Child gender predicted hoarding severity. In addition, child ASD-related social difficulties together with attention-deficit and hyperactivity disorder symptom severity positively predicted hoarding controlling for child gender and restricted and repetitive behaviors. Finally, child anxiety/OCD symptoms positively predicted hoarding, controlling for all other factors. These results suggest hoarding behaviors may constitute a common feature of pediatric ASD with comorbid anxiety/OCD, particularly in girls and children with greater social difficulties and comorbid psychiatric symptom severity.

An Examination of the Role of Psychological Inflexibility in Hoarding Using Multiple Mediator Models

Hoarding is associated with functional impairment and impacts quality of life. One process that has been theorized to explain how hoarding develops and leads to impairment is psychological inflexibility, in which behavior is rigidly controlled by a perceived need to regulate internal experiences, at the expense of more effective, valued actions. The present study aimed to test the mediational role of psychological inflexibility in the development of hoarding and its impact on life satisfaction with a sample of 489 college students completing an online survey. Results indicated that multiple measures of psychological inflexibility (overall inflexibility, inattention, and values obstruction) mediated the relationship between distress and hoarding. Other measures of psychological inflexibility (overall inflexibility, cognitive fusion, and lack of values progress) mediated the link between hoarding severity and life satisfaction. These findings suggest that how one responds to distress and hoarding symptoms can influence symptom severity and life satisfaction, and that psychological flexibility may promote more adaptive outcomes. Thus, current interventions for problematic hoarding may be strengthened by targeting psychological inflexibility and related processes.

Heritability of hoarding symptoms across adolescence and young adulthood: A longitudinal twin study

Background

Twin studies of hoarding symptoms indicate low to moderate heritability during adolescence and considerably higher heritability in older samples, suggesting dynamic developmental etiological effects. The aim of the current study was to estimate the relative contribution of additive genetic and environmental effects to hoarding symptoms during adolescence and young adulthood and to estimate the sources of stability and change of hoarding symptoms during adolescence.

Methods

Univariate model-fitting was conducted in three cohorts of twins aged 15 (n = 7,905), 18 (n = 2,495) and 20–28 (n = 6,218). Longitudinal analyses were conducted in a subsample of twins for which data on hoarding symptoms was available at both age 15 and 18 (n = 1,701).

Results

Heritability estimates for hoarding symptoms at ages 15, 18 and 20–28 were 41% (95% confidence interval [CI]: 36–45%), 31% (95% CI: 22–39%) and 29% (95% CI: 24–34%) respectively. Quantitative sex-differences emerged in twins aged 15 at which point the heritability in boys was 33% (95% CI: 22–41%) and 17% (95% CI: 0–36%) in girls. Shared environmental effects played a negligible role across all samples with the exception of girls aged 15 where they accounted for a significant proportion of the variance (22%; 95% CI 6–36%). The longitudinal bivariate analyses revealed a significant phenotypic correlation of hoarding symptoms between ages 15 and 18 (0.40; 95% CI: 0.36–0.44) and a strong but imperfect genetic correlation (0.75; 95% CI: 0.57–0.94). The bivariate heritability was estimated to 65% (95% CI: 50–79%).

Conclusions

Hoarding symptoms are heritable from adolescence throughout young adulthood, although heritability appears to slightly decrease over time. Shared environmental effects contribute to hoarding symptoms only in girls at age 15. The stability of hoarding symptoms between ages 15 and 18 is largely explained by genetic factors, while non-shared environmental factors primarily have a time-specific effect. The findings indicate that dynamic developmental etiological effects may be operating across the life span.

Cognitive-Behavioral Treatment of Hoarding in Youth: A Case Illustration

Hoarding in children is associated with more severe ancillary psychopathology, and has poor treatment outcome. At present, there are no empirically established procedures for treating hoarding in youth. The present case illustration is of a 10-year old child ("Grace") who presented for treatment with significant hoarding related to academic concerns and additional unrelated symptoms of obsessive-compulsive disorder (OCD). Grace was treated with cognitive behavior therapy (CBT) primarily comprising exposure with response prevention, behavioral experiments, and cognitive therapy, along with a program of reinforcement delivered by her parents to maintain her motivation for therapy. After 23 sessions and one booster session, Grace's symptoms improved significantly, with gains maintained at 1-year follow-up. In addition to the benefits of the specific interventions chosen, the role of therapist-patient/parent alliance as a contributory factor for good outcome is emphasized. As hoarding is underinvestigated in youth, suggestions for further investigation are offered.