Assortative mating and parental genetic relatedness contribute to the pathogenicity of variably expressive variants.

We examined more than 97,000 families from four neurodevelopmental disease cohorts and the UK Biobank to identify phenotypic and genetic patterns in parents contributing to neurodevelopmental disease risk in children. We identified within- and cross-disorder correlations between six phenotypes in parents and children, such as obsessive-compulsive disorder (R = 0.32-0.38, p < 10-126). We also found that measures of sub-clinical autism features in parents are associated with several autism severity measures in children, including biparental mean Social Responsiveness Scale scores and proband Repetitive Behaviors Scale scores (regression coefficient = 0.14, p = 3.38 × 10-4). We further describe patterns of phenotypic similarity between spouses, where spouses show correlations for six neurological and psychiatric phenotypes, including a within-disorder correlation for depression (R = 0.24-0.68, p < 0.001) and a cross-disorder correlation between anxiety and bipolar disorder (R = 0.09-0.22, p < 10-92). Using a simulated population, we also found that assortative mating can lead to increases in disease liability over generations and the appearance of "genetic anticipation" in families carrying rare variants. We identified several families in a neurodevelopmental disease cohort where the proband inherited multiple rare variants in disease-associated genes from each of their affected parents. We further identified parental relatedness as a risk factor for neurodevelopmental disorders through its inverse relationship with variant pathogenicity and propose that parental relatedness modulates disease risk by increasing genome-wide homozygosity in children (R = 0.05-0.26, p < 0.05). Our results highlight the utility of assessing parent phenotypes and genotypes toward predicting features in children who carry rare variably expressive variants and implicate assortative mating as a risk factor for increased disease severity in these families.

The Association Between Heterosexual anal Intercourse and HIV Acquisition in Three Prospective Cohorts of Women.

The extent to which receptive anal intercourse (RAI) increases the HIV acquisition risk of women compared to receptive vaginal intercourse (RVI) is poorly understood. We evaluated RAI practice over time and its association with HIV incidence during three prospective HIV cohorts of women: RV217, MTN-003 (VOICE), and HVTN 907. At baseline, 16% (RV 217), 18% (VOICE) of women reported RAI in the past 3 months and 27% (HVTN 907) in the past 6 months, with RAI declining during follow-up by around 3-fold. HIV incidence in the three cohorts was positively associated with reporting RAI at baseline, albeit not always significantly. The adjusted hazard rate ratios for potential confounders (aHR) were 1.1 (95% Confidence interval: 0.8-1.5) for VOICE and 3.3 (1.6-6.8) for RV 217, whereas the ratio of cumulative HIV incidence by RAI practice was 1.9 (0.6-6.0) for HVTN 907. For VOICE, the estimated magnitude of association increased slightly when using a time-varying RAI exposure definition (aHR = 1.2; 0.9-1.6), and for women reporting RAI at every follow-up survey (aHR = 2.0 (1.3-3.1)), though not for women reporting higher RAI frequency (> 30% acts being RAI vs. no RAI in the past 3 months; aHR = 0.7 (0.4-1.1)). Findings indicated precise estimation of the RAI/HIV association, following multiple RVI/RAI exposures, is sensitive to RAI exposure definition, which remain imperfectly measured. Information on RAI practices, RAI/RVI frequency, and condom use should be more systematically and precisely recorded and reported in studies looking at sexual behaviors and HIV seroconversions; standardized measures would aid comparability across geographies and over time.

Assortative mating and parental genetic relatedness drive the pathogenicity of variably expressive variants.

We examined more than 38,000 spouse pairs from four neurodevelopmental disease cohorts and the UK Biobank to identify phenotypic and genetic patterns in parents associated with neurodevelopmental disease risk in children. We identified correlations between six phenotypes in parents and children, including correlations of clinical diagnoses such as obsessive-compulsive disorder (R=0.31-0.49, p<0.001), and two measures of sub-clinical autism features in parents affecting several autism severity measures in children, such as bi-parental mean Social Responsiveness Scale (SRS) scores affecting proband SRS scores (regression coefficient=0.11, p=0.003). We further describe patterns of phenotypic and genetic similarity between spouses, where spouses show both within- and cross-disorder correlations for seven neurological and psychiatric phenotypes, including a within-disorder correlation for depression (R=0.25-0.72, p<0.001) and a cross-disorder correlation between schizophrenia and personality disorder (R=0.20-0.57, p<0.001). Further, these spouses with similar phenotypes were significantly correlated for rare variant burden (R=0.07-0.57, p<0.0001). We propose that assortative mating on these features may drive the increases in genetic risk over generations and the appearance of "genetic anticipation" associated with many variably expressive variants. We further identified parental relatedness as a risk factor for neurodevelopmental disorders through its inverse correlations with burden and pathogenicity of rare variants and propose that parental relatedness drives disease risk by increasing genome-wide homozygosity in children (R=0.09-0.30, p<0.001). Our results highlight the utility of assessing parent phenotypes and genotypes in predicting features in children carrying variably expressive variants and counseling families carrying these variants.

One versus two biological parents with mental disorders: Relationship to educational attainment in the next generation.

BACKGROUND: Both maternal and, separately, paternal mental illness are associated with diminished academic attainment among children. However, the differential impacts of diagnostic type and degree of parental burden (e.g. one v. both parents affected) on these functional outcomes are unknown. METHODS: Using the Swedish national patient (NPR) and multi-generation (MGR) registers, 2 226 451 children (1 290 157 parental pairs), born 1 January 1973-31 December 1997, were followed through 31 December 2013. Diagnostic status of all cohort members was defined for eleven psychiatric disorders, and families classed by exposure: (1) parents affected with any disorder, (2) parents affected with a disorder group (e.g. neuropsychiatric disorders), and (3) parents affected with a specific disorder (e.g. ADHD). Pairs were further defined as 'unaffected,' 'single-affected,', or 'dual-affected.' Among offspring, the study evaluated fulfillment of four academic milestones, from compulsory (primary) school through University (college). Sensitivity analyses considered the impact of child's own mental health, as well as parental education, on main effects. RESULTS: Marked reductions in the odds of achievement were observed, emerging at the earliest levels of schooling for both single-affected [adjusted odds ratio (aOR), 0.50; 95% CI 0.49-0.51] and dual-affected (aOR 0.29, 95% CI 0.28-0.30) pairs and persisting thereafter [aOR range (single), 0.52-0.65; aOR range (dual), 0.30-0.40]. This pattern was repeated for analyses within diagnosis/diagnostic group. Main results were robust to adjustment for offspring mental health and parent education level. CONCLUSIONS: Parental mental illness is associated with profound reductions in educational attainment in the subsequent generation, with children from dual-affected families at uniquely high risk.

A 6-year retrospective review of psychiatric emergency service utilization by school-age children.

To explore utilization patterns and associated clinical factors of school-age children who present to a psychiatric emergency department. This was a 6-year retrospective chart review study of children 5-12 years of age who presented to a psychiatric emergency service from July 2012 to June 2018 (n = 1654 patients). Demographic variables, clinical diagnoses, lifetime adverse events (physical abuse, sexual abuse, and bullying), and history of self-harm were documented for each visit. We performed a chi square analysis to identify association between demographic and clinical features with key outcomes. Increased service utilization as defined by inpatient psychiatric admission, recurrent visits, or increased length of stay were found in patients who were adopted, presented with suicidal ideation or self-harm behaviors, had a history of abuse, and had a diagnosis of depression or autism. Trends over the course of the study indicated a significantly increased percentage of patients presenting with suicidal ideation, bullying, and self-harm behaviors. The data add to the limited literature regarding school-age children with a psychiatric emergency. Increased emergency service utilization for certain subgroups of children and trends over the course of the study underscore the need for enhanced treatment options for individuals with certain demographic or clinical features, and increased outpatient, intermediate, and inpatient treatment options, as well as preventative care.

Elevated common variant genetic risk for tourette syndrome in a densely-affected pedigree.

Tourette syndrome (TS) is a highly heritable neuropsychiatric disorder with complex patterns of genetic inheritance. Recent genetic findings in TS have highlighted both numerous common variants with small effects and a few rare variants with moderate or large effects. Here we searched for genetic causes of TS in a large, densely-affected British pedigree using a systematic genomic approach. This pedigree spans six generations and includes 122 members, 85 of whom were individually interviewed, and 53 of whom were diagnosed as "cases" (consisting of 28 with definite or probable TS, 20 with chronic multiple tics [CMT], and five with obsessive-compulsive behaviors [OCB]). A total of 66 DNA samples were available (25 TS, 15 CMT, 4 OCB cases, and 22 unaffecteds) and all were genotyped using a dense single nucleotide polymorphism (SNP) array to identify shared segments, copy number variants (CNVs), and to calculate genetic risk scores. Eight cases were also whole genome sequenced to test whether any rare variants were shared identical by descent. While we did not identify any notable CNVs, single nucleotide variants, indels or repeat expansions of near-Mendelian effect, the most distinctive feature of this family proved to be an unusually high load of common risk alleles for TS. We found that cases within this family carried a higher load of TS common variant risk similar to that previously found in unrelated TS cases. Thus far, the strongest evidence from genetic data for contribution to TS risk in this family comes from multiple common risk variants rather than one or a few variants of strong effect.

Receptive anal sex contributes substantially to heterosexually acquired HIV infections among at-risk women in twenty US cities: Results from a modelling analysis.

PROBLEM: Receptive anal intercourse (RAI) is more efficient than receptive vaginal intercourse (RVI) at transmitting HIV, but its contribution to heterosexually acquired HIV infections among at-risk women in the USA is unclear. METHOD OF STUDY: We analysed sexual behaviour data from surveys of 9152 low-income heterosexual women living in 20 cities with high rates of HIV conducted in 2010 and 2013 as part of US National HIV Behavioral Surveillance. We estimated RAI prevalence (past-year RAI) and RAI fraction (fraction of all sex acts (RVI and RAI) at the last sexual episode that were RAI among those reporting past-year RAI) overall and by key demographic characteristics. These results and HIV incidence were used to calibrate a risk equation model to estimate the population attributable fraction of new HIV infections due to RAI (PAFRAI ) accounting for uncertainty in parameter assumptions. RESULTS: Receptive anal intercourse prevalence (overall: 32%, city range: 19%-60%) and RAI fraction (overall: 27%, city range: 18%-34%) were high overall and across cities, and positively associated with exchange sex. RAI accounted for an estimated 41% (uncertainty range: 18%-55%) of new infections overall (city range: 21%-57%). Variability in PAFRAI estimates was most influenced by uncertainty in the estimate of the per-act increased risk of RAI relative to RVI and the number of sex acts. CONCLUSION: Receptive anal intercourse may contribute disproportionately to new heterosexually acquired HIV infections among at-risk low-income women in the USA, meaning that tools to prevent HIV transmission during RAI are warranted. The number of RVI and RAI acts should also be collected to monitor heterosexually acquired HIV infections.

Evaluating the Impact of Nonrandom Mating: Psychiatric Outcomes Among the Offspring of Pairs Diagnosed With Schizophrenia and Bipolar Disorder.

BACKGROUND: Nonrandom mating has been shown for psychiatric diagnoses, with hypothesized-but not quantified-implications for offspring liability. This national cohort study enumerated the incidence of major psychiatric disorders among the offspring of parent pairs affected with schizophrenia (SCZ) and/or bipolar disorder (BIP) (i.e., dual-affected pairs). METHODS: Participants were all Swedish residents alive or born between 1968 and 2013 (n = 4,255,196 unique pairs and 8,343,951 offspring). Offspring with dual-affected, single-affected, and unaffected parents were followed (1973-2013) for incidence of broad psychiatric disorders. Primary outcomes included hazard ratio (HR) and cumulative incidence for SCZ and BIP in the offspring. Additional outcomes included any neuropsychiatric, anxiety, depressive, personality, or substance use disorders. Cumulative incidences of SCZ and BIP were used to inform heritability models for these disorders. RESULTS: Hazards were highest within disorder (e.g., offspring of dual-SCZ pairs had sharply raised hazards for SCZ [HR = 55.3]); however, they were significantly raised for all diagnoses (HR range = 2.89-11.84). Incidences were significantly higher for the majority of outcomes, with 43.4% to 48.5% diagnosed with "any" disorder over follow-up. Risks were retained, with modest attenuations, for the offspring of heterotypic pairs. The estimated heritability of liability for SCZ (h2 = 0.62, 95% confidence interval = 0.55-0.70) and BIP (h2 = 0.52, 95% confidence interval = 0.46-0.58) did not differ significantly from estimates derived from single-affected parents. CONCLUSIONS: Risks for a broad spectrum of psychiatric diagnoses are significantly raised in the offspring of dual-affected parents, in line with expectations from a polygenic model of liability to disease risk. How these risks may contribute to population maintenance of these disorders is considered.

A transcultural study of hoarding disorder: Insights from the United Kingdom, Spain, Japan, and Brazil.

Though problematic hoarding is believed to be a universal human behavior, investigations of clinically-defined hoarding disorder (HD) have been confined almost exclusively to Western countries. The current investigation sought to describe and directly compare the features of individuals meeting diagnostic criteria for HD across four distinct cultural settings. Participants were 82 individuals meeting DSM-5 diagnostic criteria for HD, recruited and assessed by trained clinicians at one of four project sites: London, Barcelona, Fukuoka, and Rio de Janeiro. A series of semi-structured interviews and self-report scales were administered, including assessments of socio-demographic characteristics, psychiatric comorbidity, and severity of hoarding and related features. Results indicate that the severity and core features of HD, as well as the cognitions and behaviors commonly associated with this condition, are largely stable across cultures. However, some differences in patient demographics-in particular age, marital status, and clinical expression-as well as comorbid psychiatric features also emerged. These findings confirm that HD, as defined in DSM-5, exists and presents with similar phenomenology across the studied cultures. Future, more fine-grained, research will be needed to study the features of the disorder in additional cultures (e.g., non-industrialized nations) and to evaluate the impact of these cultural aspects on the design of interventions for the disorder.

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.

Pharmacoepidemiology of obsessive-compulsive disorder: A Swedish nationwide cohort study.

The extent to which clinicians adhere to international guidelines for the pharmacological management of obsessive-compulsive disorder (OCD) is unknown. We aimed to comprehensively map the patterns of prescription of psychotropic drugs for OCD patients (adults and children) at the Swedish national level and to compare these prescription patterns to best-practice recommendations in international guidelines. We linked the Swedish National Patient Register and the Swedish Prescribed Drug Register, which includes a record for all medications prescribed and dispensed in Sweden since July 2005. Of all active OCD cases in the Swedish National Patient Register between July 1st, 2005, and December 31st 2008 (N=10,523), 85% received at least one psychotropic drug. Most of the medicated adults and children with OCD (88%) received serotonin reuptake inhibitors (SRIs). Of all adults and children prescribed SRIs, 16% received sub-optimal doses. An additional 12% of all medicated patients were prescribed drugs that never included an SRI. Approximately 75% of the patients on SRIs received additional drugs (67% anxiolytics/hypnotics, 27% antipsychotics, 17% serotonin and norepinephrine reuptake inhibitors, 24% other antidepressants). Twelve percent of all medicated patients were at least 'regular' users, and 3% 'heavy' users of benzodiazepines. We also observed important variations in prescription practices according to patient's gender, age, and comorbidity status. We conclude that a substantial number of OCD patients might benefit from changes in their prescriptions. Dissemination of best-practice prescription guidelines for OCD is a major educational goal for the future. Monitoring of these prescription patterns over time is warranted.

Patterns of Nonrandom Mating Within and Across 11 Major Psychiatric Disorders.

IMPORTANCE: Psychiatric disorders are heritable, polygenic traits, which often share risk alleles and for which nonrandom mating has been suggested. However, despite the potential etiological implications, the scale of nonrandom mating within and across major psychiatric conditions remains unclear. OBJECTIVE: To quantify the nature and extent of nonrandom mating within and across a broad range of psychiatric conditions at the population level. DESIGN, SETTING, AND PARTICIPANTS: Population-based cohort using Swedish population registers. Participants were all Swedish residents with a psychiatric diagnosis of interest (attention-deficit/hyperactivity disorder, autism spectrum disorder, schizophrenia, bipolar disorder, major depression, generalized anxiety disorder, agoraphobia, social phobia, obsessive-compulsive disorder, anorexia, or substance abuse), along with their mates. Individuals with select nonpsychiatric disorders (Crohn's disease, type 1 and type 2 diabetes mellitus, multiple sclerosis, or rheumatoid arthritis) were included for comparison. General population samples were also derived and matched 1:5 with each case proband. Inpatient and outpatient diagnostic data were derived from the Swedish National Patient Register (1973-2009), with analyses conducted between June 2014 and May 2015. MAIN OUTCOMES AND MEASURES: Correlation in the diagnostic status of mates both within and across disorders. Conditional logistic regression was used to quantify the odds of each diagnosis in the mates of cases relative to matched population controls. RESULTS: Across cohorts, data corresponded to 707 263 unique case individuals, with women constituting 45.7% of the full population. Positive correlations in diagnostic status were evident between mates. Within-disorder correlations were marginally higher (range, 0.11-0.48) than cross-disorder correlations (range, 0.01-0.42). Relative to matched populations, the odds of psychiatric case probands having an affected mate were significantly elevated. Differences in the magnitude of observed relationships were apparent by disorder (odds ratio range, 0.8-11.4). The number of comorbidities in a case proband was associated with the proportion of affected mates. These relationships were not apparent or weaker in magnitude among nonpsychiatric conditions (correlation range, -0.03 to 0.17). CONCLUSIONS AND RELEVANCE: Nonrandom mating is evident in psychiatric populations both within specific disorders and across the spectrum of psychiatric conditions. This phenomenon may hold important implications for how we understand the familial transmission of these disorders and for psychiatric genetic research.

Caregiver burden, family accommodation, health, and well-being in relatives of individuals with hoarding disorder.

BACKGROUND: Hoarding Disorder (HD), a new diagnostic entity in DSM-5, is associated with substantial functional impairment and family frustration but data from well-characterized samples is lacking. METHOD: Participants were 37 individuals meeting DSM-5 criteria for HD, 55 relatives of individuals meeting criteria for HD, and comparison groups of 51 self-identified collectors and 25 relatives of collectors. All participants completed a clinician-administered diagnostic interview for HD and an online battery of standardized measures of health, well-being, and impairment. RESULTS: Substantial functional impairment was found for both HD individuals and their relatives. HD relatives reported significantly greater carer burden and accommodation of hoarding behaviors than relatives of collectors. Perceived level of squalor, co-habiting with, and increasing age of the HD individual were significant predictors of carer burden and functional impairment in the relatives. LIMITATIONS: The use of self-identified HD individuals may have produced a bias towards participants with relatively good insight. Subjective biases in self-reported symptoms cannot be ruled out, although the use of informant-report data provided some independent validation. CONCLUSIONS: HD is associated with substantial functional impairment for both sufferers and their relatives. The level of carer burden experienced by HD relatives was comparable to or greater than that reported in the literature by relatives of individuals with dementia. The findings indicate that relatives of individuals with HD may benefit from increased support and suggest that it may be beneficial to involve family members in the treatment of HD.

Epidemiology of hoarding disorder.

BACKGROUND: Hoarding disorder is typified by persistent difficulties discarding possessions, resulting in significant clutter that obstructs the individual's living environment and produces considerable functional impairment. The prevalence of hoarding disorder, as defined in DSM-5, is currently unknown. AIMS: To provide a prevalence estimate specific to DSM-5 hoarding disorder and to delineate the demographic, behavioural and health features that characterise individuals with the disorder. METHOD: We conducted a two-wave epidemiological study of 1698 adult individuals, originally recruited via the South East London Community Health (SELCoH) study. Participants screening positively for hoarding difficulties in wave 1, and who agreed to be re-contacted for wave 2 (n = 99), underwent in-home psychiatric interviews and completed a battery of self-report questionnaires. Current DSM-5 diagnoses were made via consensus diagnostic procedure. RESULTS: In total, 19 individuals met DSM-5 criteria for hoarding disorder at the time of interview, corresponding to a weighted prevalence of 1.5% (95% CI 0.7-2.2). Those with hoarding disorder were older and more often unmarried (67%). Members of this group were also more likely to be impaired by a current physical health condition (52.6%) or comorbid mental disorder (58%), and to claim benefits as a result of these issues (47.4%). Individuals with hoarding disorder were also more likely to report lifetime use of mental health services, although access in the past year was less frequent. CONCLUSIONS: With a lower-bound prevalence of approximately 1.5%, hoarding disorder presents as a condition that affects people of both genders and is associated with substantial adversity.

Overlap and specificity of genetic and environmental influences on excessive acquisition and difficulties discarding possessions: Implications for hoarding disorder.

A reluctance to discard items, leading to severely cluttered living spaces, is the landmark feature of hoarding disorder (HD). Many, but not all, individuals with HD also excessively acquire, buy or even steal items that they do not need and for which no space is available. In DSM-5, "excessive acquisition" can be coded as a specifier of HD. Despite their consistent co-occurrence, the question of whether excessive acquisition and difficulties discarding possessions share a common etiology remains unanswered. The current study sought to flesh out this relationship by examining the extent of shared genetic and environmental influences on the association between excessive acquisition and difficulties discarding in a community sample of adult, female twins. A total of 5,022 female twins (2,529 pairs; mean age = 55.5 years) completed a self-report measure of hoarding symptoms, including items assessing excessive acquisition and difficulties discarding. The data were analyzed using bivariate twin modeling methods in the statistical program Mx. As expected, we found a strong phenotypic correlation (0.63) between excessive acquisition and difficulty discarding items. Both traits were moderately heritable. The genetic correlation between the traits was estimated to be 0.77 (95% CI: 0.69-0.85), indicating a substantial but imperfect genetic overlap. The non-shared environmental correlation (0.50 [95% CI: 0.42-0.57]), though lower, was also significant. The findings demonstrate a substantial genetic, and more modest environmental, etiological overlap between the excessive acquisition of possessions and difficulties discarding them, providing a possible explanation for their frequent co-occurrence in HD. However, given that the etiological overlap is not perfect, unique etiological influences, particularly environmental, on each phenotype seem plausible.

Photograph-aided assessment of clutter in hoarding disorder: is a picture worth a thousand words?

BACKGROUND: Clutter impeding the normal use of living spaces is a landmark feature of hoarding disorder (HD) but can also be present in other conditions. The assessment of clutter ideally requires home visits, although such assessments are sometimes not feasible. This study examined whether photographs from patients' homes can assist in the diagnostic process. METHODS: Thirty-two professionals with experience with hoarding cases were shown pictures from the inside of 10 houses and asked to decide whether the house belonged to a person with HD, a person with obsessive compulsive disorder (OCD), or a healthy collector. Participants also rated different features of the room appearing in each picture (overall amount of possessions, tidiness, functionality, number of different classes of items, and cleanliness). RESULTS: Sensitivity for the HD and collectors' pictures was high, whereas sensitivity for the OCD pictures was substantially lower. Specificity was high for all groups. Rooms belonging to HD individuals were rated as significantly more cluttered, more untidy, less functional, containing a higher number of different classes of items, and being less clean than the rooms from the remaining groups. CONCLUSIONS: Photographs may be used to assist clinicians in determining the presence of clinically significant levels of clutter in the event a home visit is not feasible. Although differential diagnosis will usually not be possible from photographs alone, examination of certain characteristics of the environment might provide useful diagnostic clues. Combined with a thorough psychopathological interview, the use of photographs may increase the clinician's confidence in the diagnosis of HD.

Finders keepers: the features differentiating hoarding disorder from normative collecting.

OBJECTIVE: A new diagnostic category called Hoarding Disorder (HD) has been proposed for inclusion in DSM-5. It is paramount that this addition does not result in an over-pathologization of normative behavior. Collectors constitute a valid population within which to test the diagnostic boundaries of HD. The current study explored the features that differentiate pathological hoarding from normative collecting. METHODS: Participants were 29 individuals with a diagnosis of HD and 20 individuals who self-identified as collectors who enrolled in the London Field Trial for HD. A series of semi-structured interviews (often in the participants' homes) were conducted, including a detailed assessment of the typical elements of the collecting process. Participants also completed a battery of self-report questionnaires. RESULTS: Collectors were more likely than those with HD to be male, partnered, and free of psychiatric conditions or medication. Like those with HD, collectors reported the acquisition of, attachment to, and reluctance to discarding objects. However, the resulting clutter and impairment were minimal in this group and ultimately insufficient to garner an HD diagnosis. Collectors were, additionally, more focused in their acquisitions (e.g., confining their accumulations to a narrow range of items), more selective (e.g., planning and purchasing only pre-determined items), more likely to organize their possessions and less likely to accumulate in an excessive manner. CONCLUSIONS: There are important quantitative and qualitative differences between HD and normative collecting. For this reason, collectors are unlikely to be inappropriately pathologized by the introduction of HD.

Hoarding versus collecting: where does pathology diverge from play?

A new diagnosis termed Hoarding Disorder has been proposed for inclusion in the upcoming DSM-5 to cover the majority of cases where severe hoarding occurs in the absence of, or independently from other mental disorders. Much effort has been directed to ensuring that the proposed criteria discriminate Hoarding Disorder from other mental disorders, particularly those historically associated with hoarding (e.g. OCD, OCPD). Considerably less attention, however, has been paid to addressing the suitability of the proposed criteria for effectively differentiating pathological hoarding from normative collecting behavior. This is crucial in order to avoid false positives or the overpathologization of this widespread human activity. Collecting behavior mirrors many of the core features of hoarding (e.g. the acquisition of and emotional attachment to a potentially large number of objects), is highly prevalent and is generally considered a normative form of object amassment; as such, it represents a valid population with which to explore the diagnostic boundaries of Hoarding Disorder. Examination of the collecting literature, within the context of the hoarding diagnostic criteria, indicates that, for the majority of collectors, a diagnosis of Hoarding Disorder is likely to be effectively ruled out. For a minority of 'extreme' collectors, a diagnosis may potentially be adequate. This review highlights the similarities and differences between hoarding and collecting and offers suggestions for further research in this group.