Ashley E. Nordsletten

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 (Crohns 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.

Towards an international expert consensus for defining treatment response, remission, recovery and relapse in obsessive-compulsive disorder.

Marked inconsistencies exist in how treatment response, remission, recovery and relapse are defined in clinical trials for obsessive‐compulsive disorder (OCD). This impairs the comparability of results and communication in the field. Empirical methods (e.g., signal detection analyses) have been used to calculate the optimal amount of symptom improvement to classify an individual as a “responder” or “remitter”, both in adults1, 2, 3, 4 and children5 with OCD. Unfortunately, this has led to different recommendations.

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.

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

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.

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.

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.

Ethnocultural Aspects of Hoarding Disorder

Hoarding Disorder (HD) is characterized by difficulty discarding and parting with possessions, resulting in the accumulation of belongings that congest and clutter active living areas and compromises their use. While HD is thought to be a universal phenomenon, the phenomenological, epidemiological, and clinical research studies published to date have mainly been conducted in Western, industrialized countries, precluding conclusions about the prevalence and phenomenological differences that may exist across cultures in the expression of HD. A systematic review of treatment studies in HD revealed that all have been carried out in the US and have included a large majority (about 90%) of White/Caucasian individuals, making it difficult to ascertain whether existing treatments are equally effective for minority groups. There is a need to consider HD from a transcultural perspective in order to understand the expression of this disorder across different cultures and ethnic groups. We highlight areas of priority for future studies to ensure that the conception of hoarding and its study is inclusive, sensitive, and informative.

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.

PHOTOGRAPH-AIDED ASSESSMENT OF CLUTTER IN HOARDING DISORDER: IS A PICTURE WORTH A THOUSAND WORDS?: Research Article: Photograph-Aided Assessment of Clutter in HD

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.

Photograph-aided assessment of clutter in hoarding disorder

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.