Familial co-aggregation of schizophrenia and eating disorders in Sweden and Denmark

Comorbidity of anorexia nervosa and schizophrenia: A systematic review

Research on the intersection between eating disorders and schizophrenia (SCZ) has mainly focused on binge eating, since increased appetite and metabolic side effects are common during antipsychotic use. However, the prevalence of restrictive eating and anorexia nervosa may be higher in people with SCZ than in the general population, and evidence suggests shared genetic liability for SCZ and anorexia nervosa (AN). The aim of this systematic review was to examine the prevalence, psychological and biological mechanisms, and theoretical underpinnings underlying the co-occurrence of AN and SCZ. We identified 40 articles that met inclusion criteria. Evidence suggested that the prevalence of AN in patients with SCZ is higher than would be expected in the general population; conversely, evidence regarding the prevalence of SCZ in AN was mixed. Psychological mechanisms underlying AN in people with SCZ fell into three categories: positive symptoms, negative symptoms, and atypical pathways. A limited literature generally supports the hypothesis of higher prevalence of AN in patients with SCZ, but there are few studies in this area. Studies of the prevalence of SCZ in AN yield more mixed findings, although these studies are also relatively small and few. Further, studies of both types tend to include only clinically ascertained samples, which limits the generalizability of findings beyond patients. Larger, better-designed studies may improve identification and treatment of people with co-occurring SCZ and AN.

Early intervention in eating disorders: introducing the chronopathogram

Eating disorders (EDs) pose significant challenges to mental and physical health, particularly among adolescents and young adults, with the COVID-19 pandemic exacerbating risk factors. Despite advancements in psychosocial and pharmacological treatments, improvements remain limited. Early intervention in EDs, inspired by the model developed for psychosis, emphasizes the importance of timely identification and treatment initiation to improve prognosis. Challenges in identifying prodromal phases and measuring the duration of untreated illness highlight the complexity of early intervention efforts in EDs. Current research focuses on reducing the duration of untreated eating disorder (DUED) and understanding the cognitive and behavioral symptoms preceding ED onset. However, current early intervention programs for EDs showed mixed results, necessitating further investigation. We introduce here the chronopathogram, a tool that may aid in precisely investigating the role of development in EDs. A chronopathogram is a graphical representation of pathological events as they unfold over time. Understanding the neurodevelopmental aspects of EDs and utilizing tools like the chronopathogram can aid in tracking the unfolding of symptoms over time, facilitating early detection and intervention efforts. Overall, addressing the key factors influencing the onset and course of EDs is essential for effective early intervention in these conditions.Level of evidence: Level V narrative review.

Shared Genetic Architecture Between Schizophrenia and Anorexia Nervosa: A Cross-trait Genome-Wide Analysis

BACKGROUND AND HYPOTHESIS

Schizophrenia (SCZ) and anorexia nervosa (AN) are 2 severe and highly heterogeneous disorders showing substantial familial co-aggregation. Genetic factors play a significant role in both disorders, but the shared genetic etiology between them is yet to be investigated.

STUDY DESIGN

Using summary statistics from recent large genome-wide association studies on SCZ (Ncases = 53 386) and AN (Ncases = 16 992), a 2-sample Mendelian randomization analysis was conducted to explore the causal relationship between SCZ and AN. MiXeR was employed to quantify their polygenic overlap. A conditional/conjunctional false discovery rate (condFDR/conjFDR) framework was adopted to identify loci jointly associated with both disorders. Functional annotation and enrichment analyses were performed on the shared loci.

STUDY RESULTS

We observed a cross-trait genetic enrichment, a suggestive bidirectional causal relationship, and a considerable polygenic overlap (Dice coefficient = 62.2%) between SCZ and AN. The proportion of variants with concordant effect directions among all shared variants was 69.9%. Leveraging overlapping genetic associations, we identified 6 novel loci for AN and 33 novel loci for SCZ at condFDR <0.01. At conjFDR <0.05, we identified 10 loci jointly associated with both disorders, implicating multiple genes highly expressed in the cerebellum and pituitary and involved in synapse organization. Particularly, high expression of the shared genes was observed in the hippocampus in adolescence and orbitofrontal cortex during infancy.

CONCLUSIONS

This study provides novel insights into the relationship between SCZ and AN by revealing a shared genetic component and offers a window into their complex etiology.

Body image as a mediator in the relationship between psychotic experiences and later disordered eating: A 12-month longitudinal study in high school adolescents

BACKGROUND

The relationship between psychosis and disordered eating remains a challenging area of research to which little interest was paid. Using longitudinal data, we aimed to explore the hypothesis that the pathways from psychotic experiences (PEs) to disordered eating (DE) and body-mass index (BMI) are mediated by body-image disturbances.

METHODS

A prospective longitudinal study was performed. High-school students (N = 510, 61.2% females, mean age of 16.05 ± 1.01 years) were asked to complete three scheduled assessments (Baseline, 6 months, and 12 months).

RESULTS

Two body image components, that is, Overweight Preoccupation and Body Area Satisfaction, mediated the prospective association between baseline PEs and DE 12 months later. Direct effects were significant. After accounting for indirect effects through more severe body image concerns at 6 months, higher baseline PEs were significantly associated with greater DE at 12 months. Baseline PEs and 6-month body image explained a significant proportion of variance in 12-month DE. However, we did not find evidence of a direct prospective association between PEs and BMI.

CONCLUSION

This study is the first to assess the mediating role of body image between PEs and DE. Findings offer promising new avenues for early intervention to help mitigate the effects of PEs on DE in adolescents.

The impact of genetic risk for schizophrenia on eating disorder clinical presentations

A growing body of literature recognizes associations between eating disorders (EDs) and schizophrenia and suggests that familial liability to schizophrenia in individuals with anorexia nervosa (AN) reveals distinct patterns of clinical outcomes. To further investigate the influence of schizophrenia genetic liability among individuals with EDs, we evaluated the associations between schizophrenia polygenic risk scores (PRS) and clinical presentations of individuals with EDs including their overall health condition and ED-related symptoms. Using data from two previous studies of the genetics of EDs comprising 3,573 Anorexia Nervosa Genetics Initiative (ANGI) cases and 696 Binge Eating Genetics Initiative (BEGIN) cases born after 1973 and linked to the Swedish National Patient Register, we examined the association of schizophrenia PRS on ED clinical features, psychiatric comorbidities, and somatic and mental health burden. Among ANGI cases, higher schizophrenia PRS was statistically significantly associated with higher risk of major depressive disorder (MDD) measured by hazard ratio (HR) with 95% confidence interval (CI) (HR [95% CI]: 1.07 [1.02, 1.13]) and substance abuse disorder (SUD) (HR [95% CI]: 1.14 [1.03, 1.25]) after applying multiple testing correction. Additionally, higher schizophrenia PRS was associated with decreased clinical impairment assessment scores (-0.56, 95% CI: [-1.04, -0.08]) at the conventional significance level (p < 0.05). Further, in BEGIN cases, higher schizophrenia PRS was statistically significantly associated with earlier age at first ED symptom (-0.35 year, 95% CI: [-0.64, -0.06]), higher ED symptom scores (0.16, 95% CI: [0.04, 0.29]), higher risk of MDD (HR [95% CI]: 1.18 [1.04, 1.34]) and SUD (HR [95% CI]: 1.36 [1.07, 1.73]). Similar, but attenuated, patterns held in the subgroup of exclusively AN vs other eating disorder (OED) cases. These results suggest a similar pattern of influence of schizophrenia PRS for AN and OED cases in terms of psychiatric comorbidities, but a different pattern in terms of ED-related clinical features. The disparity of the effect of schizophrenia PRS on AN vs OED merits further investigation.

The Nepean Belief Scale (NBS) as a tool to investigate the intensity of beliefs in anorexia nervosa: psychometric properties of the Italian version

BACKGROUND

People with anorexia nervosa (AN) show a peculiar impairment of insight regarding their condition, often manifesting a denial of extreme emaciation and sometimes hiding or underreporting socially undesirable abnormal eating patterns. Sometimes the intensity of the beliefs held by patients with AN reach a delusional intensity.

OBJECTIVES

In this study, the Italian version of the Nepean Belief Scale was applied to a sample of patients diagnosed with AN to investigate the intensity of their beliefs and convictions and its clinical correlates.

METHODS

The Nepean Belief Scale (NBS) was translated and adapted to Italian and applied to a sample of patients diagnosed with AN based on the Structured Clinical Interview for DSM-5 (SCID-5).

RESULTS

The Italian version of the 5-item NBS showed excellent reliability. Convergent validity was proved by negative association with levels of insight measured with the Schedule for the Assessment of Insight in Eating Disorders. Beliefs of delusional intensity were reported by 10% of participants. Those with a greater intensity of beliefs, either overvalued or delusional ideas, were more likely to report poorer general cognitive performances on the Montreal Cognitive Assessment. No association was observed between NBS score and age, body mass index, symptoms of eating disorders, body dissatisfaction, or levels of depression. Fear of weight gain and control seeking were the most often reported themes at the NBS.

CONCLUSIONS

The Italian version of the NBS is a reasonably reliable, valid, and usable tool for the multidimensional assessment of insight in AN. Level of evidence Level III, Evidence obtained from well-designed cohort or case-control analytic studies.

Genome-wide analysis of anorexia nervosa and major psychiatric disorders and related traits reveals genetic overlap and identifies novel risk loci for anorexia nervosa

Anorexia nervosa (AN) is a heritable eating disorder (50-60%) with an array of commonly comorbid psychiatric disorders and related traits. Although significant genetic correlations between AN and psychiatric disorders and related traits have been reported, their shared genetic architecture is largely understudied. We investigated the shared genetic architecture of AN and schizophrenia (SCZ), bipolar disorder (BIP), major depression (MD), mood instability (Mood), neuroticism (NEUR), and intelligence (INT). We applied the conditional false discovery rate (FDR) method to identify novel risk loci for AN, and conjunctional FDR to identify loci shared between AN and related phenotypes, to summarize statistics from relevant genome-wide association studies (GWAS). Individual GWAS samples varied from 72,517 to 420,879 participants. Using conditional FDR we identified 58 novel AN loci. Furthermore, we identified 38 unique loci shared between AN and major psychiatric disorders (SCZ, BIP, and MD) and 45 between AN and psychological traits (Mood, NEUR, and INT). In line with genetic correlations, the majority of shared loci showed concordant effect directions. Functional analyses revealed that the shared loci are involved in 65 unique pathways, several of which overlapped across analyses, including the "signal by MST1" pathway involved in Hippo signaling. In conclusion, we demonstrated genetic overlap between AN and major psychiatric disorders and related traits, and identified novel risk loci for AN by leveraging this overlap. Our results indicate that some shared characteristics between AN and related disorders and traits may have genetic underpinnings.

Risk factors for anorexia nervosa: A population-based investigation of sex differences in polygenic risk and early life exposures

OBJECTIVE

To examine sex differences in risk factors for anorexia nervosa (AN).

METHOD

This population-based study involved 44,743 individuals (6,239 AN cases including 5,818 females and 421 males, and 38,504 controls including 18,818 females and 19,686 males) born in Denmark between May 1981 and December 2009. Follow-up began on the individual's sixth birthday and ended at AN diagnosis, emigration, death, or December 31, 2016, whichever occurred first. Exposures included socioeconomic status (SES), pregnancy, birth, and early childhood factors based on data from Danish registers, and psychiatric and metabolic polygenic risk scores (PRS) based on genetic data. Hazard ratios were estimated using weighted Cox proportional hazards models stratified by sex (assigned at birth), with AN diagnosis as the outcome.

RESULTS

The effects of early life exposures and PRS on AN risk were comparable between females and males. Although we observed some differences in the magnitude and direction of effects, there were no significant interactions between sex and SES, pregnancy, birth, or early childhood exposures. The effects of most PRS on AN risk were highly similar between the sexes. We observed significant sex-specific effects of parental psychiatric history and body mass index PRS, though these effects did not survive corrections for multiple comparisons.

CONCLUSIONS

Risk factors for AN are comparable between females and males. Collaboration across countries with large registers is needed to further investigate sex-specific effects of genetic, biological, and environmental exposures on AN risk, including exposures in later childhood and adolescence as well as the additive effects of exposures.

PUBLIC SIGNIFICANCE

Sex differences in the prevalence and clinical presentation of AN warrant examination of sex-specific risk factors. This population-based study indicates that the effects of polygenic risk and early life exposures on AN risk are comparable between females and males. Collaboration between countries with large registers is needed to further investigate sex-specific AN risk factors and improve early identification of AN.

Association of family history of schizophrenia and clinical outcomes in individuals with eating disorders

BACKGROUND

Familial co-aggregation studies of eating disorders (EDs) and schizophrenia reveal shared genetic and environment factors, yet their etiological and clinical relationship remains unclear. We evaluate the influence of schizophrenia family history on clinical outcomes of EDs.

METHODS

We conducted a cohort evaluation of the association between family history of schizophrenia and ED clinical features, psychiatric comorbidities, and somatic and mental health burden in individuals born in Sweden 1977-2003 with anorexia nervosa (AN) or other EDs (OED: bulimia nervosa, binge-eating disorder, and ED not otherwise specified).

RESULTS

Of 12 424 individuals with AN and 20 716 individuals with OED, 599 (4.8%) and 1118 (5.4%), respectively, had a family history of schizophrenia (in up to third-degree relatives). Among individuals with AN, schizophrenia in first-degree relatives was significantly associated with increased comorbid attention-deficit/hyperactivity disorder (ADHD) [HR(95% CI) 2.26 (1.27-3.99)], substance abuse disorder (SUD) [HR (95% CI) 1.93 (1.25-2.98)], and anxiety disorders [HR (95% CI) 1.47 (1.08-2.01)], but higher lowest illness-associated body mass index (BMI) [1.14 kg/m², 95% CI (0.19-2.10)]. Schizophrenia in any relative (up to third-degree) in AN was significantly associated with higher somatic and mental health burden, but lower ED psychopathology scores [-0.29, 95% CI (-0.54 to -0.04)]. Schizophrenia in first-degree relatives in individuals with OED was significantly associated with increased comorbid ADHD, obsessive-compulsive disorder, SUD, anxiety disorders, somatic and mental health burden, and suicide attempts.

CONCLUSIONS

We observed different patterns of ED-related outcomes, psychiatric comorbidity, and illness burden in individuals with EDs with and without family histories of schizophrenia and provide new insights into the diverse manifestations of EDs.

Co-occurring psychotic and eating disorders in England: findings from the 2014 Adult Psychiatric Morbidity Survey

BACKGROUND

Psychotic disorders and eating disorders are complex mental illnesses associated with increased mortality and functional impairment. This study aimed to investigate the co-occurrence and relationships between eating disorders and psychotic disorders and assess the mediation effect of mood instability.

METHODS

This study used data from the Adult Psychiatric Morbidity Survey (APMS) 2014, a general population-based survey in England. Participants (total N = 7546, female N = 4488, male N = 3058, mean age = 52.3 years) were categorised based on psychotic disorder status into the groups of probable psychosis, diagnosed psychosis, and healthy controls without psychosis. The dependent variable of this study was the presence or absence of an eating disorder, with mood instability as the mediator. Logistic regression and mediation analyses were conducted to assess the relationships between these variables.

RESULTS

Both probable and diagnosed psychoses were significantly related to the presence of an eating disorder, and mood instability was found to be a mediating variable with moderate effect.

CONCLUSION

The present study demonstrates a significant relationship between eating disorders and psychotic disorders in the English general population, indicating higher levels of co-occurrence between these two groups of disorders than when compared with healthy controls. The findings also suggest the relationship between eating and psychotic disorders is mediated, to an extent, by the presence of mood instability traits. Future research could extend the present study's findings through assessing whether specific eating disorders are more significantly related to psychotic disorders than others.

Eating Disorders and Psychosis as Intertwined Dimensions of Disembodiment: A Narrative Review

Although psychosis is not one of the most commonly recognized psychiatric comorbidities of Eating Disorders (ED), there is an increasing empirical evidence of associations between these psychopathological conditions. Indeed, ED as well as early manifestations of schizophrenic psychosis emerge during developmental years and might present some affinities in the presentation at onset. For example, adolescents with anorexia nervosa (AN) may report psychotic-like eating-related symptoms such as delusional-like body image distortions and/or "anorexic voice". Conversely, early expressions of schizophrenia spectrum vulnerability might involve altered bodily experiences, delusional ideation on food and eating as well as pseudo-anorectic behaviors. From a phenomenological perspective, this partial symptomatic overlap may lie on common features of disturbed corporeality in terms of disembodiment, although these alterations of embodiment are presumably rooted in distinct pathogenetic pathways (e.g., primary childhood ontogenetic pathway in schizophrenia vs. a secondary adolescent ontogenetic pathway in AN). A clinical-phenomenological attitude could be important not only to better discern potential overlaps and affinities between the two conditions, but also to better conceptualize and treat those background alterations of the embodied self. In particular, a phenomenological exploration of the experiential side of eating-related behaviors could be a decisive step to support early differential diagnosis and treatment appropriateness.

Polygenic association with severity and long-term outcome in eating disorder cases

About 20% of individuals with anorexia nervosa (AN) remain chronically ill. Therefore, early identification of poor outcome could improve care. Genetic research has identified regions of the genome associated with AN. Patients with anorexia nervosa were identified via the Swedish eating disorder quality registers Stepwise and Riksät and invited to participate in the Anorexia Nervosa Genetics Initiative. First, we associated genetic information longitudinally with eating disorder severity indexed by scores on the Clinical Impairment Assessment (CIA) in 2843 patients with lifetime AN with or without diagnostic migration to other forms of eating disorders followed for up to 16 years (mean = 5.3 years). Second, we indexed the development of a severe and enduring eating disorder (SEED) by a high CIA score plus a follow-up time ≥5 years. We associated individual polygenic scores (PGSs) indexing polygenic liability for AN, schizophrenia, and body mass index (BMI) with severity and SEED. After multiple testing correction, only the BMI PGS when calculated with traditional clumping and p value thresholding was robustly associated with disorder severity (β_PGS = 1.30; 95% CI: 0.72, 1.88; p = 1.2 × 10^-5) across all p value thresholds at which we generated the PGS. However, using the alternative PGS calculation method PRS-CS yielded inconsistent results for all PGS. The positive association stands in contrast to the negative genetic correlation between BMI and AN. Larger discovery GWASs to calculate PGS will increase power, and it is essential to increase sample sizes of the AN GWASs to generate clinically meaningful PGS as adjunct risk prediction variables. Nevertheless, this study provides the first evidence of potential clinical utility of PGSs for eating disorders.

A comprehensive map of genetic relationships among diagnostic categories based on 48.6 million relative pairs from the Danish genealogy

The ability to extract multigenerational family relationships from large-scale population cohorts provides a powerful means to understand the heritability of a wide range of diseases and their genetic relationships to each other. By showing how the heritability of broad diagnostic categories changes over time and how said categories are related on the genetic level, our analysis of the Danish genealogy and linked national patient registers illustrates the vast potential of this resource in current biomedical research.

For more than half a century, Denmark has maintained population-wide demographic, health care, and socioeconomic registers that provide detailed information on the interaction between all residents and the extensive national social services system. We leverage this resource to reconstruct the genealogy of the entire nation based on all individuals legally residing in Denmark since 1968. We cross-reference 6,691,426 individuals with nationwide health care registers to estimate heritability and genetic correlations of 10 broad diagnostic categories involving all major organs and systems. Heritability estimates for mental disorders were consistently the highest across demographic cohorts (average h² = 0.406, 95% CI = [0.403, 0.408]), whereas estimates for cancers were the lowest (average h² = 0.130, 95% CI = [0.125, 0.134]). The average genetic correlation of each of the 10 diagnostic categories with the other nine was highest for gastrointestinal conditions (average r_g = 0.567, 95% CI = [0.566, 0.567]) and lowest for urogenital conditions (average r_g = 0.386, 95% CI = [0.385, 0.388]). Mental, pulmonary, gastrointestinal, and neurological conditions had similar genetic correlation profiles.

Modifiable factors associated with mental health symptoms in siblings of adolescents with anorexia nervosa

PURPOSE

Research demonstrates that anorexia nervosa (AN) takes a significant toll on affected families, yet the well-being of siblings has been largely overlooked. This study examines mental health symptoms in siblings of adolescents with AN and seeks to identify modifiable factors associated with well-being.

METHOD

Participants included 34 siblings (aged 11-19) of adolescents with AN and 47 age and sex matched controls. Participants and their caregivers completed assessments of anxiety, depression, internalizing and externalizing problems, and parentification. Siblings of adolescents with AN also completed the Sibling Perception Questionnaire, an assessment of perceptions and attitudes about AN.

RESULTS

Analyses indicated that siblings of adolescents with AN reported greater anxiety and parentification than controls. On caregiver reports of participants' internalizing and externalizing symptoms, no significant differences were found across groups. In siblings of adolescents with AN, females were more vulnerable to anxiety, depression, and negative attitudes and perceptions about AN than males. Perceived negative interpersonal interactions, specific to having a brother or sister with AN, were associated with greater anxiety and depression among AN siblings.

CONCLUSION

Findings from this pilot study suggest that siblings of adolescents with AN are vulnerable to anxiety and parentification behaviors. Negative interpersonal interactions specific to having a brother or sister with AN may perpetuate risk for poorer well-being. Caregivers may not be attuned to these struggles, highlighting the importance of provider and family education about sibling vulnerabilities. Therapeutic interventions that target siblings of adolescents with AN are also indicated.

LEVEL OF EVIDENCE

Level III, case-control analytic study.

Comorbidity between types of eating disorder and general medical conditions

BACKGROUND

Comorbidity with general medical conditions is common in individuals with eating disorders. Many previous studies do not evaluate types of eating disorder.

AIMS

To provide relative and absolute risks of bidirectional associations between (a) anorexia nervosa, bulimia nervosa and eating disorders not otherwise specified and (b) 12 general medical conditions.

METHOD

We included all people born in Denmark between 1977 and 2010. We collected information on eating disorders and considered the risk of subsequent medical conditions, using Cox proportional hazards regression. Absolute risks were calculated using competing risks survival analyses. We also considered risks for prior medical conditions and subsequent eating disorders.

RESULTS

An increased risk was seen for almost all disorder pairs (69 of 70). Hazard ratios for those with a prior eating disorder receiving a subsequent diagnosis of a medical condition ranged from 0.94 (95% CI 0.57-1.55) to 2.05 (95% CI 1.86-2.27). For those with a prior medical condition, hazard ratios for later eating disorders ranged from 1.35 (95% CI 1.26-1.45) to 1.98 (95% CI 1.71-2.28). Absolute risks for most later disorders were increased for persons with prior disorders, compared with reference groups.

CONCLUSIONS

This is the largest and most detailed examination of eating disorder-medical condition comorbidity. The findings indicate that medical condition comorbidity is increased among those with eating disorders and vice versa. Although there was some variation in comorbidity observed across eating disorder types, magnitudes of relative risks did not differ greatly.

From gut microbiota to host appetite: gut microbiota-derived metabolites as key regulators

Feelings of hunger and satiety are the key determinants for maintaining the life of humans and animals. Disturbed appetite control may disrupt the metabolic health of the host and cause various metabolic disorders. A variety of factors have been implicated in appetite control, including gut microbiota, which develop the intricate interactions to manipulate the metabolic requirements and hedonic feelings. Gut microbial metabolites and components act as appetite-related signaling molecules to regulate appetite-related hormone secretion and the immune system, or act directly on hypothalamic neurons. Herein, we summarize the effects of gut microbiota on host appetite and consider the potential molecular mechanisms. Furthermore, we propose that the manipulation of gut microbiota represents a clinical therapeutic potential for lessening the development and consequence of appetite-related disorders. Video abstract.

Association and Familial Coaggregation of Type 1 Diabetes and Eating Disorders: A Register-Based Cohort Study in Denmark and Sweden

OBJECTIVE

To ascertain the association and coaggregation of eating disorders and childhood-onset type 1 diabetes in families.

RESEARCH DESIGN AND METHODS

Using population samples from national registers in Sweden (n = 2,517,277) and Demark (n = 1,825,920), we investigated the within-individual association between type 1 diabetes and eating disorders and their familial coaggregation among full siblings, half siblings, full cousins, and half cousins. On the basis of clinical diagnoses, we classified eating disorders into any eating disorder (AED), anorexia nervosa (AN) and atypical AN, and other eating disorder (OED). Associations were determined with hazard ratios (HRs) with 95% CIs from Cox regressions.

RESULTS

Swedish and Danish individuals with a type 1 diabetes diagnosis had a greater risk of receiving an eating disorder diagnosis (HR [95% CI] Sweden: AED 2.02 [1.80-2.27], AN 1.63 [1.36-1.96], OED 2.34 [2.07-2.63]; Denmark: AED 2.19 [1.84-2.61], AN 1.78 [1.36-2.33], OED 2.65 [2.20-3.21]). We also meta-analyzed the results: AED 2.07 (1.88-2.28), AN 1.68 (1.44-1.95), OED 2.44 (2.17-2.72). There was an increased risk of receiving an eating disorder diagnosis in full siblings in the Swedish cohort (AED 1.25 [1.07-1.46], AN 1.28 [1.04-1.57], OED 1.28 [1.07-1.52]); these results were nonsignificant in the Danish cohort.

CONCLUSIONS

Patients with type 1 diabetes are at a higher risk of subsequent eating disorders; however, there is conflicting support for the relationship between having a sibling with type 1 diabetes and an eating disorder diagnosis. Diabetes health care teams should be vigilant about disordered eating behaviors in children and adolescents with type 1 diabetes.

A detailed hierarchical model of psychopathology: From individual symptoms up to the general factor of psychopathology

Much of our knowledge about the relationships among domains of psychopathology is built on the diagnostic categories described in the Diagnostic and Statistical Manual of Mental Disorders (DSM), with relatively little research examining the symptom-level structure of psychopathology. The aim of this study was to delineate a detailed hierarchical model of psychopathology-from individual symptoms up to a general factor of psychopathology-allowing both higher- and lower-order dimensions to depart from the structure of the DSM. We explored the hierarchical structure of hundreds of symptoms spanning 18 DSM disorders, in two large samples-one from the general population in Australia (n = 3175), and the other a treatment-seeking clinical sample from the USA (n = 1775). There was marked convergence between the two samples, offering new perspectives on higher-order dimensions of psychopathology. We also found several noteworthy departures from the structure of the DSM in the symptom-level data.