Bulimia nervosa and major depression: a study of common genetic and environmental factors

The SARS-CoV-2 pandemic causes a dysfunctional dietary behavior: A German cross-sectional study

Background: Since the COVID-19 pandemic has been affected our daily lives, the global population has been exposed to permanent concerns and thus might suffer from the psychological burden. It is well known that psychological burdens can affect dietary behavior. Aim: The impact of a psychological burden on people, and in particular on their dietary patterns was investigated in this nationawide cross-sectional study. Methods: 7525 participants responded to the questionnaire regarding the psychological burden concerning the COVID-19 pandemic and their current dietary structure with changes in the pattern and food amount (between November 2020 and March 2021). Results: A pandemic-related dysfunction of dietary behavior was found. Some participants reported restrictive (conscious) food intake and as well impulsive food intake, which can be described as dysfunctional eating behaviors. In particular, younger persons and individuals who claimed an increased psychological burden reported dysfunctional dietary behavior. Data clearly show that psychological burdens affect an individual's dietary behavior. Conclusion: Public health strategies have to be developed to support individuals at risk to improve coping strategies. The long-term aim should be avoiding the maintenance of dysfunctional dietary behavior.

Exploring the possibility of parents' broad internalizing phenotype acting through passive gene-environment correlations on daughters' disordered eating

Twin studies demonstrate significant environmental influences and a lack of genetic effects on disordered eating before puberty in girls. However, genetic factors could act indirectly through passive gene-environment correlations (rGE; correlations between parents' genes and an environment shaped by those genes) that inflate environmental (but not genetic) estimates. The only study to explore passive rGE did not find significant effects, but the full range of parental phenotypes (e.g., internalizing symptoms) that could impact daughters' disordered eating was not examined. We addressed this gap by exploring whether parents' internalizing symptoms (e.g., anxiety, depressive symptoms) contribute to daughters' eating pathology through passive rGE. Participants were female twin pairs (aged 8-14 years; M = 10.44) in pre-early puberty and their biological parents (n = 279 families) from the Michigan State University Twin Registry. Nuclear twin family models explored passive rGE for parents' internalizing traits/symptoms and twins' overall eating disorder symptoms. No evidence for passive rGE was found. Instead, environmental factors that create similarities between co-twins (but not with their parents) and unique environmental factors were important. In pre-early puberty, genetic factors do not influence daughters' disordered eating, even indirectly through passive rGE. Future research should explore sibling-specific and unique environmental factors during this critical developmental period.

Genetic and environmental relationships between eating behavior and symptoms of anxiety and depression

PURPOSE

To assess gender-specific genetic and environmental correlations between depressive and anxiety symptoms, and concurrent and follow-up eating behavior in Korean twins and their family members.

METHODS

Center for Epidemiological Studies Depression Scale and State-Trait Anxiety Inventory were used to measure depressive and anxiety symptoms in subjects. To assess concurrent and follow-up relationships of the symptoms with eating behavior domains (restrained, emotional, and external eating), the Dutch Eating Behavior Questionnaire was administered to 2359 subjects at baseline (men, 48.5%; 42.0 ± 12.7 years; monozygotic twins, 33.7%) and to 1169 subjects at follow-up (men, 45.9%; 44.9 ± 11.6 years; monozygotic twins, 41.0%). A mixed linear model and bivariate analysis were applied.

RESULTS

After adjusting for age, twin and family effects, income, education, smoking status, alcohol use, exercise, and body mass index, depressive and anxiety symptoms were positively associated with concurrent and follow-up emotional and external eating, but not with restrained eating. The effect size of association with emotional eating increased in men in men over time, but decreased in women. Common genetic and environmental correlations showed a difference between genders, and their strength changed with time. Nevertheless, common genetic correlations were found between depressive and anxiety symptoms, and concurrent emotional eating, in both genders. There were common environmental correlations between anxiety symptoms, and concurrent restrained and emotional as well as follow-up emotional eating, in both genders.

CONCLUSIONS

There are similarities and differences in genetic and environmental relationships between depressive and anxiety symptoms and eating behaviors, based on gender and time of assessment.

LEVEL OF EVIDENCE

Level III, cohort study.

Eating Disorders in the Adolescent Population:

Adolescents become vulnerable to developing eating disorders as they mature. Very little is known about the prevalence, etiology, assessment, treatment, and outcome of eating disorders among adolescents. In general, research on eating disorders continues to be plagued with design flaws. Future studies need to be prospective research based on larger, more diverse samples of adolescents that represent all developmental stages of adolescence. Consistent diagnostic criteria and definitions of treatment interventions and outcomes also need to be employed. In addition, research should address the identification of protective and risk factors that predict who will actually develop an eating disorder.

Does shared genetic risk contribute to the co-occurrence of eating disorders and suicidality?

OBJECTIVE

There is a high level of co-occurrence of suicidality with eating disorders (EDs) but the reason for this is unknown. To test the hypothesis that suicidality and EDs share genetic risk contributing to the expression of both phenotypes.

METHOD

Female twins (N = 1,002) from the Australian Twin Registry, aged 28-40 years, were interviewed with diagnostic interviews. Lifetime diagnostic information relating to eating disorders [anorexia nervosa (AN), bulimia nervosa (BN), binge eating disorder, and purging disorder (PD)], suicidality (ranging transitory thoughts to suicide attempts), and major depression.

RESULTS

Any suicidal thoughts were reported by 24% of the sample, but prevalence of lifetime suicidality among female twins with EDs was much higher (43%), presence of an ED diagnosis more than doubling likelihood of suicidality (OR = 2.32, 95% CI: 1.63-3.31). AN and BN conveyed greatest risk of suicidality (OR = 2.03, 95% CI: 1.06-3.87; OR = 3.97, 95% CI: 2.01-7.85, respectively). Twin phenotype correlations showed monozygotic twins had uniformly higher estimates than dizygotic counterparts. A trivariate Cholesky model indicated a common genetic influence on suicidality and ED phenotypes (but not depression), and no nonshared environmental source.

DISCUSSION

Both cross twin phenotypic correlations and genetic modeling infer a common genetic pathway for suicidality and EDs, but further investigation is needed to elucidate whether this may constitute emotional dysregulation or other temperament-linked factors. Study findings also indicate that ED clients must be routinely assessed for presence of suicidality, independent of depression status.

Parental mental illness and eating disorders in offspring

OBJECTIVE

To investigate which parental mental illnesses are associated with eating disorders in their offspring.

METHOD

We used data from a record-linkage cohort study of 158,679 children aged 12-24 years at the end of follow-up, resident in Stockholm County from 2001 to 2007, to investigate whether different parental mental illnesses are risk factors for eating disorders in their offspring. The outcome measure was diagnosis of any eating disorder, either from an ICD or DSM-IV code, or inferred from an appointment at a specialist eating disorder clinic.

RESULTS

Mental illness in parents is a risk factor for eating disorders in female offspring (Adjusted Hazard Ratio (AHR) 1.57 (95% CI 1.42, 1.92), p < 0.0001). Risk of eating disorders is increased if there is a parental diagnosis of bipolar affective disorder (AHR 2.28 (95% CI 1.39, 3.72), p = 0.004), personality disorder (AHR 1.57 (95% CI 1.01, 2.44), p = 0.043) or anxiety/depression (AHR 1.57 (95% CI 1.32, 1.86), p < 0.0001). There is a lack of statistical evidence for an association with parental schizophrenia (AHR 1.41 (95% CI 0.96, 2.07), p = 0.08), and somatoform disorder (AHR 1.25 (95% CI 0.74, 2.13), p = 0.40). There is no support for a relationship between parental substance misuse and eating disorders in children (AHR 1.08 (95% CI 0.82, 1.43), p = 0.57).

DISCUSSION

Parental mental illness, specifically parental anxiety, depression, bipolar affective disorder, and personality disorders, are risk factors for eating disorders in their offspring.

Are there common familial influences for major depressive disorder and an overeating-binge eating dimension in both European American and African American female twins?

OBJECTIVE

Although prior studies have demonstrated that depression is associated with an overeating-binge eating dimension (OE-BE) phenotypically, little research has investigated whether familial factors contribute to the co-occurrence of these phenotypes, especially in community samples with multiple racial/ethnic groups. We examined the extent to which familial (i.e., genetic and shared environmental) influences overlapped between Major Depressive Disorder (MDD) and OE-BE in a population-based sample and whether these influences were similar across racial/ethnic groups.

METHOD

Participants included 3,226 European American (EA) and 550 African American (AA) young adult women from the Missouri Adolescent Female Twin Study. An adaptation of the Semi-Structured Assessment for the Genetics of Alcoholism (SSAGA) was administered to assess lifetime DSM-IV MDD and OE-BE. Quantitative genetic modeling was used to estimate familial influences between both phenotypes; all models controlled for age.

RESULTS

The best-fitting model, which combined racial/ethnic groups, found that additive genetic influences accounted for 44% (95% CI: 34%, 53%) of the MDD variance and 40% (25%, 54%) for OE-BE, with the remaining variances due to non-shared environmental influences. Genetic overlap was substantial (rg  = .61 [.39, .85]); non-shared environmental influences on MDD and OE-BE overlapped weakly (re  = .26 [.09, .42]).

DISCUSSION

Results suggest that common familial influences underlie MDD and OE-BE, and the magnitude of familial influences contributing to the comorbidity between MDD and OE-BE is similar between EA and AA women. If racial/ethnic differences truly exist, then larger sample sizes may be needed to fully elucidate familial risk for comorbid MDD and OE-BE across these groups.

The genetics of eating disorders

Over the past decade, considerable advances have been made in understanding genetic influences on eating pathology. Eating disorders aggregate in families, and twin studies reveal that additive genetic factors account for approximately 40% to 60% of liability to anorexia nervosa (AN), bulimia nervosa (BN), and binge eating disorder (BED). Molecular genetics studies have been undertaken to identify alterations in deoxyribonucleic acid sequence and/or gene expression that may be involved in the pathogenesis of disordered eating behaviors, symptoms, and related disorders and to uncover potential genetic variants that may contribute to variability of treatment response. This article provides an in-depth review of the scientific literature on the genetics of AN, BN, and BED including extant studies, emerging hypotheses, future directions, and clinical implications.

The role of depression and impulsivity in the psychopathology of bulimia nervosa

INTRODUCTION

The study aimed to analyze the role of depression and impulsivity in the psychopathology of bulimia nervosa (BN).

MATERIALS AND METHODS

Seventy female patients with DSM-IV BN, purging subtype, were assessed for eating-related symptoms, body dissatisfaction, affective symptoms, impulsivity, and personality traits. Factor analysis and structural equation modeling methods were used for statistical analysis.

RESULTS

BN appeared as a condition which incorporated 5 general dimensions: a) binge eating and compensatory behaviours; b) restrictive eating; c) body dissatisfaction; d) dissocial personality traits; and e) a cluster of features which was called «emotional instability» The 5 obtained dimensions can be grouped into 2 basic factors: body dissatisfaction/eating behaviour and personality traits/psychopathology. The first one contains the clinical items used for the definition of BN as a clinical condition in the DSM-V and the International Classification of Diseases 10, and reflects the morphology and the severity of the eating-related symptoms. The second dimension includes a cluster of symptoms (depressive symptoms, impulsivity, and borderline, self-defeating and dissocial personality traits) which could be regarded as the «psychopathological core» of BN and may be able to condition the course and the prognosis of BN.

A behavioral-genetic investigation of bulimia nervosa and its relationship with alcohol use disorder

Bulimia nervosa (BN) and alcohol use disorder (AUD) frequently co-occur and may share genetic factors; however, the nature of their association is not fully understood. We assessed the extent to which the same genetic and environmental factors contribute to liability to BN and AUD. A bivariate structural equation model using a Cholesky decomposition was fit to data from 7241 women who participated in the Swedish Twin study of Adults: Genes and Environment. The proportion of variance accounted for by genetic and environmental factors for BN and AUD and the genetic and environmental correlations between these disorders were estimated. In the best-fitting model, the heritability estimates were 0.55 (95% CI: 0.37; 0.70) for BN and 0.62 (95% CI: 0.54; 0.70) for AUD. Unique environmental factors accounted for the remainder of variance for BN. The genetic correlation between BN and AUD was 0.23 (95% CI: 0.01; 0.44), and the correlation between the unique environmental factors for the two disorders was 0.35 (95% CI: 0.08; 0.61), suggesting moderate overlap in these factors. The findings from this investigation provide additional support that some of the same genetic factors may influence liability to both BN and AUD.

Parental disorders, childhood abuse, and binge eating in a large community sample

OBJECTIVE

Genetic and nonshared environmental factors are implicated in the etiology of binge eating behaviors (BEB), with genetic risk expressed as parental psychopathology. Traumatic experiences including child abuse predict onset of BEB. It is not clear if each separately contribute to BEB, or whether parental pathology leads to abuse which in turn influences BEB.

METHOD

Data were obtained from the National Comorbidity Survey-Replication (N = 2960). Through structural equation modeling, we estimated unique and combined effects of mother's and father's internalizing (INT) and externalizing (EXT) disorders, and child abuse on BEB.

RESULTS

Parental INT and EXT psychopathology contributed to child abuse and BEB. Abuse predicted BEB and partially mediated associations between parental psychopathology and BEB.

DISCUSSION

Results emphasize the value of models that incorporate nature and nurture to understand risk for psychopathology in offspring, with childhood abuse being one mediator of how parental psychopathology may reflect genetic risk and influence environmental risk.

Eating Disorders: From Twin Studies to Candidate Genes and Beyond

Substantial effort has been put into the exploration of the biological background of eating disorders, through family, twin and molecular genetic studies. Family studies have shown that anorexia (AN) and bulimia nervosa (BN) are strongly familial, and that familial etiologic factors appear to be shared by both disorders. Twin studies often focus on broader phenotypes or subthreshold eating disorders. These studies consistently yielded moderate to substantial heritabilities. In addition, there has been a proliferation of molecular genetic studies that focused on Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV; American Psychiatric Association, 1994) AN and BN. Seven linkage regions have been identified in genome-wide screens. Many genetic association studies have been performed, but no consistent association between a candidate gene and AN or BN has been reported. Larger genetic association studies and collaborations are needed to examine the involvement of several candidate genes and biological pathways in eating disorders. In addition, twin studies should be designed to assist the molecular work by further exploring genetic determinants of endophenotypes, evaluating the magnitude of contribution to liability of measured genotypes as well as environmental risk factors related to eating disorders. In this manner twin and molecular studies can move the field forward in a mutually informative way.

Genetic and environmental influences on disordered eating and depressive symptoms

OBJECTIVE

Research suggests that shared genetic factors underlie relationships between eating disorder and depression diagnoses, but no studies to date have examined these associations using dimensional symptom measures. This study examined whether genetic associations observed between eating disorder and depression diagnoses extend to continuous measures of these phenotypes.

METHOD

The sample consisted of 292 young adult female twins from the Michigan State University Twin Registry. Disordered eating was measured using the Minnesota Eating Behavior Survey. Depressive symptoms were assessed using the Beck Depression Inventory.

RESULTS

Univariate twin models indicated that genetic factors accounted for 55% to 60% of the variance in disordered eating and depressive symptoms, with the remaining variance accounted for by nonshared environmental effects. Bivariate models indicated that genetic factors primarily accounted for associations between disordered eating and depressive symptoms (r(a) = .70).

DISCUSSION

Phenotypic associations between disordered eating and depressive symptoms appear to be due to common genetic factors.

Eating disorders and trauma history in women with perinatal depression

OBJECTIVE

Although the prevalence of perinatal depression (depression occurring during pregnancy and postpartum) is 10%, little is known about psychiatric comorbidity in these women. We examined the prevalence of comorbid eating disorders (ED) and trauma history in women with perinatal depression.

METHODS

A research questionnaire was administered to 158 consecutive patients seen in a perinatal psychiatry clinic during pregnancy (n=99) or postpartum (n=59). Measures included Structured Clinical Interview for DSM (SCID) IV-based questions for lifetime eating psychopathology and assessments of comorbid psychiatric illness including the State/Trait Anxiety Inventory (STAI), Patient Health Questionnaire (PHQ-9), Edinburgh Postnatal Depression Scale (EPDS), and Trauma Inventory.

RESULTS

In this cohort, 37.1% reported a putative lifetime ED history; 10.1% reported anorexia nervosa (AN), 10.1% reported bulimia nervosa (BN), 10.1% reported ED not otherwise specified-purging subtype (EDNOS-P), and 7.0% reported binge eating disorder (BED). Women with BN reported more severe depression (EPDS score, 19.1, standard deviation [SD 4.3], p=0.02; PHQ-severity 14.5, SD 7.4, p=0.02) than the referent group of women with perinatal depression and no ED history (EPDS 13.3, SD=6.1; PHQ 9.0, SD=6.2). Women with AN were more likely to report sexual trauma history than the referent group (62.5% vs. 29.3%, p<0.05), and those with BN were more likely report physical (50.0%, p<0.05) and sexual (66.7%, p<0.05) trauma histories.

CONCLUSIONS

ED histories were present in over one third of admissions to a perinatal psychiatry clinic. Women with BN reported more severe depression and histories of physical and sexual trauma. Screening for histories of eating psychopathology is important in women with perinatal depression.

Perfectionism and its relation to overevaluation of weight and shape and depression in an eating disorder sample

OBJECTIVE

To examine the relative association between psychopathology (depression and overevaluation of weight and shape) and measures of perfectionism and self-criticism in an eating disorder sample.

METHOD

Participants (n = 39) completed measures of independent variables (perfectionism and self-criticism) and dependent variables (depression and overevaluation of weight and shape).

RESULTS

Simultaneous multiple regression analyses suggest that clinical perfectionism has a unique association with depression. Self-criticism and clinical perfectionism had a stronger association with overevaluation of weight and shape than other measures of perfectionism.

DISCUSSION

Clinical perfectionism and self-criticism may be of more relevance than existing measures of multidimensional perfectionism in terms of explaining maintenance of depression and overevaluation of weight and shape.

Eating disorders: the current status of molecular genetic research

Anorexia nervosa (AN) and bulimia nervosa (BN) are complex disorders characterized by disordered eating behavior where the patient's attitude towards weight and shape, as well as their perception of body shape, are disturbed. Formal genetic studies on twins and families suggested a substantial genetic influence for AN and BN. Candidate gene studies have initially focused on the serotonergic and other central neurotransmitter systems and on genes involved in body weight regulation. Hardly any of the positive findings achieved in these studies were unequivocally confirmed or substantiated in meta-analyses. This might be due to too small sample sizes and thus low power and/or the genes underlying eating disorders have not yet been analyzed. However, some studies that also used subphenotypes (e.g., restricting type of AN) led to more specific results; however, confirmation is as yet mostly lacking. Systematic genome-wide linkage scans based on families with at least two individuals with an eating disorder (AN or BN) revealed initial linkage regions on chromosomes 1, 3 and 4 (AN) and 10p (BN). Analyses on candidate genes in the chromosome 1 linkage region led to the (as yet unconfirmed) identification of certain variants associated with AN. Genome-wide association studies are under way and will presumably help to identify genes and pathways involved in these eating disorders. The elucidation of the molecular mechanisms underlying eating disorders might improve therapeutic approaches.

Understanding the relation between anorexia nervosa and bulimia nervosa in a Swedish national twin sample

BACKGROUND

We present a bivariate twin analysis of anorexia nervosa and bulimia nervosa to determine the extent to which shared genetic and environmental factors contribute to liability to these disorders.

METHOD

Focusing on females from the Swedish Twin study of Adults: Genes and Environment (n = 7000), we calculated heritability estimates for narrow and broad anorexia nervosa and bulimia nervosa and estimated their genetic correlation.

RESULTS

In the full model, the heritability estimate for narrow anorexia nervosa (AN) was (a(2) = .57; 95% confidence interval [CI]: .00-.81) and for narrow bulimia nervosa (BN) (a(2) = .62; 95% CI: .08-.70), with the remaining variance accounted for by unique environmental factors. Shared environmental factors estimates were (c(2) = .00; 95% CI: .00-.67) for AN and (c(2) = .00; 95% CI: .00-.40) for BN. Moderate additive genetic (.46) and unique environmental (.42) correlations between AN and BN were observed. Heritability estimates for broad AN were lower (a(2) = .29; 95% CI: .04-.43) than for narrow AN, but estimates for broad BN were similar to narrow BN. The genetic correlation for broad AN and BN was .79, and the unique environmental correlation was .44.

CONCLUSIONS

We highlight the contribution of additive genetic factors to both narrow and broad AN and BN and demonstrate a moderate overlap of both genetic and unique environmental factors that influence the two conditions. Common concurrent and sequential comorbidity of AN and BN can in part be accounted for by shared genetic and environmental influences on liability although independent factors also operative.

Identification of new putative susceptibility genes for several psychiatric disorders by association analysis of regulatory and non-synonymous SNPs of 306 genes involved in neurotransmission and neurodevelopment

A fundamental difficulty in human genetics research is the identification of the spectrum of genetic variants that contribute to the susceptibility to common/complex disorders. We tested here the hypothesis that functional genetic variants may confer susceptibility to several related common disorders. We analyzed five main psychiatric diagnostic categories (substance-abuse, anxiety, eating, psychotic, and mood disorders) and two different control groups, representing a total of 3,214 samples, for 748 promoter and non-synonymous single nucleotide polymorphisms (SNPs) at 306 genes involved in neurotransmission and/or neurodevelopment. We identified strong associations to individual disorders, such as growth hormone releasing hormone (GHRH) with anxiety disorders, prolactin regulatory element (PREB) with eating disorders, ionotropic kainate glutamate receptor 5 (GRIK5) with bipolar disorder and several SNPs associated to several disorders, that may represent individual and related disease susceptibility factors. Remarkably, a functional SNP, rs945032, located in the promoter region of the bradykinin receptor B2 gene (BDKRB2) was associated to three disorders (panic disorder, substance abuse, and bipolar disorder), and two additional BDKRB2 SNPs to obsessive-compulsive disorder and major depression, providing evidence for common variants of susceptibility to several related psychiatric disorders. The association of BDKRB2 (odd ratios between 1.65 and 3.06) to several psychiatric disorders supports the view that a common genetic variant could confer susceptibility to clinically related phenotypes, and defines a new functional hint in the pathophysiology of psychiatric diseases.

The epidemiology of eating disorders in six European countries: results of the ESEMeD-WMH project

Few data are available to estimate the prevalence of eating disorders (EDs) and their correlates in the community. This paper reports data on EDs obtained in the framework of the ESEMeD project, aimed at investigating the prevalence of non-psychotic mental disorders in six European countries (Belgium, France, Germany, Italy, the Netherlands and Spain), using a new version of the Composite International Diagnostic Interview. The ESEMeD study was a general population cross-sectional household survey. In total, 21,425 respondents aged 18 or older provided data for the project between January 2001 and August 2003. A subsample (N=4139) underwent a detailed investigation on EDs. Lifetime estimated prevalence of anorexia nervosa, bulimia nervosa, binge eating disorder, sub-threshold binge eating disorder, and any binge eating were 0.48%, 0.51%, 1.12%, 0.72%, and 2.15%, respectively, and they were 3-8 times higher among women for all EDs. However, since people under 18 were excluded from this study, our prevalence should be taken as lower-bound estimate of real frequencies. Indeed, cumulative lifetime prevalence analysis showed that the majority of eating disorders had their initial onset between 10 and 20 years of age. Role impairment and comorbidity with other mental disorders were highly common, yet only small proportions of patients with a lifetime diagnosis of EDs requested medical treatment. It still has to be proven whether early diagnostic identification and access to specialized care can reduce the burden caused by these disorders.

The association of anxiety disorders and obsessive compulsive personality disorder with anorexia nervosa: evidence from a family study with discussion of nosological and neurodevelopmental implications

BACKGROUND

To investigate the association of anorexia nervosa with anxiety disorders through use of a case-control family study design.

METHOD

Lifetime prevalence of anxiety disorders and obsessive compulsive personality disorder was determined among 574 first-degree relatives of 152 probands with anorexia nervosa and compared to rates observed among 647 first-degree relatives of 181 never-ill control probands.

RESULTS

Adjusting for comorbidity of the same illness in the proband, relatives of probands with anorexia nervosa, had a significantly higher prevalence of generalized anxiety, obsessive compulsive disorder, separation anxiety disorder, social phobia, panic disorder, and obsessive compulsive personality disorder compared to relatives of never-ill control probands.

CONCLUSION

Anorexia nervosa may share familial liability factors in common with various anxiety phenotypes. In suggesting that a transmitted propensity for anxiety is a key aspect of vulnerability in anorexia nervosa, the findings point to research developments in the affective neurosciences, specifically the neurocircuitry of fear and anxiety, as a heuristic framework in which to interpret aspects of premorbid temperamental anxieties and clinical symptoms.

Atypical depression, somatic depression and anxious depression in women: are they gender-preferred phenotypes?

BACKGROUND

Both depression and anxiety disorders affect women at rates significantly greater than men. Women also have a documented higher frequency of comorbid depression and anxiety disorders, and a three-fold higher prevalence of atypical depression.

HYPOTHESES

These gender differences are mainly due to specific depressive phenotypes including anxious depression and atypical depression. The prevalence of comorbid anxiety and depression strongly suggests overlap of pathophysiological mechanisms-which in women are also affected by fluctuations in gonadal hormones. Similar efficacy of serotonergic antidepressants as treatment for anxiety disorders as well as depressions further underscores the blurred boundaries between these two descriptive entities.

CONCLUSIONS

Symptoms of depression and anxiety may be a departure point for differential diagnosis in which dimensionally-based phenotypes substantiated by pathobiology would replace current descriptive entities. It is suggested that at least some biologically-based dysphorias may be specific to women, ensuing from the combination of specific vulnerabilities, and complex interactions between brain mechanisms and gonadal hormones.

The prevalence and correlates of eating disorders in the National Comorbidity Survey Replication

BACKGROUND

Little population-based data exist on the prevalence or correlates of eating disorders.

METHODS

Prevalence and correlates of eating disorders from the National Comorbidity Replication, a nationally representative face-to-face household survey (n = 9282), conducted in 2001-2003, were assessed using the WHO Composite International Diagnostic Interview.

RESULTS

Lifetime prevalence estimates of DSM-IV anorexia nervosa, bulimia nervosa, and binge eating disorder are .9%, 1.5%, and 3.5% among women, and .3% .5%, and 2.0% among men. Survival analysis based on retrospective age-of-onset reports suggests that risk of bulimia nervosa and binge eating disorder increased with successive birth cohorts. All 3 disorders are significantly comorbid with many other DSM-IV disorders. Lifetime anorexia nervosa is significantly associated with low current weight (body-mass index <18.5), whereas lifetime binge eating disorder is associated with current severe obesity (body-mass index > or =40). Although most respondents with 12-month bulimia nervosa and binge eating disorder report some role impairment (data unavailable for anorexia nervosa since no respondents met criteria for 12-month prevalence), only a minority of cases ever sought treatment.

CONCLUSIONS

Eating disorders, although relatively uncommon, represent a public health concern because they are frequently associated with other psychopathology and role impairment, and are frequently under-treated.

Lifetime psychiatric comorbidity of alcohol dependence and bulimia nervosa in women

Previous work from our group revealed two groups of women with bulimia nervosa (BN), one with, and one without alcohol dependence (AD). The current study sought to determine whether women with lifetime BN and AD (BN+AD+) were more similar to women with BN and no AD (BN+AD-) or to women with AD and no BN (BN-AD+) in terms of lifetime psychiatric comorbidity and psychological functioning. Data on BN and AD from 407 female relatives in a family study of alcoholism were used to create three mutually exclusive groups: BN+AD+ (n=30), BN+AD- (n=55), and BN-AD+ (n=322). Bivariate analyses revealed fewer differences between BN+AD+ and BN-AD+ women than between BN+AD+ and BN+AD- women. BN+AD+ women were more likely than BN+AD- women to have drug dependence, conduct disorder, and suicidality, and were more likely to have major depression, lower GAF scores, and to engage in unsafe sex than both BN+AD- and BN-AD+ women. After adjusting for other psychopathology and demographic variables, BN+AD+ women were more likely than BN+AD- women to have major depression, drug dependence, and tobacco dependence and more likely than BN-AD+ women to have major depression and obsessive-compulsive disorder. These results suggest that BN+AD+ women exhibit more severe psychopathology than either BN+AD- or BN-AD+ women and may represent a distinct subgroup within bulimia nervosa or alcohol dependence.

The developmental association between eating disorders symptoms and symptoms of depression and anxiety in juvenile twin girls

OBJECTIVE

We investigated the role of genetic and environmental factors in the developmental association among symptoms of eating disorders, depression, and anxiety syndromes in 8-13-year-old and 14-17-year-old twin girls.

METHODS

Multivariate genetic models were fitted to child-reported longitudinal symptom data gathered from clinical interview on 408 MZ and 198 DZ female twin pairs from the Virginia Twin Study of Adolescent Behavioural Development (VTSABD).

RESULTS

Model-fitting revealed distinct etiological patterns underlying the association among symptoms of eating disorders, depression, overanxious disorder (OAD), and separation anxiety disorder (SAD) during the course of development: 1) a common genetic factor influencing liability to all symptoms - of early and later OAD, depression, SAD, and eating symptoms; 2) a distinct genetic factor specifically indexing liability to early eating disorders symptoms; 3) a shared environmental factor specifically influencing early depression and early eating disorders symptoms; and 4) a common environmental factor affecting liability to symptoms of later eating disorders and both early and later separation anxiety.

CONCLUSIONS

These results suggest a pervasive genetic effect that influences liability to symptoms of over-anxiety, separation anxiety, depression, and eating disorder throughout development, a shared environmental influence on later adolescent eating problems and persistent separation anxiety, genetic influences specific to early eating disorders symptoms, and a shared environmental factor influencing symptoms of early eating and depression.

Comorbidity of bipolar and eating disorders: distinct or related disorders with shared dysregulations?

BACKGROUND

The co-occurrence of bipolar and eating disorders, though of major clinical and public health importance, remains relatively unexamined.

METHODS

In reviewing the literature on this comorbidity, we compared bulimia, anorexia nervosa, bulimia nervosa, binge eating disorders and bipolar disorders on phenomenology, course, family history, biology, and treatment response.

RESULTS

Epidemiological studies show an association between subthreshold bipolar disorder and eating disorders in adolescents, and between hypomania and eating disorders, especially binge eating behavior, in adults. Of the clinical studies, most show that patients with bipolar disorder have elevated rates of eating disorders, and vice versa. Finally, the phenomenology, course, comorbidity, family history, and pharmacologic treatment response of these disorders show considerable overlap on all of these parameters. In particular, on phenomenologic grounds--eating dysregulation, mood dysregulation, impulsivity and compulsivity, craving for activity and/or exercise--we find many parallels between bipolar and eating disorders. Overall, the similarities between these disorders were more apparent when examined in their spectrum rather than full-blown expressions.

LIMITATIONS

Despite an extensive literature on each of these disorders, studies examining their overlap across all these parameters are relatively sparse and insufficiently systematic.

CONCLUSIONS

Nonetheless, the reviewed literature leaves little doubt that bipolar and eating disorders--particularly bulimia nervosa and bipolar II disorder--are related. Although several antidepressants and mood stabilizers have shown promise for eating disorders, their clinical use when these disorders co-exist with bipolarity is still very much of an art. We trust that this review will stimulate more rigorous research in their shared putative underlying psychobiologic mechanisms which, in turn, could lead to more rational targeted treatments.

Are there subgroups of bulimia nervosa based on comorbid psychiatric disorders?

OBJECTIVE

The current study sought to determine whether there are subtypes of bulimia nervosa (BN) differentiated by comorbid psychiatric disorders.

METHOD

Data on comorbid psychiatric diagnoses in female relatives of probands and controls in the Collaborative Study of the Genetics of Alcoholism (COGA) who met criteria for BN (as outlined in the 3rd Rev. ed. of the Diagnostic and Statistical Manual of Mental Disorders) were analyzed using latent class analysis. Resulting latent classes were compared on a variety of variables related to impulsive behaviors and psychological functioning.

RESULTS

The best-fitting solution, a two-class model, yielded one class (72%) characterized by substance dependence, depression, antisocial personality disorder (ASPD), and anxiety disorders, and another characterized by depression. The highly comorbid class had more suicidality, more daily smokers, sought help for emotional problems, and had lower Global Assessment of Functioning (GAF) scores compared with those in the comorbid depression only class.

DISCUSSION

Latent class findings suggest the existence of two classes of BN differentiated by substance dependence, impulsive behaviors, and poorer psychological functioning.

Coming to Terms With Risk Factors for Eating Disorders: Application of Risk Terminology and Suggestions for a General Taxonomy

The aims of the present review are to apply a recent risk factor approach (H. C. Kraemer et al., 1997) to putative risk factors for eating disorders, to order these along a timeline, and to deduce general taxonomic questions. Putative risk factors were classified according to risk factor type, outcome (anorexia nervosa, bulimia nervosa, binge-eating disorder, full vs. partial syndromes), and additional factor characteristics (specificity, potency, need for replication). Few of the putative risk factors were reported to precede the onset of the disorder. Many factors were general risk factors; only few differentiated between the 3 eating disorder syndromes. Common risk factors from longitudinal and cross-sectional studies were gender, ethnicity, early childhood eating and gastrointestinal problems, elevated weight and shape concerns, negative self-evaluation, sexual abuse and other adverse experiences, and general psychiatric morbidity. Suggestions are made for the conceptualization of future risk factor studies.

Are eating disorders culture-bound syndromes? Implications for conceptualizing their etiology

The authors explore the extent to which eating disorders, specifically anorexia nervosa (AN) and bulimia nervosa (BN), represent culture-bound syndromes and discuss implications for conceptualizing the role genes play in their etiology. The examination is divided into 3 sections: a quantitative meta-analysis of changes in incidence rates since the formal recognition of AN and BN, a qualitative summary of historical evidence of eating disorders before their formal recognition, and an evaluation of the presence of these disorders in non-Western cultures. Findings suggest that BN is a culture-bound syndrome and AN is not. Thus, heritability estimates for BN may show greater variability cross-culturally than heritability estimates for AN, and the genetic bases of these disorders may be associated with differential pathoplasticity.

A practice guideline for treatment of eating disorders in children and adolescents

Eating disorders are diseases of both the body and the psyche. Early treatment focuses on restoration of nutritional status and somatic health, including psycho-educational counselling and support offered to the patient and his/her family. Diagnosis and treatment require a multidisciplinary approach. Psychological factors related to the condition should be assessed. The most severe weight loss should be reversed before psychotherapeutic treatment. Nutritional counselling is recommended, and the benefits of individual and/or family therapy are considered in accordance with the patient's age, development, symptomatology and comorbid psychiatric disorders. Medication is useful in the treatment of bulimia nervosa and certain comorbid symptoms of anorexia nervosa. Early admission to treatment and active therapy are associated with a more favourable prognosis.

The children of mothers with eating disorders

There is good evidence that children of parents with psychological disorders are themselves at increased risk of disturbances in their development. Although there has been considerable research on a variety of disorders such as depression and alcohol, research on the children of parents with eating disorders has been relatively recent. This paper aims to review the evidence and covers a number of areas, including genetic factors, pregnancy, the perinatal and postpartum period, infancy, and the early years of life, focusing on feeding and mealtimes, general parenting functions, and growth. This is followed by a consideration of psychopathology in the children, parental attitudes to children's weight and shape, and adolescence. What is clear is that although there are numerous case reports and case series, the number of systematic controlled studies is relatively small, and almost nothing has been written about the children of fathers with eating disorders. What is evident from the available evidence is that children of mothers with eating disorders are at increased risk of disturbance, but that the risk depends on a variety of factors, and that difficulties in the children are far from invariable. The paper concludes by summarizing five broad categories of putative mechanisms, based on the evidence to date, by which eating disturbance in parents can influence child development.

The evolving genetic foundations of eating disorders

Data described earlier are clear in establishing a role for genes in the development of eating abnormalities. Estimates from the most rigorous studies suggest that more than 50% of the variance in eating disorders and disordered eating behaviors can be accounted for by genetic effects. These high estimates indicate a need for studies identifying the specific genes contributing to this large proportion of variance. Twin and family studies suggest that several heritable characteristics that are commonly comorbid with AN and BN may share genetic transmission with these disorders, including anxiety disorders or traits, body weight, and possibly major depression. Moreover, some developmental research suggests that the genes involved in ovarian hormones or the genes that these steroids affect also may be genetically linked to eating abnormalities. Molecular genetic research of these disorders is in its infant stages. However, promising areas for future research have already been identified (e.g., 5-HT2A receptor gene, UCP-2/UCP-3 gene, and estrogen receptor beta gene), and several large-scale linkage and association studies are underway. These studies likely will provide invaluable information regarding the appropriate phenotypes to be included in genetic studies and the genes with the most influence on the development of these disorders.

Candidate gene polymorphisms in eating disorders

Anorexia nervosa and bulimia nervosa are complex disorders characterized by disordered eating behaviour. Attitudes towards weight and shape as well as the perception of body shape are disturbed. A substantial genetic influence on these disorders has been suggested by formal genetic studies. Obsessive-compulsive behaviour, perfectionism and anxious personality traits seem to occur premorbidly in several patients. Disturbances of neurotransmitter, neuropeptide and neuroendocrine systems have been reported in acutely ill and followed-up patients. Hence, these systems might be involved in the etiology of these eating disorders.Genetic studies on candidate genes have mainly focussed on the serotonergic system and on genes involved in body weight regulation. Up to now, polymorphisms and variations in various genes (e.g. genes for 5-HT receptors, leptin gene, melanocortin MC(4) receptor gene) have been assessed for association and transmission disequilibrium pertaining to anorexia nervosa and/or bulimia nervosa. Most of the studies yielded negative results. Four studies of a polymorphism (-1438 G/A) within the promoter of the 5-HT(2A) gene (5-HT(2A)) revealed an association of the A-allele to anorexia nervosa. However, three studies could not confirm this result. Furthermore, a meta-analysis did not support the positive association. Currently, combined efforts within the European Union will answer the question of whether or not the A-allele is involved in the predisposition to anorexia nervosa. A transmission disequilibrium test is being performed in about 300 trios consisting of a patient with anorexia nervosa and both parents. As candidate gene approaches did not unequivocally identify susceptibility genes (alleles) for anorexia nervosa or bulimia nervosa, systematic model-free genome-wide screenings should also be performed in order to identify currently unknown genes involved in eating disorders. This kind of approach has already been initiated for anorexia nervosa. Genetic research on eating disorders will hopefully lead to new pharmacological treatment strategies.

Assessing the relevance of the hopelessness theory of depression to women with disordered eating

OBJECTIVE

The aim of this study was to investigate the relevance of the hopelessness theory of depression to women with partial-syndrome eating disorders.

METHOD

Three groups of women, one meeting criteria for eating disorders not otherwise specified (EDNOS), one with major depression, and a control group, completed the Balanced Attributional Style Questionnaire, the Eating Disorders Examination Questionnaire, and the Beck Depression Inventory.

RESULTS

Once levels of depression were controlled, all three groups differed significantly with respect to their attributional style for bad events, with the depressed group showing the greatest tendency to attribute the causes of negative life events to internal factors. However, with respect to the attributional style for good events, the depressed and control group displayed similar styles of attribution, whereas the EDNOS group showed a significantly more dysfunctional style, being more likely to attribute positive events to external factors.

DISCUSSION

These findings are discussed in terms of their implications for specific therapeutic interventions with disordered eating.

Twin studies and the etiology of eating disorders

OBJECTIVE

To evaluate the major twin studies of eating disorders in order to consider the empirical standing of the suggestion that these disorders, notably bulimia nervosa, are largely genetically determined.

METHOD

Examination of the relevant twin studies and the methods used.

RESULTS

The findings of the twin studies are inconsistent and difficult to interpret, with estimates for the heritability of liability to bulimia nervosa ranging from 0% to 83%, and from 0% to 70% for anorexia nervosa. Methodological reasons for this variability include issues of definition of phenotype, diagnostic reliability, violation of the equal environments assumption, and small sample sizes. Many of these issues also apply to twin studies of other psychiatric disorders.

CONCLUSIONS

The heritability of eating disorders remains unknown. A broad view on the etiology of eating disorders should be maintained, with a focus on environmental mechanisms and gene-environment interactions, as well as continuing genetic studies.

Risk factors for bulimia nervosa: a controlled study of parental psychiatric illness and divorce

Twenty five women with normal-weight bulimia nervosa were compared with 25 age- and weight-matched women without bulimia nervosa on measures of parental psychiatric illness. Case and control probands, as well as their parents, completed the Family History Research Diagnostic Criteria (FH-RDC) interview and a battery of self-report instruments. Case probands and controls were divided into two groups based on evidence for parental psychiatric illness. The assignment of parental psychiatric illness was made by (a) a positive parental history of alcoholism or depression from the FH-RDC; or (b) evidence of parental major depression, alcoholism, or personality disorder from the self-report measures. Parental psychiatric illness occurred significantly more frequently for case probands compared to the control probands (64% vs. 24%, odds ratio = 5.6, 95% Cl = 1.7-19.2). Parental psychiatric illness was also associated with parental divorce (Fisher's exact p = .023) and a trend toward lower ratings of paternal but not maternal relationship by case probands. This study suggests parental psychiatric illness may be a risk factor for bulimia nervosa and may contribute to environmental effects through increased rates of divorce and impaired paternal relationships.

Parental treatment and the equal environment assumption in twin studies of psychiatric illness

The validity of the twin method depends on the equal environment assumption (EEA)--that monozygotic (MZ) and dizygotic (DZ) twins are equally correlated in their exposure to environmental factors of aetiological importance for the trait under study. Parents may treat MZ twins more similarly than DZ twins thereby potentially violating the EEA. We tested this hypothesis for four common psychiatric disorders (major depression, generalized anxiety disorder, phobia, and alcoholism) in a population-based sample of female-female twin pairs where analyses indicate sufficient statistical power meaningfully to test the EEA. Mother's and father's beliefs about their twins' zygosity disagreed with assigned zygosity in approximately 20% of cases, often because of what they were told about their twins' zygosity at their birth. By structural equation model-fitting, we found no evidence that mother's or father's perceived zygosity influenced twin resemblance for any of the disorders. Compared to parents of DZ twins, parents of MZ twins were more likely to report that, in rearing their twins, they emphasized their similarities more than their differences. However, by model-fitting, mothers' and fathers' approach to raising twins had no significant influence on twin resemblance for the four examined psychiatric disorders. These results suggest that the differential treatment of MZ and DZ twins by their parents is unlikely to represent a significant bias in twin studies of these major psychiatric disorders.

Behavioral frequency and psychological commitment: necessary concepts in the study of excessive exercising

Efforts to understand the associations among exercising, personality factors, and disordered eating have been the focus of much debate. However, research has been plagued by inconsistent findings, and there is evidence that classification and measurement differences are fundamental to these problems. To date, there are no studies which have defined exercise as a multifaceted construct. The purposes of this study were to establish the factor structure of a questionnaire developed to assess the core features believed to characterize excessive exercisers and to assess relationships between exercise (operationally defined as a function of behaviors and attitudes) and a number of putative risk factors. Results indicated that exercise was strongly related to weight preoccupation among women and men and that, among men, obsessive-compulsiveness was also positively related--findings which support claims that exercising and dieting tend to coexist, and they are associated with an obsessive-compulsive personality profile.

Panic disorder in women: a population-based twin study

Previous studies based on probands from clinical samples suggest that panic disorder aggregates strongly in families and may be due to a highly penetrant single major locus. In this study we examine panic disorder as assessed at blind, structured psychiatric interview in 2163 women from a population-based twin registry. DSM-III-R diagnoses were assigned at a narrow and at a broad level both by clinician review and by computer algorithm. The familial aggregation of panic disorder in this sample was only modest. The relatively small number of affected individuals prevented a definitive resolution of competing genetic and non-genetic models of familial transmission. Although there was some inconsistency across diagnostic approaches, most results suggested that the familial aggregation of panic disorder was due largely to genetic factors. Using a multifactorial-threshold model, the best estimates of the heritability of liability ranged from 30 to 40%. From a familial perspective, panic disorder with phobic avoidance appears to represent a more severe form of the syndrome than panic disorder without avoidance. Our results, which suggest that in the general population panic disorder is only a moderately heritable condition, are at variance with results from several previous investigations based on clinically ascertained samples.