Reliability of lifetime history of bulimia nervosa. Comparison with major depression

Androgens impact on psychopathological variables according to CPRS, and EDI 2 scores: In women with bulimia nervosa, and eating disorder not otherwise specified

Bulimia nervosa (BN) is characterized by binge eating, compensatory behavior, over-evaluation of weight and shape, which often co-occur with symptoms of anxiety and depression. Depression is the most common comorbid diagnosis in women with eating disorders. The role of androgens in the pathophysiology of depression has been recognized in recent years. However, the research on psychopathological comorbidity and androgen levels in bulimic disease is sparse. This study aimed to investigate, if there were any correlations between the androgens, testosterone (T), dehydroepiandrosterone sulphate (DHEAS), androstenedione (A4), 5α-dihydrotestosterone, (5α-DHT), and test scores of psychopathological variables, in women with bulimia nervosa (BN), eating disorder not otherwise specified of purging subtype (EDNOS-P) assessed by CPRS, and EDI 2. Women with DSM-IV diagnosis of BN (n = 36), EDNOS-P (n = 27), and healthy control subjects (n = 58) evaluated for fifteen psychopathological variables, i.a. depressive symptoms, impulsivity, personal traits, as well as serum androgen levels. All women were euthyroid, and polycystic ovarian syndrome (PCOS) diagnosis was excluded. Although androgen levels were almost equal for all three groups, significant correlations between core psychopathological symptoms (9/15) of bulimia nervosa and the most potent endogenous androgen, 5α-DHT, was found only in the EDNOS-P group. The role of 5α-DHT in women is not fully elucidated. Both animal and human studies have shown that the brain is able to locally synthesize steroids de novo and is a target of steroid hormones. Maybe these results can be interpreted in the light of differences in androgen receptor variability, metabolism and origin of T and 5α-DHT.

Genetic and environmental components to self-induced vomiting

OBJECTIVE

We examined the association between the genetic and environmental factors contributing to the liability to having ever engaged in self-induced vomiting (SIV initiation) and the genetic and environmental factors contributing to regular SIV behaviors (weekly or daily) for weight control.

METHOD

SIV was assessed in 3,942 women from monozygotic twin pairs and 2,790 women from same-sex dizygotic twin pairs, aged 20-47, from the Swedish Twin study of Adults: Genes and Environment. A causal-contingent-common pathway model assessed the extent to which genetic and environmental factors that influence initiation of SIV also influence regular SIV behaviors.

RESULTS

In the best-fit model, genetic and individual-specific environmental factors influenced liability to SIV initiation. The genetic factors influencing regular SIV behaviors were the same as the genetic factors influencing SIV initiation. Additional individual-specific environmental factors that were unrelated to SIV initiation influenced regular SIV behaviors.

DISCUSSION

Our findings provide evidence that the underlying liabilities for SIV initiation and regular SIV lie on the same continuum given the degree of overlap in risk between SIV initiation and regular SIV behaviors. Further, the lack of specific genetic factors and the importance of individual-specific environmental factors for regular SIV behaviors highlight the significance of environmental factors in the etiology of eating disorder symptomatology and the non-deterministic nature of genetic factors. Finally, our results suggest that when it comes to preventing individuals from developing regular SIV behavior, intervening at an environmental level is warranted.

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.

Eating disorder symptomatology and substance use disorders: prevalence and shared risk in a population based twin sample

OBJECTIVE

Research shows a significant association between eating disorders (ED) and substance use disorders (SUD). The objective of this study is to examine the prevalence, chronology, and possibility of shared familial risk between SUD and ED symptomatology.

METHOD

Subjects included 1,206 monozygotic and 877 dizygotic adult female twins. ED symptomatology included anorexia (AN) and bulimia nervosa (BN) diagnosis, symptoms associated with diagnostic criteria, and BN symptom count. SUD included alcohol, illicit drug, and caffeine abuse/dependence. Generalized estimated equation modeling was used to examine phenotypic associations, and Choleksy decompositions were used to delineate the contribution of genes and environment to comorbidity.

RESULTS

There were no significant differences between SUD prevalence in women with AN and BN. Women with BN reported BN preceded SUD development while the reverse was true for AN. Twin analyses showed possible familial overlap between BN symptomatology and all SUD examined.

DISCUSSION

Results suggest an important difference in the chronology of EDs and SUDs. Women with BN may be turning to substances to dampen bulimic urges. Women with AN may be engaging in substance use initially in an effort to lose weight. Results also suggest familial factors contribute to the comorbidity between BN and SUD.

Incidence and outcomes of bulimia nervosa: a nationwide population-based study

BACKGROUND

Little is known about the epidemiology of bulimia nervosa outside clinical settings. We report the incidence, prevalence and outcomes of bulimia nervosa using for the first time a nationwide study design.

METHOD

To assess the incidence and natural course and outcomes of DSM-IV bulimia nervosa among women from the general population, women (n=2881) from the 1975-79 birth cohorts of Finnish twins were screened for lifetime eating disorders using a two-stage procedure consisting of a questionnaire screen and the Structured Clinical Interview for DSM-IV (SCID). Clinical recovery was defined as 1-year abstinence from bingeing and purging combined with a body mass index (BMI) 19 kg/m2.

RESULTS

The lifetime prevalence of DSM-IV bulimia nervosa was 2.3%; 76% of the women suffered from its purging subtype and 24% from the non-purging subtype. The incidence rate of bulimia nervosa was 300/100000 person-years at the peak age of incidence, 16-20 years, and 150/100000 at 10-24 years. The 5-year clinical recovery rate was 55.0%. Less than a third of the cases had been detected by health-care professionals; detection did not influence outcome. After clinical recovery from bulimia nervosa, the mean levels of residual psychological symptoms gradually decreased over time but many women continued to experience significantly more body image problems and psychosomatic symptoms than never-ill women.

CONCLUSIONS

Few women with bulimia nervosa are recognized in health-care settings. Symptoms of bulimia are relatively long-standing, and recovery is gradual. Many clinically recovered women experience residual psychological symptoms after attaining abstinence from bingeing and purging.

Psychosocial factors associated with broadly defined bulimia nervosa during early pregnancy: findings from the Norwegian mother and child cohort study

OBJECTIVE

The purpose of the present study was to investigate the relationship between psychosocial characteristics and broadly defined bulimia nervosa during early pregnancy, including factors associated with continuation, incidence and remission.

METHOD

A total of 41 157 women completed questionnaires at approximately gestation week 18, including items on eating disorders and psychosocial characteristics as a part of Norwegian Mother and Child Cohort Study conducted by the Norwegian Institute of Public Health.

RESULTS

Incident bulimia nervosa during the first trimester was significantly associated with symptoms of anxiety and depression and low self-esteem and life satisfaction, whereas remission was significantly associated with higher self-esteem and life satisfaction. Continuation was not significantly related to any of the psychosocial variables tested.

CONCLUSION

Onset of bulimia nervosa during pregnancy is associated with mood and anxiety symptoms. Remission of bulimic symptoms and new onset of bulimia nervosa are associated with opposite profiles of self-esteem, and life satisfaction measures.

Association between broadly defined bulimia nervosa and drug use disorders: common genetic and environmental influences

OBJECTIVE

Previous research has shown an association between bulimia (BN) and drug use disorders (DUD). The purpose of the present study was to investigate possible influences on the comorbidity between BN and DUD.

METHOD

Participants included 490 monozygotic and 354 dizygotic female twins and 930 females from opposite sex pairs. Multiple logistic regression analyses were used to test shared correlates and mediators. Bivariate twin analyses were used to investigate the contribution of genes and environment to the correlation between BN and DUD.

RESULTS

Depression, neuroticism, and childhood sexual abuse (CSA) mediated the association between BN and DUD regardless of which disorder was used as the dependent variable. Analyses also indicated genetic and nonshared environmental overlap between BN and DUD.

CONCLUSION

The association between BN and DUD is due mostly to overlapping genetic influences with a smaller contribution from nonshared environment. Depression, neuroticism, and CSA are likely important shared correlates.

Genetic epidemiology, endophenotypes, and eating disorder classification

OBJECTIVE

To explore how genetic epidemiology has informed the identification of endophenotypes and how endophenotypes may inform future classification of eating disorders.

METHOD

Literature review and synthesis.

RESULTS

Although a number of endo- and subphenotypes have been suggested for eating disorders, few reach the rigorous definitions developed for candidate endophenotypes.

CONCLUSION

Further study of endophenotypes and subphenotypes for eating disorders may assist with developing a more homogenous classification system that more closely reflects underlying biological mechanisms, and provides a clearer focus for the development of coherent models and treatments.

Prevalence and long-term course of lifetime eating disorders in an adult Australian twin cohort

OBJECTIVE

Few studies exist that have examined the spectrum and natural long-term course of eating disturbance in the community. We examine the lifetime prevalence and long-term course of anorexia nervosa (AN), bulimia nervosa (BN) and eating disorder not otherwise specified (EDNOS) in an adult female twin population.

METHOD

Female twins (n = 1002) from the Australian Twin Registry, aged 28-39 years, were assessed using the Eating Disorder Examination, revised to yield lifetime diagnostic information. For women with lifetime eating disorders, the assessment occurred, on average, 14.52 years (SD = 5.65) after onset of their disorder.

RESULTS

In accordance with other community studies, we found a 1.9% lifetime prevalence of AN, with an additional 2.4% who met the criteria for 'partial AN' (absence of amenorrhea). Criteria for BN were met by 2.9% of the women, an additional 2.9% of women met criteria for binge eating disorder, while 5.3% met criteria for purging disorder unaccompanied by binge eating (EDNOS-p). Eleven (7%) of the women with lifetime eating disorders had a current eating disorder. Each diagnostic group continued to be differentiated by current eating pathology from women without lifetime eating disorders. Although approximately 75% of the women had a good outcome, less than 50% of each diagnostic group was asymptomatic.

CONCLUSIONS

Eating disorders tend to improve over time often reaching subdiagnostic levels of severity, but only a minority of sufferers becomes asymptomatic. The DSM-IV diagnosis EDNOS needs to be considered in studies of the prevalence and course of eating disorders.

Lifetime prevalence estimates of major depression: an indirect estimation method and a quantification of recall bias

The measurement of lifetime prevalence of depression in cross-sectional surveys is biased by recall problems. We estimated it indirectly for two countries using modelling, and quantified the underestimation in the empirical estimate for one. A microsimulation model was used to generate population-based epidemiological measures of depression. We fitted the model to 1-and 12-month prevalence data from The Netherlands Mental Health Survey and Incidence Study (NEMESIS) and the Australian Adult Mental Health and Wellbeing Survey. The lowest proportion of cases ever having an episode in their life is 30% of men and 40% of women, for both countries. This corresponds to a lifetime prevalence of 20 and 30%, respectively, in a cross-sectional setting (aged 15-65). The NEMESIS data were 38% lower than these estimates. We conclude that modelling enabled us to estimate lifetime prevalence of depression indirectly. This method is useful in the absence of direct measurement, but also showed that direct estimates are underestimated by recall bias and by the cross-sectional setting.

The spectrum of eating disorders in young women: a prevalence study in a general population sample

OBJECTIVE

The present study aims to evaluate the prevalence and characteristics of the whole spectrum of eating disorders (ED) in a representative sample of young women.

METHOD

All female subjects aged 18 to 25 who resided in two areas (urban and suburban) of a large city were involved in the study. All women (N = 934) underwent a clinical interview which included the structured clinical interview for DSM-IV.

RESULTS

Lifetime anorexia nervosa (AN) and bulimia nervosa (BN) were diagnosed respectively in 2.0% and 4.6% of the subjects. The prevalence of lifetime atypical ED was 4.7% and that of binge eating disorder (BED) was 0.6%. The degree of urbanization has a significant impact on the prevalence of AN, BN, and BED. Social class, professional status, and education were not associated with an increased risk of reporting an ED, whereas the number of hypocaloric diets, having been a victim of childhood abuse, and, in BN, ever being overweight are significantly associated with ED.

CONCLUSIONS

Our findings have confirmed the importance of community studies to improve our knowledge about factors that have some influence on pathogenesis, treatment referral, and outcome.

Significant linkage on chromosome 10p in families with bulimia nervosa

Bulimia nervosa (BN) is strongly familial, and additive genetic effects appear to contribute substantially to the observed familiality. In turn, behavioral components of BN, such as self-induced vomiting, are reliably measured and heritable. To identify regions of the genome harboring genetic variants conferring susceptibility to BN, we conducted a linkage analysis of multiplex families with eating disorders that were identified through a proband with BN. Linkage analysis of the entire sample of 308 families yielded a double peak, with the highest nonparametric multipoint maximum LOD score (MLS), of 2.92, on chromosome 10. Given the high heritability of self-induced vomiting and the reliability with which it can be measured, we performed linkage analysis in a subset (n=133) of families in which at least two affected relatives reported a symptom pattern that included self-induced vomiting. The highest MLS (3.39) observed was on chromosome 10, between markers D10S1430 and D10S1423. These results provide evidence of the presence of a susceptibility locus for BN on chromosome 10p. Using simulations, we demonstrate that both of these scores, 2.92 and 3.39, meet the widely accepted criterion for genomewide significance. Another region on 14q meets the criterion for genomewide suggestive linkage, with MLSs of 1.97 (full sample) and 1.75 (subset) at 62 centimorgans from p-ter.

Medical and psychiatric morbidity in obese women with and without binge eating

OBJECTIVE

To determine the prevalence of obesity and binge eating in a population-based sample of female twins and to examine whether the presence of binge eating was associated with a greater risk for medical and psychiatric disorders in obese women.

METHOD

A population-based study of twins who were born between 1934 and 1971 and both members responded to a mailed questionnaire (individual response rate was conservatively estimated to be 64%). Data for the present study are from the first and third interview waves. In Wave 1 (1987-1989), we assessed 92% of the eligible individuals (N = 2,163), 90% face-to-face and the remainder by telephone. We assessed lifetime history of psychiatric disorders, major medical disorders, health limitations, health satisfaction, and an array of personality and attitudinal measures.

RESULTS

Obese women with binge eating reported greater health dissatisfaction and higher rates of major medical disorders than obese women without binge eating. Binge eating was also associated with higher lifetime prevalence of major depression, panic disorder, phobias, and alcohol dependence. Obese women with binge eating scored higher on neuroticism and symptom scales measuring depression, anxiety/phobia, and neurovegetative symptoms (i.e., insomnia, agitation, retardation, and obsessive-compulsive traits).

DISCUSSION

The presence of binge eating in obese women is a marker for greater medical and psychiatric morbidity.