The relationship between obstetric complications and temperament in eating disorders: a mediation hypothesis

Mechanisms by which adverse childhood experiences, other traumas and PTSD influence the health and well-being of individuals with eating disorders throughout the life span

BACKGROUND

Multiple published sources from around the world have confirmed an association between an array of adverse childhood experiences (ACEs) and other traumatic events with eating disorders (EDs) and related adverse outcomes, including higher morbidity and mortality.

METHODS

In keeping with this Special Issue's goals, this narrative review focuses on the ACEs pyramid and its purported mechanisms through which child maltreatment and other forms of violence toward human beings influence the health and well-being of individuals who develop EDs throughout the life span. Relevant literature on posttraumatic stress disorder (PTSD) is highlighted when applicable.

RESULTS

At every level of the pyramid, it is shown that EDs interact with each of these proclaimed escalating mechanisms in a bidirectional manner that contributes to the predisposition, precipitation and perpetuation of EDs and related medical and psychiatric comorbidities, which then predispose to early death. The levels and their interactions that are discussed include the contribution of generational embodiment (genetics) and historical trauma (epigenetics), social conditions and local context, the ACEs and other traumas themselves, the resultant disrupted neurodevelopment, subsequent social, emotional and cognitive impairment, the adoption of health risk behaviors, and the development of disease, disability and social problems, all resulting in premature mortality by means of fatal complications and/or suicide.

CONCLUSIONS

The implications of these cascading, evolving, and intertwined perspectives have important implications for the assessment and treatment of EDs using trauma-informed care and trauma-focused integrated treatment approaches. This overview offers multiple opportunities at every level for the palliation and prevention of EDs and other associated trauma-related conditions, including PTSD.

The role of prenatal and perinatal factors in eating disorders: a systematic review

Numerous studies showed that factors influencing fetal development and neonatal period could lead to lasting alterations in the brain of the offspring, in turn increasing the risk for eating disorders (EDs). This work aims to systematically and critically review the literature on the association of prenatal and perinatal factors with the onset of EDs in the offspring, updating previous findings and focusing on anorexia nervosa (AN) and bulimia nervosa (BN). A systematic literature search was performed on Pubmed, PsycINFO, and Scopus. The drafting of this systematic review was conducted following the PRISMA statement criteria and the methodological quality of each study was assessed by the MMAT 2018. A total of 37 studies were included in this review. The factors that showed a more robust association with AN were higher maternal age, preeclampsia and eclampsia, multiparity, hypoxic complications, prematurity, or being born preterm (< 32 weeks) and small for gestational age or lower birth size. BN was only associated with maternal stress during pregnancy. Many methodological flaws emerged in the considered studies, so further research is needed to clarify these inconsistencies. Altogether, data are suggestive of an association between prenatal and perinatal factors and the onset of EDs in the offspring. Nevertheless, given the methodological quality of the available literature, firm conclusions cannot be drawn and whether this vulnerability is specific to EDs or mental disorders remains to be defined. Also, a strong need for longitudinal and well-designed studies on this topic emerged.

Maternal eating disorders and perinatal outcomes: A three-generation study in the Norwegian Mother and Child Cohort Study

Previous studies of the relationship between maternal eating disorders and adverse perinatal outcomes have failed to control for familial transmission of perinatal phenotypes, which may confound the reported association. In a unique design afforded by the Norwegian Mother and Child Cohort Study and Medical Birth Registry of Norway, we linked three generations through birth register records and maternal-reported survey data to investigate whether maternal eating disorders increase risk after parsing out the contribution of familial transmission of perinatal phenotypes. The samples were 70,881 pregnancies in grandmother-mother-child triads for analyses concerning eating disorder exposure during pregnancy and 52,348 for analyses concerning lifetime maternal eating disorder exposure. As hypothesized, eating disorders predicted a higher incidence of perinatal complications even after adjusting for grandmaternal perinatal phenotypes. For example, anorexia nervosa immediately prior to pregnancy was associated with smaller birth length (relative risk = 1.62; 95% CI [1.20, 2.14]), bulimia nervosa with induced labor (relative risk = 1.21; 95% CI [1.07, 1.36]), and binge-eating disorder with several delivery complications, larger birth length (relative risk = 1.25; 95% CI [1.17, 1.34]), and large-for-gestational-age (relative risk = 1.04; 95% CI [1.01, 1.06]). Maternal pregravid body mass index and gestational weight mediated most associations. Our results support that exposure to eating disorders increases the risk for negative health outcomes in pregnant women and their babies. (PsycINFO Database Record

Obstetric complications and eating disorders: a replication study

OBJECTIVE

To provide data about the role of obstetric complications (OCs) in a large and well-characterized sample of patients with anorexia nervosa (AN) or bulimia nervosa (BN).

METHOD

The new sample consists of 150 patients with AN and 35 patients with BN, and 73 healthy women; statistical analyses were performed on the new sample alone and on the larger sample created by merging the new dataset with the previous one (264 AN, 108 BN, and 624 healthy women). All data about OCs were collected blind to diagnostic status.

RESULTS

OC rates in the replication sample were similar to those of our previous studies. In the whole sample, the risk of developing AN was significantly associated with the occurrence and number of pregnancy, delivery, hypoxic, and dysmaturity complications. The risk of developing BN was significantly associated with dysmaturity complications. Signs of retarded fetal growth (being small and short for gestational age, short head circumference) significantly distinguished BN patients from both AN and healthy individuals. Significantly higher number of OCs were found in the binge eating/purging type of AN, in comparison with restricting AN patients.

DISCUSSION

Our study provides further evidence of the role of OCs as putative risk factors for the development of eating disorders, showing different pathways between AN and BN.

Eating Disorders, Pregnancy, and the Postpartum Period: Findings from the Norwegian Mother and Child Cohort Study (MoBa)

This review summarizes studies on eating disorders in pregnancy and the postpartum period that have been conducted as part of the broader Norwegian Mother and Child Cohort Study (MoBa). Prior to the 2000s, empirical literature on eating disorders in pregnancy was sparse and consisted mostly of studies in small clinical samples. MoBa has contributed to a new era of research by making population-based and large-sample research possible. To date, MoBa has led to 19 studies on diverse questions including the prevalence, course, and risk correlates of eating disorders during pregnancy and the postpartum. The associations between eating disorder exposure and pregnancy, birth and obstetric outcomes, and maternal and offspring health and well-being, have also been areas of focus. The findings indicate that eating disorders in pregnancy are relatively common and appear to confer health risks to mother and her child related to sleep, birth outcomes, maternal nutrition, and child feeding and eating.

Effects of obstetric complications on volume and functional connectivity of striatum in anorexia nervosa patients

OBJECTIVE

To investigate the volume and functional connectivity of dorsal and ventral striatal nuclei in anorexia nervosa (AN) and their relationship with early exposure to obstetric complications.

METHOD

Fifty-one patients with lifetime AN (35 acute, 16 recovered) and 34 healthy controls underwent high-resolution and resting-state functional magnetic resonance imaging.

RESULTS

The AN group showed reduced functional connectivity of the putamen compared with healthy women, and this reduction was more evident in patients with lifetime binge eating/purging. Both acute and recovered AN groups showed a larger left accumbens area compared with that of healthy women. The functional connectivity of bilateral nucleus accumbens and putamen showed significant negative correlations with number of obstetric complications in the AN group.

DISCUSSION

This study supports the hypothesis that AN is associated with structural and functional alterations of striatal networks, and reveals the possible role of obstetric complications in the pathogenesis of striatal dysfunction.

Associations between birth characteristics and eating disorders across the life course: findings from 2 million males and females born in Sweden, 1975-1998

Birth characteristics predict a range of major physical and mental disorders, but findings regarding eating disorders are inconsistent and inconclusive. This total-population Swedish cohort study identified 2,015,862 individuals born in 1975-1998 and followed them for anorexia nervosa, bulimia nervosa, and eating disorder not otherwise specified until the end of 2010. We examined associations with multiple family and birth characteristics and conducted within-family analyses to test for maternal-level confounding. In total, 1,019 males and 15,395 females received an eating disorder diagnosis. Anorexia nervosa was independently predicted by multiple birth (adjusted hazard ratio = 1.33, 95% confidence interval: 1.15, 1.53) for twins or triplets vs. singletons) and lower gestational age (adjusted hazard ratio = 0.96, 95% confidence interval: 0.95, 0.98) per extra week of gestation, with a clear dose-response pattern. Within-family analyses provided no evidence of residual maternal-level confounding. Higher birth weight for gestational age showed a strong, positive dose-response association with bulimia nervosa (adjusted hazard ratio = 1.15, 95% confidence interval: 1.09, 1.22, per each standard-deviation increase), again with no evidence of residual maternal-level confounding. We conclude that some perinatal characteristics may play causal, disease-specific roles in the development of eating disorders, including via perinatal variation within the normal range. Further research into the underlying mechanisms is warranted. Finally, several large population-based studies of anorexia nervosa have been conducted in twins; it is possible that these studies considerably overestimate prevalence.

A systematic review of obstetric complications as risk factors for eating disorder and a meta-analysis of delivery method and prematurity

OBJECTIVE

The aim of this study was to systematically review the literature on obstetric factors at birth and their role as risk factors for a subsequent eating disorder (ED) and where possible to perform a meta-analysis of case-control studies of EDs and obstetric complications (OCs).

METHOD

Studies were ascertained by computer searches of electronic databases (Medline, PsycINFO, Web of Science and CINAHL), searches of reference lists and from raw data obtained upon request from the authors. A total of 14 studies were identified for the systematic review, of which 6 were eligible for the subsequent meta-analysis. Of the selected 6 studies, 5 reported on the same OCs, namely vaginal instrumental delivery and prematurity. Accordingly, meta-analyses were run on these two variables. Both analyses were conducted on anorexia nervosa (AN) patients.

RESULTS

Findings from the systematic review were conflicting, with some studies reporting a significant relationship between OCs and ED diagnoses and/or ED symptomatology and others refuting it. A non-significant association of instrumental delivery [pooled odds ratio (OR) 1.06, 95%CI: 0.69, 1.65] and prematurity [pooled OR 1.17, 95%CI: 0.91, 1.52] with AN was revealed in our meta-analysis.

CONCLUSION

The current literature on OCs as risk factors for a later ED is contradictory. The range of different occurrences considered as OCs and methodological limitations hinder ultimate conclusions. Upcoming studies should pool datasets together to obtain sufficient power to assess OCs and EDs in combination.

Clinical and temperamental correlates of body image disturbance in eating disorders

OBJECTIVE

Although body image disturbance (BID) is considered a core symptom in anorexia nervosa (AN) and bulimia nervosa (BN), little is known about its psychopathological correlates. The present study aimed at analysing the correlation of aspects of BID with psychopathological and temperamental characteristics.

METHOD

A sample of 1288 patients (538 AN and 750 BN) were assessed through a structured diagnostic interview, the Eating Disorders Inventory and Tridimensional Personality Questionnaire. Cognition of body image distortion, weight checking, fear of weight gain and body dissatisfaction were assessed by specific questions during the interview.

RESULTS

Various aspects of BID formed similar, but not identical, dimensions in AN and BN. In both groups, anticipatory anxiety and interoceptive awareness were significantly and independently associated with body image distortion, whereas ineffectiveness was associated with weight checking.

DISCUSSION

Body image disturbance is a multidimensional characteristic linked to psychological features, such as anticipatory anxiety, ineffectiveness and interoceptive awareness. These findings have scientific and treatment implications, and should be considered by clinicians in adopting successful treatment strategies.

A meta-analysis of temperament in axis I psychiatric disorders

This article reports on a meta-analysis of Cloninger's temperament dimensions (novelty seeking, harm avoidance, reward dependence, and persistence) in individuals with lifetime psychiatric disorders compared with controls and on interdisorder comparisons between these disorders. Nine disorders from 75 studies were included in the meta-analyses. The most consistent feature was elevated harm avoidance: compared with the controls, harm avoidance was higher in all diagnostic groups studied except for those with alcohol use disorders. The increase in effect sizes in harm avoidance scores varied from a very large (d = 2.66) in social phobia to a small effect (effect size, d = 0.29) in alcohol use disorders. In other dimensions, differences between cases and controls were relatively small. However, in pairwise comparisons, notable differences also in other dimensions emerged: in novelty seeking, the lowest scores were in social phobia (d = -0.87) and the highest in bulimia nervosa (d = 0.33); in reward dependence, the lowest scores were in schizophrenia (d = -0.36) and the highest in social phobia (d = 0.12); and in persistence, the lowest scores were in social phobia (d = -0.30) and the highest in anorexia nervosa (d = 0.49). The provided data should be taken into account in the future studies on suggestive vulnerability markers for psychiatric morbidity.

In utero exposure to virus infections and the risk of developing anorexia nervosa

BACKGROUND

The study aims to explore, using indirect ecological measures of exposure, the role of viral infections in the development of anorexia nervosa (AN).

METHOD

The cohort of participants consisted of all female subjects born in the Veneto region in the period between 1970 and 1984, and residing in the urban and suburban area of Padua (27,682 female subjects in an area of 424 km2). The main outcome measure was the diagnosis of AN resulting from the Public Mental Health Database, the Register of Hospital Admissions, and the Register of the Eating Disorders Unit (n=402, 1.4%). The number of cases of rubella, chickenpox, influenza and measles was ascertained for each month for the 15-year period.

RESULTS

Exposures during the sixth month of pregnancy to the peaks of chickenpox [odds ratio (OR) 1.6, 95% confidence interval (CI) 1.2-2.0] and rubella infections (OR 1.5, 95% CI 1.1-2.0) were significantly associated with an increased risk of developing AN, even after controlling for socio-economic status, urbanization and month of birth. We found weak evidence of a season-of-birth bias.

CONCLUSIONS

In utero exposure to viral infection could be a risk factor for developing AN. We need further epidemiological and serological studies to confirm this hypothesis.

Perinatal complications in unaffected sisters of anorexia nervosa patients: testing a covariation model between genetic and environmental factors

Although perinatal complications are hypothesized to be risk factors for the development of anorexia nervosa (AN), no study to date explored this issue using a discordant sibling design. This type of design allows to explore whether the risk for obstetric complications is itself a consequence of the genetic vulnerability for AN (covariation model) or whether obstetric complications increase the risk of AN independently of (additive model), or in interaction with (interaction model), the disorder's genetic liability. The presence of perinatal complications was assessed through review of the obstetric records of 60 AN subjects, 60 unaffected sisters, and 70 healthy subjects. Unaffected sisters and healthy controls were compared in relation to perinatal characteristics and complications. There was no evidence for an elevated rate of complications in unaffected siblings of AN patients. Mothers with a positive psychiatric history tended to have more perinatal complications. Perinatal complications seem to be independent risk factors that may interact with, but are not caused by, familial risk factors for AN. In terms of prevention, a particular attention should be paid to mothers with a lifetime history of psychiatric disorders.

Mediation analysis in psychosomatic medicine research

This article presents an overview of statistical mediation analysis and its application to psychosomatic medicine research. The article begins with a description of the major approaches to mediation analysis and an evaluation of the strengths and limits of each. Emphasis is placed on longitudinal mediation models, and an application using latent growth modeling is presented. The article concludes with a description of recent developments in mediation analysis and suggestions for the use of mediation for future work in psychosomatic medicine research.

Reduced body size and shape-related symptoms in young adults born preterm with very low birth weight: Helsinki study of very low birth weight adults

OBJECTIVE

To test the hypothesis that being born prematurely with very low birth weight (VLBW) (birth weight<or=1500 g) is associated with subphenotypes of eating disorders (dissatisfaction with body shape and pursuit of thinness) in young adulthood.

STUDY DESIGN

Preterm-born VLBW subjects (n=163) and controls (n=189) born at term completed 3 subscales of Eating Disorder Inventory-2 questionnaire (EDI): Drive for Thinness, Body Dissatisfaction, and Bulimia. Data were analyzed with multiple linear regression adjusted for confounders.

RESULTS

Among both sexes, EDI total scores were lower in VLBW subjects than in controls. The fully adjusted difference was -11.0% (95% CI, -18.4%, -2.2%) for women and -11.2% (95% CI, -20.2%, -1.3%) for men. Among women the lower scores in VLBW adults were observed in each EDI subscale. Results were similar when adjusted also for fat percentage, measured by dual-energy x-ray absorptiometry. Of the covariates, higher body mass index and higher score in Beck Depression Inventory contributed significantly to a higher EDI total score.

CONCLUSIONS

Young adults, particularly women, born prematurely with VLBW have fewer body size and shape-related symptoms and possibly lower risk for eating disorders than their term-born peers.

Sensitivity to reward and punishment in eating disorders

The aim of this review was to collate and summarise the self-report data regarding anomalies in sensitivity to reward and punishment in eating disorders (ED) with use of a meta-analysis where possible. Electronic databases were searched to December 2008. Studies were required to have a non-eating disorder healthy control group and include at least one self-report measure of sensitivity to reward or punishment in an eating disorder population. Findings were very heterogeneous and inconsistencies between studies and measures were highlighted. In general, patients with anorexia nervosa (restricting type) were less sensitive to reward than healthy controls, whereas patients with bulimia nervosa and anorexia nervosa (binge/purge) type were more sensitive. All ED groups report higher sensitivity to punishment than healthy controls. Individuals with eating disorders differ from healthy controls in measures of reward and punishment sensitivity as measured using the Temperament and Character Inventory, Tridimensional Personality Questionnaire and BIS/BAS scales, but further work is required as there is some heterogeneity in the data. Generating more research using behavioural measures may increase understanding of the findings.

The interaction between perinatal factors and childhood abuse in the risk of developing anorexia nervosa

BACKGROUND

Perinatal factors seem to be implicated in the pathogenesis of anorexia nervosa (AN) and may be involved in the programming of stress response systems in humans. Our aim was to explore one of the possible pathways to explain the association between perinatal complications and a psychiatric disorder. In particular, we tested the hypothesis that neonatal immaturity may confer an enhanced vulnerability to AN after exposure to a severe stressful event, such as childhood abuse.

METHOD

The sample was composed of subjects who took part in a prevalence study carried out on a representative sample of the general population and cases of AN referred to an out-patient specialist unit. All subjects (n=663) were born in the two obstetric wards of Padua Hospital between 1971 and 1979. We analysed data using both a case-control and a cohort design.

RESULTS

We found that functional signs of neonatal dysmaturity, but not a low birthweight or prematurity, had a significant additive interaction with childhood abuse in determining the risk for this illness. In normal subjects, but not in subjects with AN, neonatal dysmaturity was associated with being small, short or thin for gestational age at birth.

CONCLUSIONS

The synergistic effect of neonatal dysmaturity and childhood abuse in increasing the risk for AN provides evidence for the hypothesis that a prenatal programming of stress response systems can result in an impairment of the individual's resilience to severe stressful events.

Personality and temperament

The assessment of personality and temperament in the context of eating disorders (EDs) poses unique challenges because of the physiological symptoms and sequelae of these illnesses. Four models of the relationship between personality and EDs are presented, along with a discussion of the different methodological designs which can evaluate these models. Current data support the likelihood that neuroticism and perfectionism are risk factors for EDs. Perfectionism and the related obsessive-compulsive personality disorder may also share a common cause with anorexia nervosa. High harm avoidance and low self-directedness also characterize all EDs, though more data are needed to confirm their role as risk factors; importantly however, this combination of traits may diminish one's ability to cope with stressful life events. At the other end of the spectrum, considering impulsivity multidimensionally may be important to understanding the role of this personality trait in EDs, though existing data do not yet allow for conclusions regarding its role as a risk factor versus a consequence of the ED. All of the identified traits that may be risk factors are also exacerbated as a consequence of having, or having had, an ED. Finally, the role of personality disorders in influencing the course and outcome of EDs is still unclear. A fruitful avenue for future research in this area is to utilize personality and temperament to classify individuals in a way that allows for the best chance of identifying genetic loci that confer increased risk for EDs.