Association between neuroendocrinological parameters and learning and memory functions in adolescent anorexia nervosa before and after weight recovery

Associations between pituitary-thyroid hormones and depressive symptoms in individuals with anorexia nervosa before and after weight-recovery

BACKGROUND

There is sound evidence that the hypothalamic-pituitary-thyroid axis plays a role in mood regulation. Alterations in this axis, particularly low triiodothyronine syndrome, are a common neuroendocrine adaptation to semi-starvation in patients with anorexia nervosa (AN), who also frequently suffer from co-existing depressive symptoms. We therefore aimed to investigate the associations between pituitary-thyroid function and psychopathology, in particular depressive symptoms, at different stages of AN using a combined cross-sectional and longitudinal study design.

METHODS

Pituitary-thyroid status (FT3, free triiodothyronine; FT4, free thyroxine; conversion ratio FT3/FT4; TSH, thyroid-stimulating hormone) was assessed in 77 young acutely underweight females with AN (acAN) and in 55 long-term weight-recovered individuals with former AN (recAN) in a cross-sectional comparison to 122 healthy controls (HC). Further, pituitary-thyroid status of 48 acAN was reassessed after short-term weight-restoration. We performed correlation analyses of pituitary-thyroid parameters with self-reported measures of psychopathology.

RESULTS

AcAN showed significantly lower FT3, FT4, FT3/FT4 ratio, and TSH levels compared to HC. Pituitary-thyroid alterations were partly reversed after short-term weight-restoration. RecAN still had lower FT3 concentrations than HC. Lower FT3 concentrations and FT3/FT4 ratios were associated with more severe depressive symptoms in acAN, occurring prominently in cases of manifest low triiodothyronine syndrome. Longitudinally increasing FT3/FT4 ratios (change scores) were inversely correlated with depressive and general psychiatric symptoms after short-term weight-restoration.

CONCLUSIONS

Our results suggest a potential modulation of the severity of depressive symptoms by temporarily decreased FT3 concentrations and inhibited thyroid hormone conversion (FT3/FT4 ratios) in acutely underweight AN. Associations between conversion ratios FT3/FT4 and psychopathology seem to persist across short-term weight-restoration. The findings of our study might have relevant clinical implications, ranging from thyroid monitoring to experimental low-dose thyroid hormone supplementation in certain patients with AN showing severe psychiatric impairment and overt thyroid hormone alterations.

The Role of Glial Cells in Regulating Feeding Behavior: Potential Relevance to Anorexia Nervosa

Eating behavior is controlled by hypothalamic circuits in which agouti-related peptide-expressing neurons when activated in the arcuate nucleus, promote food intake while pro-opiomelanocortin-producing neurons promote satiety. The respective neurotransmitters signal to other parts of the hypothalamus such as the paraventricular nucleus as well as several extra-hypothalamic brain regions to orchestrate eating behavior. This complex process of food intake may be influenced by glia cells, in particular astrocytes and microglia. Recent studies showed that GFAP⁺ astrocyte cell density is reduced in the central nervous system of an experimental anorexia nervosa model. Anorexia nervosa is an eating disorder that causes, among the well-known somatic symptoms, brain volume loss which was associated with neuropsychological deficits while the underlying pathophysiology is unknown. In this review article, we summarize the findings of glia cells in anorexia nervosa animal models and try to deduce which role glia cells might play in the pathophysiology of eating disorders, including anorexia nervosa. A better understanding of glia cell function in the regulation of food intake and eating behavior might lead to the identification of new drug targets.

The Association of Malnutrition, illness duration, and pre-morbid weight status with anxiety and depression symptoms in adolescents and young adults with restrictive eating disorders: a cross-sectional study

BACKGROUND

Restrictive eating disorders (EDs) are often comorbid with anxiety and depression symptoms, placing patients at risk for more severe disease, worse treatment outcomes, and higher rates of mortality. To identify risks for developing such co-morbidities, we assessed the association of malnutrition, ED illness duration, and pre-morbid weight status with symptoms of anxiety and depression in adolescents/young adults (AYAs) with EDs.

METHODS

145 participants with restrictive EDs (anorexia nervosa [AN], other specified feeding and eating disorders [OSFED], avoidant restrictive food intake disorder [ARFID]) were included from the RECOVERY study, a longitudinal web-based registry of AYAs with EDs. We measured malnutrition as percent of expected body mass index (%eBMI), based on participants' pre-morbid growth trajectory. Outcomes were anxiety and depression scores from the Generalized Anxiety Disorder 7-item (GAD-7) and Center for Epidemiologic Studies Depression (CES-D) scales. We used multiple linear regression to examine the association of malnutrition, ED duration, and pre-morbid weight status with symptoms of anxiety and depression.

RESULTS

Mean (SD) age was 16.4(3.0) years; 87% were female; 89% white; 85% had AN, 6% OSFED, 10% ARFID. Of these, 2/3 had ED symptoms ≥1 year, 1/3 had previous higher level of ED care (HLOC), and half were taking psychiatric medications. Mean %eBMI was 90% (range 57-112%). Mean GAD-7 was 9.4(5.9) and CES-D was 24(13.8), indicating most participants had clinically significant anxiety and/or depression. Degree of malnutrition was not significantly associated with anxiety or depression adjusting for age, sex, sexual orientation, ED diagnosis, and use of psychiatric medication. Those with longer duration of ED symptoms had higher depression scores after adjusting for malnutrition, HLOC, length of ED symptoms, and time in our care (p = 0.038). Patients with pre-morbid BMIs ≥75th percentile had lower depression scores than those with pre-morbid BMIs <75th percentile (p = 0.014).

CONCLUSIONS

We find high degree of clinically relevant anxiety and depression symptoms in a population of AYAs with EDs. Our findings suggest that factors beyond malnutrition play a role in the co-morbid mood and anxiety disorders in this population. Overall, rapid ED diagnosis and comprehensive treatment for patients with EDs across the weight spectrum-and especially those with psychiatric co-morbidities-will likely aid in recovery.

Long-Term Glucose Starvation Induces Inflammatory Responses and Phenotype Switch in Primary Cortical Rat Astrocytes

Astrocytes are the most abundant cell type in the brain and crucial to ensure the metabolic supply of neurons and their synapse formation. Overnutrition as present in patients suffering from obesity causes astrogliosis in the hypothalamus. Other diseases accompanied by malnutrition appear to have an impact on the brain and astrocyte function. In the eating disorder anorexia nervosa (AN), patients suffer from undernutrition and develop volume reductions of the cerebral cortex, associated with reduced astrocyte proliferation and cell count. Although an effect on astrocytes and their function has already been shown for overnutrition, their role in long-term undernutrition remains unclear. The present study used primary rat cerebral cortex astrocytes to investigate their response to chronic glucose starvation. Cells were grown with a medium containing a reduced glucose concentration (2 mM) for 15 days. Long-term glucose starvation increased the expression of a subset of pro-inflammatory genes and shifted the primary astrocyte population to the pro-inflammatory A1-like phenotype. Moreover, genes encoding for proteins involved in the unfolded protein response were elevated. Our findings demonstrate that astrocytes under chronic glucose starvation respond with an inflammatory reaction. With respect to the multiple functions of astrocytes, an association between elevated inflammatory responses due to chronic starvation and alterations found in the brain of patients suffering from undernutrition seems possible.

Cognitive improvement following weight gain in patients with anorexia nervosa: A systematic review

OBJECTIVE

Anorexia nervosa (AN) has been associated with cognitive impairment. While re-nutrition is one of the main treatment targets, the effect on cognitive impairments is unclear. The aim of this review was to examine whether cognitive functions improve after weight gain in patients with AN.

METHOD

A systematic review was performed following Preferred Reporting Items for Systematic Reviews and Meta-analyses statement guidelines (PROSPERO CRD42019081993). Literature searches were conducted May 20^th , 2019 in PubMed, EMBASE, PsychINFO and Cochrane Library. Pairs of reviewers screened reports independently based on titles/abstracts (N = 6539) and full texts (N = 378). Furthermore, they assessed the quality of reports, including whether practice effects were accounted for.

RESULTS

Twenty-four longitudinal reports were included featuring 757 patients and 419 healthy controls. Six studies examined children and adolescents. Four out of four studies found processing speed to improve above and beyond what could be assigned to practice effects and three out of four studies found that cognitive flexibility was unaffected after weight gain in children and adolescents. Results from studies of adults were inconclusive.

DISCUSSION

The literature on cognitive change in patients with AN following weight gain is sparse. Preliminary conclusions can be made only for children and adolescents, where weight gain appeared to be associated with improved processing speed.

Cortisol reactivity in patients with anorexia nervosa after stress induction

There is a need of experimental studies on biomarkers in patients with anorexia nervosa (P_AN), especially in the context of stress, in order to foster understanding in illness maintenance. To this end, the cortisol response to an acute stressor was investigated in n = 26 P_AN (BMI: 19.3 ± 3.4 kg/m²), age, and gender matched to n = 26 healthy controls (HC; BMI: 23.08 ± 3.3 kg/m²). For this purpose, salivary cortisol parameters were assessed in two experimental conditions: (1) rest/no intervention and (2) stress intervention (TSST; Trier Social Stress Test). In addition, psychological indicators of stress were assessed (Primary Appraisal Secondary Appraisal, Visual Analogue Scale, and Trier Inventory for the assessment of Chronic Stress), as well as psychological distress, depression, and eating disorder (ED) symptoms. A 2 × 2 × 8 ANOVA demonstrated elevated cortisol levels in P_AN in the resting condition. In the stress intervention no significant group effect in terms of cortisol (F (1, 50) = 0.69; p = 0.410; [Formula: see text]). A significant condition (F (1, 50) = 20.50; p = 0.000; [Formula: see text]) and time effect (F(2.71, 135.44) = 11.27; p = 0.000; [Formula: see text]) were revealed, as well as two significant interaction effects. First: Condition × group (F (1, 50) = 4.17, p = 0.046; [Formula: see text]) and second: Condition × time (F (2.71, 135.44) = 16.07, p = 0.000, [Formula: see text]). In terms of AUC_G, no significant differences between both groups were exhibited. Regardless, significant results were evinced in terms of an increase (AUC_i: F(1, 50) = 20.66, p = 0.015, [Formula: see text]), baseline to peak (+20 min post-TSST: t₅ = 16.51 (9.02), p = 0.029) and reactivity (M_PAN = 0.73 vs. M_HC = 4.25, p = 0.036). In addition, a significant correlation between AUC_G and BMI: r (24) = -0.42, p = 0.027 was demonstrated, but not between AUC_i and BMI (r (24) = -0.26, p = 0.20). Psychological indices suggested higher levels of chronic and perceived stress in P_AN relative to HC. However, stress perception in the stress condition (VAS) was comparable. Additional analyses demonstrated that ED-symptoms are highly correlated with psychological distress and depression, but not with BMI. In addition, it could be demonstrated that reactivity is rather related to ED-symptoms and psychological burden than to BMI. In conclusion, P_AN showed elevated basal cortisol levels at rest and exhibited a blunted cortisol reactivity to the TSST as evinced by salivary cortisol parameters. Further, it was shown that weight recovery influences reversibility of hypercortisolemia, i.e., cortisol levels normalize with weight gain. However, HPAA (hypothalamus-pituitary-adrenal axis) irregularities in terms of reactivity persist even at a BMI ≤ 19.3 (±3.4). Our data suggest that pronounced psychological burden in P_AN, have a greater impact on the HPAA functionality (secondary to the ED) than BMI itself.

Changes of BMI, steroid metabolome and psychopathology in patients with anorexia nervosa during hospitalization

Anorexia nervosa (AN) is associated with various alterations including the dysfunction of the HPA axis and consequently the hypercortisolemia and deficit in sex hormones but the comprehensive evaluation of changes in circulating steroids during the hospitalization of AN patients is lacking. We investigated the effect of realimentation of women with AN during hospitalization on 45 circulating steroids, the relationships between BMI, its change during hospitalization and physical activity, on one side and initial levels and their changes for two adipokines, circulating steroids, anorexia-specific (hunger, appetite and satiety), and anorexia non-specific symptoms (anxiety, depression fatigue, sleep, and body pain) on the other side. We included 33 women with anorexia who were hospitalized for 38(35, 44) days (median with quartiles). The increase of BMI from the initial value 15.2 (13.2, 16.6) kg/m² was 1.69 (1.37, 2.66) kg/m². The patients with more severe anorexia showed higher activity in 7β-, and 16α-hydroxylation of androgen precursors, which declined during hospitalization. Otherwise, the 7α-hydroxylation activity is higher in AN patients with less severe malnutrition and the ratio of 5-androstene-3β,7α,17β-triol to 5-androstene-3β,7β,17β-triol increased during the realimentation. Our data allow to speculate that the intensive 7β-, and 16α- and possibly also the 7α-hydroxylation of C19 Δ⁵ steroids participate in the pathophysiology of anorexia by additional catabolism of substrates available for synthesis of active androgens and estrogens. However, the question remains whether the synthetic analogues of 7α/β- and 16α-hydroxy-steroids prevent the catabolism of the sex steroid precursors, or further activate the "energy wasting" mitochondrial thermogenic metabolism.

Associations between neuropsychological performance and appetite-regulating hormones in anorexia nervosa and healthy controls: Ghrelin's putative role as a mediator of decision-making

Anorexia nervosa (AN) is a severe eating disorder accompanied by alterations in endocrinological circuits and deficits in neuropsychological performance. In this study, a series of appetite-regulating hormones (ghrelin, leptin, cholecystokinin, PYY, adiponectin, and visfatin) were measured under fasting conditions in female patients with AN and female healthy controls. All of the participants also underwent a battery of neuropsychological assessment [namely the Iowa Gambling Task (IGT), the Wisconsin Card Sorting Test (WCST), and the Stroop Color and Word Test (SCWT)]. As the main finding, we found that higher ghrelin levels predict better performance in the IGT. Ghrelin may be a putative mediator of decision-making, a finding that has not been described so far. The role of ghrelin in decision-making can only be described as speculative, as there are hardly any additional evidence-based data published up to date. Further studies are warranted.

Residual eating disorder symptoms and clinical features in remitted and recovered eating disorder patients: A systematic review with meta-analysis

OBJECTIVE

In psychiatry, the presence of residual symptoms after treatment is linked to the definitions of remission and recovery. To identify the presence of residual eating disorder (ED) symptoms and associated non-ED clinical features in remitted and recovered EDs, the current systematic review with meta-analysis was performed.

METHOD

A systematic review was conducted on residual ED symptoms and non-ED clinical features including comorbid psychopathology, neurophysiological functioning, cognitive functioning, and quality of life in ED patients considered remitted or recovered. To examine residual ED symptoms, meta-analyses were performed while considering age, study quality, remission, and recovery criteria strictness as moderators. Sensitivity, publication bias, and heterogeneity analyses were also conducted.

RESULTS

The 64 studies selected for the systematic review underscored the presence of residual ED symptoms in anorexia nervosa (AN) and bulimia nervosa (BN), and impairments and deficits in the additional features examined. From the 64 studies, 31 were selected regarding residual ED symptoms in AN for meta-analysis. Large effect sizes indicated that remitted/recovered AN patients reported significantly lower body mass index (Hedges' g = -0.62[-0.77, -0.46]) and significantly greater symptomatology in terms of ED examination-questionnaire (Hedges'g = 0.86 [0.48,1.23]) and ED inventory (Hedges' g = 0.94[0.64,1.24]) than healthy controls, independently of remission and recovery criteria strictness, age, and study quality.

DISCUSSION

The presence of residual ED symptoms in AN is quantitatively supported, whereas the presence of residual ED symptoms in BN should be further investigated. Data on binge-eating disorder are missing. Future research should use consistent, multicomponent, and standardized comparable indicators of recovery.

The reduction of astrocytes and brain volume loss in anorexia nervosa-the impact of starvation and refeeding in a rodent model

Anorexia nervosa (AN) is an often chronic, difficult to treat illness that leads to brain volume reductions in gray and white matter. The underlying pathophysiology is poorly understood, despite its potential importance in explaining the neuropsychological deficits and clinical symptoms associated with the illness. We used the activity-based anorexia model (ABA), which includes food reduction and running wheel access in female rats to study brain changes after starvation and refeeding. Longitudinal animal MRI and post-mortem brain sections confirmed a reduction in the mean brain volumes of ABA animals compared to controls. In addition, the mean number of astrocytes was reduced by over 50% in the cerebral cortex and corpus callosum, while the mean number of neurons was unchanged. Furthermore, mean astrocytic GFAP mRNA expression was similarly reduced in the ABA animals, as was the mean cell proliferation rate, whereas the mean apoptosis rate did not increase. After refeeding, the starvation-induced effects were almost completely reversed. The observation of the astrocyte reduction in our AN animal model is an important new finding that could help explain starvation-induced neuropsychological changes in patients with AN. Astrocyte-targeted research and interventions could become a new focus for both AN research and therapy.

The association of leptin secretion with cognitive performance in patients with eating disorders

This study is an investigation of neuropsychological performance in patients with anorexia nervosa, bulimia nervosa, and binge eating disorder and hormonal secretion patterns for ghrelin, leptin, insulin, and glucose. An oral glucose tolerance test (OGTT) was performed in a cohort of n = 30 female patients suffering from eating disorders as well as n = 20 control females. All participants underwent the Wisconsin Card Sorting Test (WCST), the Trail Making Test (TMT), and a go/no-go task using food vs. neutral stimuli. Patients with anorexia nervosa differed from controls in their leptin response to the OGTT. While the four groups under investigation did not differ in neuropsychological performance, we found leptin responses to the OGTT to be associated with performance in the food-specific go/no-go task. These preliminary results may indicate a putative association between leptin concentrations and neuropsychological performance, particularly in measures of inhibitory control. Further studies investigating the role of leptin in impulsive behaviors in eating disorders would be useful.

Differences in cortisol concentrations in adolescents with eating disorders: a systematic review

OBJECTIVE

To perform a systematic review of the literature for scientific evidence of possible differences in cortisol concentrations in adolescents with eating disorders.

SOURCE OF DATA

Electronic searches were conducting in the PubMed, Scientific Electronic Library Online, Virtual Health Library, and Science Direct databases for articles published between 2007 and 2017 using the keywords, cortisol, hydrocortisone; eating disorders, bulimia, bulimia nervosa, anorexia, anorexia nervosa; adolescence, adolescent, adolescents.

SYNTHESIS OF DATA

A total of 192 articles were found. After the analysis of the eligibility criteria using the PRISMA method, 19 articles were selected for the present review. Most studies were conducted in Europe. Adolescents diagnosed with anorexia nervosa were evaluated in all studies, except one, when other eating disorders were investigated. Blood was the means used for the determination of cortisol. In ten studies, cortisol levels were higher in the group with anorexia than the control group and a reduction in cortisol levels occurred in the adolescents after being submitted to nutritional recovery.

CONCLUSIONS

Patients with eating disorders may have several clinical consequences, such as changes in body fat distribution, changes in bone mineral density, worsening of neurocognitive ability, and endocrine changes (e.g., hypercortisolemia), which in turn can lead to hyperglycemia, insulin resistance, hypertension, and increased risk of infections. The findings demonstrate that adolescents with eating disorders, especially anorexia nervosa, have increased cortisol levels, which are reduced after the treatment period. Further studies on differences in cortisol concentrations in adolescents with other eating disorders are needed, using different methods.

Exploration of Shared Genetic Architecture Between Subcortical Brain Volumes and Anorexia Nervosa

In MRI scans of patients with anorexia nervosa (AN), reductions in brain volume are often apparent. However, it is unknown whether such brain abnormalities are influenced by genetic determinants that partially overlap with those underlying AN. Here, we used a battery of methods (LD score regression, genetic risk scores, sign test, SNP effect concordance analysis, and Mendelian randomization) to investigate the genetic covariation between subcortical brain volumes and risk for AN based on summary measures retrieved from genome-wide association studies of regional brain volumes (ENIGMA consortium, n = 13,170) and genetic risk for AN (PGC-ED consortium, n = 14,477). Genetic correlations ranged from − 0.10 to 0.23 (all p > 0.05). There were some signs of an inverse concordance between greater thalamus volume and risk for AN (permuted p = 0.009, 95% CI: [0.005, 0.017]). A genetic variant in the vicinity of ZW10, a gene involved in cell division, and neurotransmitter and immune system relevant genes, in particular DRD2, was significantly associated with AN only after conditioning on its association with caudate volume (p_FDR = 0.025). Another genetic variant linked to LRRC4C, important in axonal and synaptic development, reached significance after conditioning on hippocampal volume (p_FDR = 0.021). In this comprehensive set of analyses and based on the largest available sample sizes to date, there was weak evidence for associations between risk for AN and risk for abnormal subcortical brain volumes at a global level (that is, common variant genetic architecture), but suggestive evidence for effects of single genetic markers. Highly powered multimodal brain- and disorder-related genome-wide studies are needed to further dissect the shared genetic influences on brain structure and risk for AN.

Prospective, randomized, double-blind, placebo-controlled phase IIa clinical trial on the effects of an estrogen-progestin combination as add-on to inpatient psychotherapy in adult female patients suffering from anorexia nervosa

BACKGROUND

There is a need for novel treatment approaches in anorexia nervosa (AN). While there is broad knowledge with regard to altered appetite regulation and neuropsychological deficits in AN patients on the one hand, and the effects of estrogen replacement upon neuropsychological performance in healthy subjects on the other, up to now, no study has implemented estrogen replacement in AN patients, in order to examine its effects upon AN-associated and general psychopathology, neuropsychological performance and concentrations of peptide components of the hypothalamus-pituitary-adrenal (HPA) axis and within appetite-regulating circuits.

METHODS

This is a randomized placebo-controlled clinical trial on the effects of a 10-week oral estrogen replacement (combination of ethinyl estradiol 0.03 mg and dienogest 2 mg) in adult female AN patients. The primary target is the assessment of the impact of sex hormone replacement upon neuropsychological performance by means of a neuropsychological test battery consisting of a test for verbal intelligence, the Trail making test A and B, a Go/No-go paradigm with food cues and the Wisconsin Card Sorting Test. Secondary targets include a) the examination of safety and tolerability (as mirrored by the number of adverse events), b) assessments of the impact upon eating disorder-specific psychopathology by means of the Eating Disorder Examination Questionnaire (EDE-Q) and the Eating Disorder Inventory-2 (EDI-2), c) the influence upon anxiety using the State-Trait-Anxiety Inventory (STAI), d) assessments of plasma cortisol levels during a dexamethasone-suppression test and appetite-regulating plasma peptides (ghrelin, leptin, insulin, glucose) during an oral glucose tolerance test and, e) a possible impact upon the prescription of antidepressants.

DISCUSSION

This is the first study of its kind. There are no evidence-based psychopharmacological options for the treatment of AN. Thus, the results of this clinical trial may have a relevant impact on future treatment regimens. Novel approaches are necessary to improve rates of AN symptom remission and increase the rapidity of treatment response. Identifying the underlying biological (e.g. neuroendocrinological) factors that maintain AN or may predict patient treatment response represent critical future research directions. Continued efforts to incorporate novel pharmacological aspects into treatments will increase access to evidence-based care and help reduce the burden of AN.

TRIAL REGISTRATION

European Clinical Trials Database, EudraCT number 2015-004184-36, registered November 2015; ClinicalTrials.gov Identifier: NCT03172533 , retrospectively registered May 2017.

Reduced astrocyte density underlying brain volume reduction in activity-based anorexia rats

OBJECTIVES

Severe grey and white matter volume reductions were found in patients with anorexia nervosa (AN) that were linked to neuropsychological deficits while their underlying pathophysiology remains unclear. For the first time, we analysed the cellular basis of brain volume changes in an animal model (activity-based anorexia, ABA).

METHODS

Female rats had 24 h/day running wheel access and received reduced food intake until a 25% weight reduction was reached and maintained for 2 weeks.

RESULTS

In ABA rats, the volumes of the cerebral cortex and corpus callosum were significantly reduced compared to controls by 6% and 9%, respectively. The number of GFAP-positive astrocytes in these regions decreased by 39% and 23%, total astrocyte-covered area by 83% and 63%. In neurons no changes were observed. The findings were complemented by a 60% and 49% reduction in astrocyte (GFAP) mRNA expression.

CONCLUSIONS

Volumetric brain changes in ABA animals mirror those in human AN patients. These alterations are associated with a reduction of GFAP-positive astrocytes as well as GFAP expression. Reduced astrocyte functioning could help explain neuronal dysfunctions leading to symptoms of rigidity and impaired learning. Astrocyte loss could constitute a new research target for understanding and treating semi-starvation and AN.

Extend, Pathomechanism and Clinical Consequences of Brain Volume Changes in Anorexia Nervosa

INTRODUCTION

Brain volume deficits of grey matter (GM) and white matter (WM) are often found in patients with anorexia nervosa (AN). However, until recently, little was known about the influencing factors of these brain volume alterations, nor their exact quantification and rehabilitation.

METHODS

This review addresses these open questions and further explores what is now known about the underlying pathobiology and the clinical consequences including human studies as well as animal studies mimicking anorexia nervosa in rodents.

RESULTS

GM was reduced by 3.7% in adults and 7.6% in adolescents with AN. WM was reduced on average 2.2% in adult patients and 3.2% in adolescents. Most volume deficits in adults are reversible after long-term recovery; for adolescents, data are less clear. The main influencing factors for GM were absolute lowest weight at admission and illness duration. Cerebellar and WM reductions at admission predicted clinical outcome at one year follow-up. New studies found GABA receptor changes in GM and astrocyte loss in both GM and WM, as well as a possible role for oestrogen deficit. All three could partly explain clinical symptoms of anxiety, rigidity and learning impairments in patients with AN.

CONCLUSION

Brain volume deficits in AN seem to play a causal role in the course and the prognosis of AN. A better understanding of these brain changes could lead to more targeted therapies for patients with AN, including astrocyte-directed approaches.

Establishment of a chronic activity-based anorexia rat model

BACKGROUND

Anorexia nervosa (AN) is often a chronic eating disorder characterised by body image disturbance and low body weight often associated with starvation-induced amenorrhoea and excessive exercise. Activity-based anorexia (ABA) is an animal model representing many somatic aspects of this psychiatric illness. We systematically manipulated the extent and length of starvation and animal age to find the optimal parameters to study chronic starvation.

NEW METHODS

Wistar rats had 24h/day running wheel access and received 40% of their baseline food intake until a 20% or 25% weight reduction was reached (acute starvation). This body weight was then maintained for two weeks (chronic starvation). The rats of different ages of 4 or 8 weeks were used to represent early and late adolescent animals, respectively. The complete absence of a menstrual cycle was defined as the primary outcome parameter.

RESULTS

Acute starvation caused a disruption of the oestrous cycle in 58% of the animals. During chronic starvation, a complete loss of the oestrous cycle could be found. Furthermore, 4-week-old rats exhibited higher levels of hyperactivity and amenorrhoea than 8-week-old animals. A 20% starvation level led to 90% loss of cycle, while a 25% starvation level triggered complete loss.

COMPARISON WITH EXISTING METHODS

Most current ABA models focus on acute starvation, while most patients are chronically ill.

CONCLUSIONS

The optimal parameters to achieve complete amenorrhoea included early adolescence, chronic starvation and 25% weight loss. The new ABA model allows studying the effects of chronic AN on underlying behavioural, hormonal and brain pathobiology.

Cognitive Flexibility in Juvenile Anorexia Nervosain Relation to Comorbid Symptoms of Depression, Obsessive Compulsive Symptoms and Duration of Illness

OBJECTIVE

Whereas the evidence in adolescents is inconsistent, anorexia nervosa (AN) in adults is characterized by weak cognitive flexibility. This study investigates cognitive flexibility in adolescents with AN and its potential associations with symptoms of depression, obsessive compulsive disorder (OCD), and duration of illness.

METHODS

69 patients and 63 age-matched healthy controls (HC) from 9 till 19 years of age were assessed using the Trail-Making Test (TMT) and self-report questionnaires.

RESULTS

In hierarchical regression analyses, set-shifting ability did not differ between AN and HC, whereas AN patients reported significantly higher rates of depression symptoms and OCD symptoms. Age significantly predicted set-shifting in the total sample. Only among AN patients aged 14 years and older did set-shifting decline with increasing age.

DISCUSSION

The presence of AN with depression or OCD symptoms or the duration of illness do not influence cognitive flexibility in children and adolescents. Early interventions may be helpful to prevent a decline in cognitive flexibility in adolescent AN with increasing age.

Cognitive performance in children with acute early-onset anorexia nervosa

When anorexia nervosa (AN) occurs in children below the age of 14 years, it is referred to as early-onset AN (EO-AN). Over the last years, there has been an increased focus on the role of cognitive functioning in the development and maintenance of AN. Adults with AN show inefficiencies in cognitive functions such as flexibility and central coherence. Systematic neuropsychological examinations of patients with EO-AN are missing. Thirty children with EO-AN and 30 adolescents with AN, as well as 60 healthy controls (HC) underwent an extensive neuropsychological examination. ANOVAs with post hoc tests and explorative regression analyses were conducted. Patients with EO-AN (mean age = 2.17 ± 1.57 years) showed no significant differences in flexibility, inhibition, planning, central coherence, visuospatial short- and long-term memory or recognition in comparison to HC (mean age = 11.62 ± 1.29 years). Performance of adolescents with AN (mean age = 15.93 ± 0.70 years) was not significantly different compared to HC (mean age = 16.20 ± 1.26 years). Explorative regression analyses revealed a significant interaction of age and group for flexibility (adjusted R ²  = 0.30, F = 17.85, p = 0.013, η _p²  = 0.32). Contrary to expectations, the current study could not confirm the presence of inefficient cognitive processing in children with EO-AN compared to HC. Nonetheless, the expected age-related improvement of flexibility might be disrupted in children and adolescents with AN. Longitudinal neuropsychological examinations are necessary to provide more information about the role of cognitive functioning in the development and maintenance of AN.

Memory impairment is associated with the loss of regular oestrous cycle and plasma oestradiol levels in an activity-based anorexia animal model

OBJECTIVES

Patients with anorexia nervosa (AN) suffer from neuropsychological deficits including memory impairments. Memory partially depends on 17β-oestradiol (E2), which is reduced in patients with AN. We assessed whether memory functions correlate with E2 plasma levels in the activity-based anorexia (ABA) rat model.

METHODS

Nine 4-week-old female Wistar rats were sacrificed directly after weight loss of 20-25% (acute starvation), whereas 17 animals had additional 2-week weight-holding (chronic starvation). E2 serum levels and novel object recognition tasks were tested before and after starvation and compared with 21 normally fed controls.

RESULTS

Starvation disrupted menstrual cycle and impaired memory function, which became statistically significant in the chronic state (oestrous cycle (P < 0.001), E2 levels (P = 0.011) and object recognition memory (P = 0.042) compared to controls). E2 reduction also correlated with the loss of memory in the chronic condition (r = 0.633, P = 0.020).

CONCLUSIONS

Our results demonstrate that starvation reduces the E2 levels which are associated with memory deficits in ABA rats. These effects might explain reduced memory capacity in patients with AN as a consequence of E2 deficiency and the potentially limited effectiveness of psychotherapeutic interventions in the starved state. Future studies should examine whether E2 substitution could prevent cognitive deficits and aid in earlier readiness for therapy.

Are Weight Status and Cognition Associated? An Examination of Cognitive Development in Children and Adolescents with Anorexia Nervosa 1 Year after First Hospitalisation

Objective

The aim of this study was to characterise the association between the cognitive profile and weight restoration in children and adolescents with anorexia nervosa.

Methods

The study was a longitudinal, matched case–control, multicentre study. An assessment of cognitive functions was conducted by using the Wechsler Intelligence Scale for Children–III/the Wechsler Adult Intelligence Scale–III, the Test of Memory and Learning–second edition, Trail Making Tests A and B, the Rey–Osterrieth Complex Figure Test and the Cambridge Neuropsychological Test Automated Battery.

Results

One hundred twenty individuals, 60 patients with anorexia nervosa with mean age of 14.65 (SD 1.820) years and 60 healthy controls with mean age of 14.76 (SD 1.704) years, participated. No association was found between weight recovery and cognitive functions. However, a significant increase in motor speed was found in Trail Making Test A (p = 0.004), Reaction Time (RTI) five‐choice movement time (p = 0.002) and RTI simple movement time (p = 0.011), resulting in a normalisation corresponding to that found in healthy controls. Furthermore, a significantly lower score in the perceptual organization index (p = 0.029) was found at follow‐up.

Conclusions

Weight recovery appears not to be associated with cognition. Copyright © 2016 The Authors European Eating Disorders Review published by Eating Disorders Association and John Wiley & Sons Ltd

Planning Abilities in Patients with Anorexia Nervosa Compared with Healthy Controls

OBJECTIVE

Altered cognitive functioning could have an important role in the development and maintenance of Anorexia Nervosa (AN). The majority of previous research has focused on flexibility and global-detail processing. The aim of this study was to explore planning abilities in women with AN.

METHOD

Women with AN (n = 32) were compared to healthy controls (n = 42) using two different types of neuropsychological tasks for the assessment of planning abilities: Tower of London (ToL), a classic measure of planning abilities, and Zoo Map test, a more ecologically valid planning measure. Measures of AN psychopathology, anxiety, depression, and obsessive compulsivity were also collected.

RESULTS

The AN group did not differ from controls in the ToL (all p-values p > .05), although they performed significantly worse than controls in the main score of the Zoo Map (p = .02). A worse performance in the Zoo Map test More was associated with more eating disorders (rho = -.44, p = .018) and depressive (rho = -.42, p = .026) symptoms in the AN group.

CONCLUSIONS

Our study suggests the presence of subtle planning difficulties in women with AN which might be better detected using tasks with increased ecological validity.

Implicit sequence learning in juvenile anorexia nervosa: neural mechanisms and the impact of starvation

BACKGROUND

Previous studies have reported that cognitive deficits occur in patients with anorexia nervosa (AN) and that these deficits may represent a predisposition towards developing AN or perpetuate the disorder. Specifically, dysfunctional implicit learning may contribute to the development of highly resistant dieting behaviours that are fundamental to the persistence of the disorder. Thus, the aims of this study were (a) to investigate implicit sequence learning in adolescent patients with AN before and after weight recovery and (b) to elucidate the associated neural mechanisms in acute AN relative to healthy controls.

METHODS

In a behavioural study, implicit sequence learning was assessed using a serial reaction time task in 27 adolescents with AN before (T1) and after weight recovery (T2) compared with age-matched healthy controls (HC) who were assessed at similar time intervals. The neural correlates of implicit sequence learning were subsequently investigated in 19 AN patients shortly after they were admitted to the hospital and 20 HC using functional magnetic resonance imaging (fMRI).

RESULTS

At T1, AN patients showed reduced sequence learning compared with HC. However, no behavioural differences between HC and AN patients were found at T2. At the neural level, acute AN patients showed reduced thalamic activation during sequence learning compared with HC subjects.

CONCLUSIONS

Our data suggest that the impaired implicit learning observed in adolescent AN patients before weight gain is a state-related dysfunction that normalises with weight gain. Thus, implicit learning deficits do not appear to represent a predisposition towards developing AN; rather, these deficits should be considered when planning psychotherapeutic interventions for acute AN. Reduced thalamic activation during the acute stage of AN may indicate a starvation-induced dysfunction of the neural circuitry that is involved in behavioural flexibility.

Impaired executive functioning influences verbal memory in anorexia nervosa

BACKGROUND

How executive functioning affects delayed verbal recall in AN has never been tested. We investigated the influence of speed of information processing (SIP) and inhibition on delayed verbal recall in females with AN.

METHODS

Measures of SIP and inhibition from 35 females with AN were analyzed using hierarchical multiple regression after controlling for age, depressive symptomatology and body mass index. Each predictor was evaluated using structure coefficients, common variance and dominance weights.

RESULTS

The combination of measures of SIP and inhibition accounted for almost 80% of the variance on the delayed recall of the story recall task. When the rest of the variables were partialled out, SIP and inhibition accounted for more than 50% of the variance.

CONCLUSIONS

As it occurs with visuospatial abilities in AN, basic cognitive abilities such as speed of information processing and cognitive inhibition may affect other cognitive functions such as delayed verbal memory regardless of immediate recall. These findings may help interpret performance on cognitive tests in future research.

Morphological Changes in the Brain of Acutely Ill and Weight-Recovered Patients with Anorexia Nervosa

Objective: Acute anorexia nervosa (AN) leads to reduced gray (GM) and white matter (WM) volume in the brain, which however improves again upon restoration of weight. Yet little is known about the extent and clinical correlates of these brain changes, nor do we know much about the time-course and completeness of their recovery. Methods: We conducted a meta-analysis and a qualitative review of all magnetic resonance imaging studies involving volume analyses of the brain in both acute and recovered AN. Results: We identified structural neuroimaging studies with a total of 214 acute AN patients and 177 weight-recovered AN patients. In acute AN, GM was reduced by 5.6% and WM by 3.8% compared to healthy controls (HC). Short-term weight recovery 2–5 months after admission resulted in restitution of about half of the GM aberrations and almost full WM recovery. After 2–8 years of remission GM and WM were nearly normalized, and differences to HC (GM: –1.0%, WM: –0.7%) were no longer significant, although small residual changes could not be ruled out. In the qualitative review some studies found GM volume loss to be associated with cognitive deficits and clinical prognosis. Conclusions: GM and WM were strongly reduced in acute AN. The completeness of brain volume rehabilitation remained equivocal.

Adolescent Anorexia Nervosa: cognitive performance after weight recovery

OBJECTIVE

Although there is no definitive consensus on the impairment of neuropsychological functions, most studies of adults with Anorexia Nervosa (AN) find impaired functioning in cognitive domains such as visual-spatial abilities. The objective of this study is to assess the cognitive functions in adolescents with AN before and after weight recovery and to explore the relationship between cognitive performance and menstruation.

METHODS

Twenty-five female adolescents with AN were assessed by a neuropsychological battery while underweight and then following six months of treatment and weight recovery. Twenty-six healthy female subjects of a similar age were also evaluated at both time points.

RESULTS

Underweight patients with AN showed worse cognitive performance than control subjects in immediate recall, organization and time taken to copy the Rey's Complex Figure Test (RCFT). After weight recovery, AN patients presented significant improvements in all tests, and differences between patients and controls disappeared. Patients with AN and persistence of amenorrhea at follow-up (n=8) performed worse on Block Design, delayed recall of Visual Reproduction and Stroop Test than patients with resumed menstruation (n=14) and the control group, though the two AN groups were similar in body mass index, age and psychopathological scale scores.

CONCLUSION

Weight recovery improves cognitive functioning in adolescents with AN. The normalization of neuropsychological performance is better in patients who have recovered at least one menstrual cycle. The normalization of hormonal function seems to be essential for the normalization of cognitive performance, even in adolescents with a very short recovery time.

Primary amenorrhea in anorexia nervosa: impact on characteristic masculine and feminine traits

Animal studies indicate that gonadal hormones at puberty have an effect on the development of masculine and feminine traits. However, it is unknown whether similar processes occur in humans. We examined whether women with anorexia nervosa (AN), who often experience primary amenorrhea, exhibit attenuated feminization in their psychological characteristics in adulthood due to the decrease/absence of gonadal hormones at puberty. Women with AN were compared on a number of psychological characteristics using general linear models on the basis of the presence/absence of primary amenorrhea. Although women with primary amenorrhea exhibited lower anxiety scores than those without primary amenorrhea, in general, results did not provide evidence of attenuated feminization in women with AN with primary amenorrhea. Future research should utilize novel techniques and direct hormone measurement to explore the effects of pubertal gonadal hormones on masculine and feminine traits.

The relationship between anorexia nervosa and body dysmorphic disorder

Anorexia nervosa (AN) and body dysmorphic disorder (BDD) are severe body image disorders that highly impair individuals in their daily functioning. They are discrete but overlapping nosological entities. In this review, we examine similarities between AN and BDD with regard to clinical, personality and demographic aspects, such as comorbidity, phenomenology, and treatment outcome. The review suggests that the two disorders are highly comorbid, and show similar ages of onset, illness trajectories, and comparable clinical and personality characteristics. However, important differences emerge in their responsiveness to psychosocial and psychopharmacological treatment, which are discussed. Clinical implications of these findings are summarized and directions for future research are delineated, with a focus on how current treatment components from each disorder may inform new interventions for both disorders.

Ghrelin: central and peripheral implications in anorexia nervosa

Increasing clinical and therapeutic interest in the neurobiology of eating disorders reflects their dramatic impact on health. Chronic food restriction resulting in severe weight loss is a major symptom described in restrictive anorexia nervosa (AN) patients, and they also suffer from metabolic disturbances, infertility, osteopenia, and osteoporosis. Restrictive AN, mostly observed in young women, is the third largest cause of chronic illness in teenagers of industrialized countries. From a neurobiological perspective, AN-linked behaviors can be considered an adaptation that permits the endurance of reduced energy supply, involving central and/or peripheral reprograming. The severe weight loss observed in AN patients is accompanied by significant changes in hormones involved in energy balance, feeding behavior, and bone formation, all of which can be replicated in animals models. Increasing evidence suggests that AN could be an addictive behavior disorder, potentially linking defects in the reward mechanism with suppressed food intake, heightened physical activity, and mood disorder. Surprisingly, the plasma levels of ghrelin, an orexigenic hormone that drives food-motivated behavior, are increased. This increase in plasma ghrelin levels seems paradoxical in light of the restrained eating adopted by AN patients, and may rather result from an adaptation to the disease. The aim of this review is to describe the role played by ghrelin in AN focusing on its central vs. peripheral actions. In AN patients and in rodent AN models, chronic food restriction induces profound alterations in the « ghrelin » signaling that leads to the development of inappropriate behaviors like hyperactivity or addiction to food starvation and therefore a greater depletion in energy reserves. The question of a transient insensitivity to ghrelin and/or a potential metabolic reprograming is discussed in regard of new clinical treatments currently investigated.

Event-related potentials during recognition of semantic and pictorial food stimuli in patients with anorexia nervosa and healthy controls with varying internal states of hunger

OBJECTIVE

To elucidate maladaptive central processing of food cues during recognition tasks in anorexia nervosa (AN), while considering influences of nutritional preload and presentation modality (word versus picture).

METHODS

Event-related potentials to food-related word and pictorial stimuli were assessed during recognition tasks in 16 patients with AN, 16 control participants with food intake before the study, and 16 control participants with a fasting period before the study.

RESULTS

Patients with AN showed a P3b amplitude reduction especially at the midline parietal site compared with satiated controls (5.7 [standard deviation = 3.3] versus 8.7 [3.1] μV, p < .03). Subtle recognition deficits in patients with AN were indicated by smaller "old/new" effects compared with satiated (p = .049) and fasting controls (p < .003) for pictorial stimuli. Hunger-modulated enhanced old/new effects for food pictures compared with neutral pictorial stimuli could be observed in fasting controls only (2.7 [2.6] versus 0.8 [2.2] μV, p < .01).

CONCLUSIONS

The presented data provide evidence for a midline parietal P3b amplitude reduction in patients with AN, which might point to reduced network activation in AN even during satiety. Observed subtle recognition deficits either represent a stable trait characteristic or a "scar" effect of chronic starvation that may play a role in the development and/or persistence of the disorder.

Aetiology of anorexia nervosa: from a "psychosomatic family model" to a neuropsychiatric disorder?

Eating disorders and, in particular, anorexia nervosa (AN) have morbidity and mortality rates that are among the highest of any mental disorders and are associated with significant functional impairment. More than 25 years ago, several researchers hypothesised that the prerequisite for the development of AN was a family process characterised by an overprotective and conflict-avoiding parent-child interaction. Family studies, however, suggest that AN is a complex genetic disorder that is likely expressed primarily by temperament and specific traits during childhood, including inhibition, perfectionism and harm avoidance. Recent studies have described an impaired flexibility and deficits in social cognition that are independent of body weight and the current state of the eating disorder, providing further evidence for a genetic component of AN. The physiological and psychological alterations and the increasing societal demands that occur during puberty may trigger onset. The starvation process itself is associated with severe alterations of central and peripheral metabolism, especially neuroendocrine and neurotransmitter changes, which are thought to affect the adolescent brain during the vulnerable period of neural restructuring. Long-standing malnutrition during adolescence and young adulthood associated with hormonal and neuropeptide dysfunctions may produce "biological scars" that maintain and accelerate the disorder and likely result in chronic mental disorders in adulthood as well as poor social functioning.