A proof-of-concept study applying machine learning methods to putative risk factors for eating disorders: results from the multi-centre European project on healthy eating.

BACKGROUND: Despite a wide range of proposed risk factors and theoretical models, prediction of eating disorder (ED) onset remains poor. This study undertook the first comparison of two machine learning (ML) approaches [penalised logistic regression (LASSO), and prediction rule ensembles (PREs)] to conventional logistic regression (LR) models to enhance prediction of ED onset and differential ED diagnoses from a range of putative risk factors. METHOD: Data were part of a European Project and comprised 1402 participants, 642 ED patients [52% with anorexia nervosa (AN) and 40% with bulimia nervosa (BN)] and 760 controls. The Cross-Cultural Risk Factor Questionnaire, which assesses retrospectively a range of sociocultural and psychological ED risk factors occurring before the age of 12 years (46 predictors in total), was used. RESULTS: All three statistical approaches had satisfactory model accuracy, with an average area under the curve (AUC) of 86% for predicting ED onset and 70% for predicting AN v. BN. Predictive performance was greatest for the two regression methods (LR and LASSO), although the PRE technique relied on fewer predictors with comparable accuracy. The individual risk factors differed depending on the outcome classification (EDs v. non-EDs and AN v. BN). CONCLUSIONS: Even though the conventional LR performed comparably to the ML approaches in terms of predictive accuracy, the ML methods produced more parsimonious predictive models. ML approaches offer a viable way to modify screening practices for ED risk that balance accuracy against participant burden.

Functional electronic inversion layers at ferroelectric domain walls.

Ferroelectric domain walls hold great promise as functional two-dimensional materials because of their unusual electronic properties. Particularly intriguing are the so-called charged walls where a polarity mismatch causes local, diverging electrostatic potentials requiring charge compensation and hence a change in the electronic structure. These walls can exhibit significantly enhanced conductivity and serve as a circuit path. The development of all-domain-wall devices, however, also requires walls with controllable output to emulate electronic nano-components such as diodes and transistors. Here we demonstrate electric-field control of the electronic transport at ferroelectric domain walls. We reversibly switch from resistive to conductive behaviour at charged walls in semiconducting ErMnO3. We relate the transition to the formation-and eventual activation-of an inversion layer that acts as the channel for the charge transport. The findings provide new insight into the domain-wall physics in ferroelectrics and foreshadow the possibility to design elementary digital devices for all-domain-wall circuitry.

Late onset eating disorders in Spain: clinical characteristics and therapeutic implications.

OBJECTIVE: The literature on later age of onset (LAO) in women with eating disorders is scarce. We compared the severity of eating disorders, eating disorder subtype, and personality profiles in a clinical sample of consecutively assessed women with eating disorders with later age of onset (LAO, > = 25 years) to women with typical age of onset (TAO, <25 years). METHOD: All eating disorder patients met the Diagnostic and Statistical Manual of Mental Disorders Fourth Edition (DSM-IV) criteria and were admitted to the Eating Disorder Unit of the University Hospital of Bellvitge in Barcelona, Spain. Ninety-six patients were classified as LAO and 759 as TAO. ASSESSMENT: Measures included the Eating Attitude Test-40 (EAT-40), Eating Disorders Inventory-2 (EDI-2), Bulimic Investigatory Test Edinburgh (BITE), Symptom Checklist Revised (SCL-90-R), and the Temperament and Character Inventory-Revised (TCI-R), as well as other clinical and psychopathological indices. RESULTS: LAO individuals reported significantly fewer weekly vomiting episodes, fewer self-harming behaviours, less drug abuse, and lower scores on the BITE symptoms, the EDI-2 drive for thinness, and the TCI-R harm avoidance scales than TAO individuals. Conversely, the LAO group reported more current and premorbid obesity than the TAO group. CONCLUSION: LAO eating disorder patients in this sample presented with milder symptomatology and less extreme personality traits. Premorbid obesity may be more relevant to LAO than TAO eating disorders and should be routinely assessed and considered when planning treatment.

Eating-related environmental factors in underweight eating disorders and obesity: are there common vulnerabilities during childhood and early adolescence?

OBJECTIVE: This study aimed to examine whether there is an association between individual, social and family influences and dysfunctional eating patterns early in life and the likelihood of developing a subsequent underweight eating disorder (ED) or obesity. METHOD: The total sample comprised 152 individuals (underweight ED, n = 45; obese patients, n = 65; healthy controls; n = 42) from Barcelona, Spain. The Cross-Cultural Questionnaire (CCQ) was used to assess early eating influences as well as individual and family eating patterns and attitudes towards food. RESULTS: Even though a few shared eating influences emerged for both groups, unique factors were also observed. Whereas relationship with friends, teasing about eating habits by family members and the mass media were of specific relevance to the underweight ED group, the patient's own physical appearance, body dissatisfaction, teasing about eating habits by friends, teasing about body shape by family members and dysfunctional eating patterns were unique to obesity. CONCLUSIONS: Overlapping environmental risk factors provide evidence for integral prevention and intervention approaches that simultaneously tackle a range of weight-related problems. The unique factors might be important for targeting high-risk individuals.

Dating app usage and motivations for dating app usage are associated with increased disordered eating.

The centrality of physical appearance in dating app environments may constitute an appearance-related pressure that increases the likelihood of body dissatisfaction (BD) and disordered eating (DE), thus exacerbating the relationship between DE-predictive traits and DE itself. Although dating app use has been linked to BD and DE, prior research has also neglected the role of individuals' dating app use motivations and relevant traits in eating pathology. To address these gaps, the current study investigated whether dating app usage moderated the effects of appearance-based rejection sensitivity, fear of negative evaluation, emotion dysregulation, and perceived social rank on DE. We also examined the unique effects of individuals' dating app use motivations on DE. Participants (N = 690) completed baseline measures of demographic and trait variables including dating app usage. DE was positively associated with female gender, higher body mass index, a history of eating disorder (ED) diagnosis, appearance-based rejection sensitivity, and emotion dysregulation. There was a small, positive association between dating app usage and DE, indicating that dating app users were more likely to report DE symptoms, appearance-based rejection sensitivity, and emotion dysregulation. No investigated predictor was moderated by dating app usage, but four of the six measured motivations for using dating apps (love, self-worth, ease of communication, and thrill of excitement motivations) were associated with DE among the dating app user sample (casual sex and trendiness motivations were not). Given that DE behaviours can lead to EDs, the present findings suggest that lifetime dating app usage may increase socio-cultural appearance pressures that confer risk for DE.

Existing research evidence, although scant, has linked dating app use to body dissatisfaction (BD) and disordered eating (DE). Yet, little is known about the relationship between individuals' dating app use motivations and relevant traits in eating pathology. To address these gaps, the current study investigated whether dating app usage moderated the effects of appearance-based rejection sensitivity (appearance-RS), fear of negative evaluation (FNE), emotion dysregulation, and perceived social rank on DE, and the unique association between individuals' dating app use motivations and DE. Participants (N = 690) completed baseline measures of demographic and trait variables including dating app usage. We found that dating app users were more likely to engage in DE behaviours, appearance-RS, and emotion dysregulation than non-users. Furthermore, four of the six measured motivations for using dating apps were associated with DE among the dating app user sample. We conclude that lifetime dating app usage may constitute a socio-cultural appearance pressure which confers DE risk. Our results showed also novel insights into the varied motivations for dating app use and their impacts on DE. As dating app use continues to proliferate, enhancing our understanding of how, why and for whom it may be harmful remains a salient area of research.

Is season of birth related to disordered eating and personality in women with eating disorders?

We assessed the relation between season of birth and eating disorder symptoms and personality characteristics in a sample of 880 women with eating disorders and 580 controls from two Price Foundation Studies. Eating disorder symptoms were assessed using the Structured Interview of Anorexic and Bulimic Disorders and the Structured Clinical Interview for DSM-IV. Personality traits were assessed using the Temperament and Character Inventory and the Frost Multidimensional Perfectionism Scale. Date of birth was obtained from a sociodemographic questionnaire. No significant differences were observed 1) in season of birth across eating disorder subtypes and controls; nor 2) for any clinical or personality variables and season of birth. We found no evidence of season of birth variation in eating disorders symptoms or personality traits. Contributing to previous conflicting findings, the present results do not support a season of birth hypothesis for eating disorders.

Motivation to change in eating disorders: clinical and therapeutic implications.

OBJECTIVES: The aim of this study was to understand the clinical impact of the motivational stage of change on the psychopathology and symptomatology of anorexia nervosa (AN), bulimia nervosa (BN) and eating disorders not otherwise specified (EDNOS). METHOD: The participants were 218 eating disorder (ED) patients (58 AN, 95 BN and 65 EDNOS), consecutively admitted to our hospital. All patients fulfilled DSM-IV criteria for these disorders. ASSESSMENT: Assessment measures included the Eating Disorders Inventory (EDI), Bulimic Investigation Test Edinburgh (BITE), Beck Depression Inventory (BDI), four analogue scales of motivational stage, as well as a number of other clinical and psychopathological indices. RESULTS: Our results indicated higher motivation for change in BN than in AN and EDNOS patients (p < 0.05). For all groups, motivation to change was predicted by chronological age (p < 0.05). However, a longer duration of illness was only predictive of the motivational levels in EDNOS (p < 0.05) patients. CONCLUSIONS: Compared to BN, AN and EDNOS patients are most resistant to change and the younger these patients are, the less likely they are to be motivated to change their disturbed eating behaviour.

Cognitive effects of dopaminergic and glutamatergic blockade in nucleus accumbens in pigeons.

In earlier studies it was found that glutamatergic transmission within the nucleus accumbens septi is involved in the performance of a learned visual shape discrimination in pigeons. This study examines what effects several kinds of glutamate and dopamine antagonists have on the same task. Pigeons were trained with the relevant discrimination, bilaterally implanted with cannulas into the nucleus accumbens and tested after various transmission blockers had been administered intracerebrally. SCH-23390, a D1 dopamine antagonist, at the dose used, had no effect, and Spiperone, a D2-dopamine and 5HT2a-serotonine antagonist, significantly decreased the error repeat trials. CNQX, a non-NMDA glutamate receptor antagonist, and Cycloleucine, an antagonist of the glycine allosteric site of NMDA receptors, had no effect. CGS-19755, a selective competitive NMDA antagonist, significantly impaired performance by significantly decreasing the percent correct trials and increasing the error repeat trials. CPPG, a II/III metabotropic glutamate antagonist, remarkably improved performance. MMPG, a III/II metabotropic glutamate antagonist, at the dose used, did not have any significant effect. The preparation employed may be a useful animal model of perceptual disturbances in schizophrenia.

Time-resolved magnetic imaging in an aberration-corrected, energy-filtered photoemission electron microscope.

We report on the implementation and usage of a synchrotron-based time-resolving operation mode in an aberration-corrected, energy-filtered photoemission electron microscope. The setup consists of a new type of sample holder, which enables fast magnetization reversal of the sample by sub-ns pulses of up to 10 mT. Within the sample holder current pulses are generated by a fast avalanche photo diode and transformed into magnetic fields by means of a microstrip line. For more efficient use of the synchrotron time structure, we developed an electrostatic deflection gating mechanism capable of beam blanking within a few nanoseconds. This allows us to operate the setup in the hybrid bunch mode of the storage ring facility, selecting one or several bright singular light pulses which are temporally well-separated from the normal high-intensity multibunch pulse pattern.