Prefrontal Responses during Proactive and Reactive Inhibition Are Differentially Impacted by Stress in Anorexia and Bulimia Nervosa.

Binge eating is a distressing, transdiagnostic eating disorder symptom associated with impulsivity, particularly in negative mood states. Neuroimaging studies of bulimia nervosa (BN) report reduced activity in frontostriatal regions implicated in self-regulatory control, and an influential theory posits that binge eating results from self-regulation failures under stress. However, there is no direct evidence that psychological stress impairs self-regulation in binge-eating disorders, or that any such self-regulatory deficits generalize to binge eating in underweight individuals (i.e., anorexia nervosa bingeing/purging subtype; AN-BP). We therefore determined the effect of acute stress on inhibitory control in 85 women (BN, 33 women; AN-BP, 22 women; 30 control participants). Participants underwent repeated functional MRI scanning during performance of the Stop-signal anticipation task, a validated measure of proactive (i.e., anticipation of stopping) and reactive (outright stopping) inhibition. Neural and behavioral responses to induced stress and a control task were evaluated on 2 consecutive days. Women with BN had reduced proactive inhibition, while prefrontal responses were increased in both AN-BP and BN. Reactive inhibition was neurally and behaviorally intact in both diagnostic groups. Both AN-BP and BN groups showed distinct stress-induced changes in inferior and superior frontal activity during both proactive and reactive inhibition. However, task performance was unaffected by stress. These results offer novel evidence of reduced proactive inhibition in BN, yet inhibitory control deficits did not generalize to AN-BP. Our findings identify intriguing alterations of stress responses and inhibitory function associated with binge eating, but they counsel against stress-induced failures of inhibitory control as a comprehensive explanation for loss-of-control eating.SIGNIFICANCE STATEMENT Binge eating is a common psychiatric syndrome that feels uncontrollable to the sufferer. Theoretically, it has been related to reduced self-regulation under stress, but there remains no direct evidence for this link in binge-eating disorders. Here, we examined how experimentally induced stress affected response inhibition in control participants and women with anorexia nervosa and bulimia nervosa. Participants underwent repeated brain scanning under stressful and neutral conditions. Although patient groups had intact action cancellation, the slowing of motor responses was impaired in bulimia nervosa, even when the likelihood of having to stop increased. Stress altered brain responses for both forms of inhibition in both groups, yet performance remained unimpaired. These findings counsel against a simple model of stress-induced disinhibition as an adequate explanation for binge eating.

Dissociable hormonal profiles for psychopathology and stress in anorexia and bulimia nervosa.

BACKGROUND: Anorexia nervosa (AN) and bulimia nervosa (BN) are complex psychiatric conditions, in which both psychological and metabolic factors have been implicated. Critically, the experience of stress can precipitate loss-of-control eating in both conditions, suggesting an interplay between mental state and metabolic signaling. However, associations between psychological states, symptoms and metabolic processes in AN and BN have not been examined. METHODS: Eighty-five women (n = 22 AN binge/purge subtype, n = 33 BN, n = 30 controls) underwent remote salivary cortisol sampling and a 2-day, inpatient study session to examine the effect of stress on cortisol, gut hormones [acyl-ghrelin, peptide tyrosine tyrosine (PYY) and glucagon-like peptide-1] and food consumption. Participants were randomized to either an acute stress induction or control task on each day, and plasma hormones were serially measured before a naturalistic, ad libitum meal. RESULTS: Cortisol-awakening response was augmented in AN but not in BN relative to controls, with body mass index explaining the most variance in post-awakening cortisol (36%). Acute stress increased acyl-ghrelin and PYY in AN compared to controls; however, stress did not alter gut hormone profiles in BN. Instead, a group-by-stress interaction showed nominally reduced cortisol reactivity in BN, but not in AN, compared to controls. Ad libitum consumption was lower in both patient groups and unaffected by stress. CONCLUSIONS: Findings extend previous reports of metabolic dysfunction in binge-eating disorders, identifying unique associations across disorders and under stress. Moreover, we observed disrupted homeostatic signaling in AN following psychological stress, which may explain, in part, the maintenance of dysregulated eating in this serious illness.

Early warning systems in inpatient anorexia nervosa: A validation of the MARSIPAN-based modified early warning system.

OBJECTIVE: We aimed to evaluate the validity of a MARSIPAN-guidance-adapted Early Warning System (MARSI MEWS) and compare it to the National Early Warning Score (NEWS) and an adapted version of the Physical Risk in Eating Disorders Index (PREDIX), to ascertain whether current practice is comparable to best-practice standards. METHODS: We collated 3,937 observations from 36 inpatients from Addenbrookes Hospital over 2017-2018 and used three independent raters to create a "gold standard" of deteriorating cases. We ascertained performance metrics (Receiver Operating Characteristic Area Under the curve) for MARSI MEWS, NEWS and PREDIX; we also tested the proof of concept of a machine-learning-based early-warning-system (ML-EWS) using cross-validation and out-of-sample prediction of cases. RESULTS: The MARSI MEWS system showed higher ROC AUC (0.916) compared to NEWS (0.828) or PREDIX (0.865). ML-EWS (random forest) performed well at independent samples analysis (0.980) and multilevel analysis (0.922). CONCLUSION: MARSI MEWS seems most suitable for identifying critically deteriorating cases in anorexia nervosa inpatient population. We did not examine community practice in which the PREDIX arguably remains the best to ascertain deteriorating cases. Our results also provide a first proof of concept for the development of artificial-intelligence-based early warning systems in anorexia nervosa. Implications for inpatient clinical practice in eating disorders are discussed.

Bulimia nervosa patient diagnosed with previously unsuspected ADHD in adulthood: clinical case report, literature review, and diagnostic challenges.

There is increasing literature suggesting a link between attention-deficit hyperactivity disorder (ADHD) and eating disorders (EDs), especially bulimia nervosa. ADHD is under-diagnosed in girls and children of high intelligence are typically missed. We identified a case of a 23-year-old woman suffering from severe bulimia nervosa and previously unsuspected ADHD in adulthood; we diagnosed and treated her with extended-release methylphenidate. We performed a literature review on the ADHD and bulimia nervosa comorbidity. We discuss the reasons why her ADHD remained undiagnosed and the difficulties in diagnosing ADHD in patients with EDs. We suggest that identifying comorbid ADHD is crucial for these patients and argue for the use of a structured interview, collateral history and investigation of onset of symptoms to establish a diagnosis of ADHD in adults with bulimia nervosa. Comorbidities and overlap of symptomatology need to be taken into account.

Conservation of structural and functional elements of TSC1 and TSC2: a bioinformatic comparison across animal models.

The tuberous sclerosis complex 1/2-mammalian target of rapamycin (TSC1/2-mTOR) proteins act as integrators of a range of intracellular signalling pathways. Various genetic disorders associated with learning and behavioural deficits, including TSC, Fragile X, Neurofibromatosis Type 1, Noonan and Leopard syndromes, are associated with abnormalities in TSC-mTOR signalling. Based on the assumption that signalling proteins and their structural and functional components are widely conserved, a number of animal models are used to study aspects of the physical and behavioural phenotypes of these human disorders. Model organisms include rat (Rattus norvegicus), mouse (Mus musculus), zebrafish (Danio rerio), fruitfly (Drosophila melanogaster) and fission yeast (Schizosaccharomyces pombe). Here we used a bioinformatic approach to examine the presence of structural and functional elements of TSC1 and TSC2 across these organisms, together with Strongylocentrotus purpuratus and Dictyostelium discoideum. Results suggest that while Rattus norvegicus and Mus musculus TSC1 and TSC2 showed very high similarity to the human sequences, this was not the case for Danio rerio, Drosophila melanogaster, Strongylocentrotus purpuratus, Schizosaccharomyces pombe or Disctyostelium discoideum. Findings indicate that caution should be exercised in detailed interpretation of results from some model organisms.

Psychiatric discharge summaries: what do general practitioners want?

Aims As part of an initiative to improve and standardise our discharge summaries, we investigated the preferences of general practitioners (GPs) with regards to the information provided in summaries.Method Our study methods included sending a questionnaire to all GPs in our area gathering their views on what information to include in discharge summaries on first and on subsequent inpatient episodes.Results The response rate was 68%. Most GPs wanted a comprehensive first discharge summary, particularly stressing the importance of practical information. Subsequent discharge summaries could exclude case histories.Clinical implications Contrary to previous studies indicating a demand for brief reports, this survey indicates that the GPs surveyed value considerable detail in adult psychiatry discharge summaries. It is important to include these views in setting standards for the auditing process and before implementing changes.

Neuropsychological attention skills and related behaviours in adults with tuberous sclerosis complex.

Tuberous sclerosis complex (TSC) is a genetic disorder associated with mTOR over-activation and disruption of MAPK, PI3K and AMPK signalling. Children with TSC have significant deficits on neuropsychological attention tasks, particularly dual tasking. Here we investigated attentional skills and related behaviours in daily life in normally intelligent adults with TSC and matched controls using the Test of Everyday Attention for Children (TEA-Ch) and the Attention-Deficit Scales for Adults (ADSA). No group differences were demonstrated on selective or sustained attention tasks carried out alone. However, adults with TSC performed significantly worse when these tasks were combined in a cross-modal dual task condition. On the ADSA the TSC group had significantly worse scores on several subscales (attention/concentration, behaviour/disorganization, academic and emotional behaviours) compared to controls and these correlated with dual task performance, indicating a clear impact of dual task deficits on attention-related behaviours in daily life. The presence or absence of epilepsy did not influence dual task performance or attention-deficits in daily life. Taken together with similar findings in children, results suggest that dual task difficulties are a core feature of the neuropsychological phenotype of TSC.

Evolution of the TSC1/TSC2-TOR signaling pathway.

The TSC1/TSC2-TOR signaling pathway [the signaling pathway that includes the heterodimeric TSC1 (tuberous sclerosis 1 protein)-TSC2 (tuberous sclerosis 2 protein) complex and TOR (target of rapamycin)] regulates various cellular processes, including protein synthesis, in response to growth factors and nutrient availability. Homologs of some pathway components have been reported from animals, fungi, plants, and protozoa. These observations led to the perception that the whole pathway is evolutionarily conserved throughout eukaryotes. Using complete genome sequences, we show that, contrary to this view, the pathway was built up from a simpler one, present in the ancestral eukaryote, coupling cell growth to energy supplies. Additional elements, such as TSC1 and TSC2, were "bolted on" in particular eukaryotic lineages. Our results also suggest that unikonts [Opisthokonta (including animals and fungi) and Amoebozoa] form a monophyletic group with the Excavata and Chromalveolata. A previous proposal, that the root of the eukaryotic "tree of life" lies between the unikonts and other organisms, should therefore be reevaluated.