Efficacy and cost-effectiveness of Internet-based selective eating disorder prevention: study protocol for a randomized controlled trial within the ProHEAD Consortium.

BACKGROUND: The development of efficacious, cost-effective, and widely accessible programs for the prevention of eating disorders (EDs) is crucial in order to reduce the ED-related burden of illness. Programs using dissonance-based and cognitive behavioral approaches are most effective for the selective prevention of ED. Internet-based delivery is assumed to maximize the reach and impact of preventive efforts. However, the current evidence for Internet-based ED prevention is limited. The present trial evaluates the efficacy and cost-effectiveness of two new interventions (based on dissonance theory and principles of cognitive behavioral therapy (CBT)) that are implemented as add-ons to the existing Internet-based ED prevention program ProYouth. METHODS: The trial is one of five sub-projects of the German multicenter consortium ProHEAD. It is a three-arm, parallel, randomized controlled superiority trial. Participants will be randomized to (1) the online program ProYouth (active control condition) or (2) ProYouth plus a structured dissonance-based module or (3) ProYouth plus a CBT-based chat group intervention. As part of ProHEAD, a representative school-based sample of N = 15,000 students (≥ 12 years) will be screened for mental health problems. N = 309 participants at risk for ED (assessed with the Weight Concerns Scale (WCS) and the Short Evaluation of Eating Disorders (SEED)) will be included in the present trial. Online assessments will be conducted at baseline, at end of intervention (6 weeks), at 6 months follow-up, and - as part of ProHEAD - at 12 and 24 months follow-up. The primary outcome is ED-related impairment (assessed with the Child version of the Eating Disorder Examination-Questionnaire (ChEDE-Q)) at the end of the intervention. Secondary outcomes include ED-related symptomatology at follow-up, ED-related stigma, ED-related help-seeking, and acceptance of and compliance with the interventions. For the health economic evaluation data on costs of the interventions, healthcare utilization and health-related quality of life will be assessed. DISCUSSION: This is the first study augmenting a flexible prevention approach such as ProYouth with structured evidence-based modules in order to overcome some of the key limitations in the current practice of ED prevention. TRIAL REGISTRATION: German Clinical Trials Register (DRKS), DRKS00014679 . Registered on 25 April 2018.

Approach bias and cue reactivity towards food in people with high versus low levels of food craving.

OBJECTIVE: Even though people suffering from high levels of food craving are aware of the negative consequences of binge eating, they cannot resist. Automatic action tendencies (i.e. approach bias) towards food cues that operate outside conscious control may contribute to this dysfunctional behavior. The present study aimed to examine whether people with high levels of food craving show a stronger approach bias for food than those with low levels of food craving and whether this bias is associated with cue-elicited food craving. METHOD: Forty-one individuals reporting either extremely high or extremely low levels of trait food craving were recruited via an online screening and compared regarding approach bias towards visual food cues by means of an implicit stimulus-response paradigm (i.e. the Food Approach-Avoidance Task). State levels of food craving were assessed before and after cue exposure to indicate food cue reactivity. RESULTS: As expected, high food cravers showed stronger automatic approach tendencies towards food than low food cravers. Also in line with the hypotheses, approach bias for food was positively correlated with the magnitude of change in state levels of food craving from pre-to post-cue exposure in the total sample. DISCUSSION: The findings suggest that an approach bias in early stages of information processing contributes to the inability to resist food intake and may be of relevance for understanding and treating dysfunctional eating behavior.

Approach Bias Modification in Food Craving-A Proof-of-Concept Study.

The aim of the present proof-of-concept study was to test a novel cognitive bias modification (CBM) programme in an analogue sample of people with subclinical bulimic eating disorder (ED) psychopathology. Thirty participants with high levels of trait food craving were trained to make avoidance movements in response to visual food stimuli in an implicit learning paradigm. The intervention comprised ten 15-minute sessions over a 5-week course. At baseline, participants showed approach and attentional biases towards high-caloric palatable food that were both significantly reduced and turned into avoidance biases after the training. Participants also reported pronounced reductions in both trait and cue-elicited food craving and in ED symptoms as well. The overall evaluation of the training by the participants was positive. The specific CBM programme tested in this pilot trial promises to be an effective and feasible way to alter automatic action tendencies towards food in people suffering from bulimic ED psychopathology.

A size barrier limits protein diffusion at the cell surface to generate lipid-rich myelin-membrane sheets.

The insulating layers of myelin membrane wrapped around axons by oligodendrocytes are essential for the rapid conduction of nerve impulses in the central nervous system. To fulfill this function as an electrical insulator, myelin requires a unique lipid and protein composition. Here we show that oligodendrocytes employ a barrier that functions as a physical filter to generate the lipid-rich myelin-membrane sheets. Myelin basic protein (MBP) forms this molecular sieve and restricts the diffusion of proteins with large cytoplasmic domains into myelin. The barrier is generated from MBP molecules that line the entire sheet and is, thus, intimately intertwined with the biogenesis of the polarized cell surface. This system might have evolved in oligodendrocytes in order to generate an anisotropic membrane organization that facilitates the assembly of highly insulating lipid-rich membranes.