Lisdexamfetamine Dimesylate Effects on Binge Eating Behaviour and Obsessive-Compulsive and Impulsive Features in Adults with Binge Eating Disorder

Exploring bi-directional impacts of Lisdexamfetamine dimesylate on psychological comorbidities and quality of life in people with Binge Eating Disorder

BACKGROUND

Lisdexamfetamine dimesylate (LDX) has demonstrated safety and efficacy for treatment of Binge Eating Disorder (BED). However, to date, trials have not included participants with co-occurring psychiatric disorders. This study explores how LDX affects eating disorder psychopathology, symptoms of common psychiatric comorbidities of BED (ADHD, depression, anxiety), and psychological quality of life, in people with moderate to severe BED.

METHODS

These are secondary analyses of an open-label LDX trial conducted in 41 adults (18-40 years) over eight-weeks. Participants received LDX titrated to 50 or 70 mg. Clinical assessments and self-report questionnaires were conducted at baseline and 8-week follow-up.

RESULTS

Eating disorder psychopathology and psychological quality of life improved after 8-weeks of LDX. No significant group-level changes in depression, anxiety or ADHD severity scores were observed. However, the majority within the small subsets with elevated depression and ADHD symptoms experienced reduced depressive and inattentive symptom severity, respectively.

CONCLUSIONS

We provide proof-of-concept evidence that LDX may provide broader psychological benefits to individuals with BED, beyond reducing their BE frequency. Effects of LDX on anxiety should be monitored closely by clinicians. Early indications suggest that LDX may be effectively used in people with BED, with and without co-occurring psychiatric conditions, however tolerability may be lower in highly complex cases.

TRIAL REGISTRATION

Australian and New Zealand Clinical Trials Registry (anzctr.org.au) #ACTRN12618000623291.

GLP-1 receptor agonists: A novel pharmacotherapy for binge eating (Binge eating disorder and bulimia nervosa)? A systematic review

Objective

Systematically review evidence on using GLP-1RAs for reducing BEB in BED and BN.

Methods

Comprehensive literature search (PubMed and Google Scholar) conducted for studies evaluating GLP-1Ras for BEB. Extracted data on study characteristics, efficacy, and safety.

Results

Studies show that GLP-1RAs (liraglutide and dulaglutide) reduce BE frequency and comorbidities in addition to favorable psychiatric side effect profile compared to current options. However, large-scale, blinded placebo-controlled trials are lacking.

Conclusion

Early findings suggest promising effects of GLP-1RAs on BEB. However, rigorous clinical trials are needed to firmly establish efficacy, dosing, safety, and comparative effectiveness before considering GLP-1RAs a viable novel approach.

Functional Connectivity Mechanisms Underlying Symptom Reduction Following Lisdexamfetamine Treatment in Binge-Eating Disorder: A Clinical Trial

Background

Speculation exists as to whether lisdexamfetamine dimesylate (LDX) acts on the functional connectivity (FC) of brain networks that modulate appetite, reward, or inhibitory control in binge-eating disorder (BED). Better insights into its action may help guide the development of more targeted therapeutics and identify who will benefit most from this medication. Here, we use a comprehensive data-driven approach to investigate the brain FC changes that underlie the therapeutic action of LDX in patients with BED.

Methods

Forty-six participants with moderate to severe BED received LDX titrated to 50 or 70 mg for an 8-week period. Twenty age-matched healthy control participants were also recruited. Resting-state functional magnetic resonance imaging was used to probe changes in brain FC pre- and post treatment and correlated with change in clinical measures.

Results

Ninety-seven percent of trial completers (n = 31) experienced remission or a reduction to mild BED during the 8-week LDX trial. Widespread neural FC changes occurred, with changes in default mode to limbic, executive control to subcortical, and default mode to executive control networks associated with improvements in clinical outcomes. These connections were not distinct from control participants at pretreatment but were different from control participants following LDX treatment. Pretreatment connectivity did not predict treatment response.

Conclusions

FC between networks associated with self-referential processing, executive function, and reward seem to underlie the therapeutic effect of LDX in BED. This suggests that LDX activates change via multiple systems, with most changes in compensatory networks rather than in those characterizing the BED diagnosis.

Stimulant prodrugs: A pharmacological and clinical assessment of their role in treating ADHD and binge-eating disorder

In this review, we critically evaluate the contribution of prodrugs to treating two related psychiatric disorders, attention-deficit hyperactivity disorder (ADHD) and binge-eating disorder (BED). ADHD is characterized by inattentiveness, distractibility, impulsiveness, and hyperactivity. BED is also an impulse-control disorder which leads to frequent, compulsive episodes of excessive eating (binges). Lisdexamfetamine (LDX; prodrug of d-amphetamine) is approved to treat both ADHD and BED. Serdexmethylphenidate (SDX; prodrug of d-threo-methylphenidate) is not clinically approved as monotherapy but, in a fixed-dose combination with immediate release d-threo-methylphenidate (Azstarys™), SDX is approved for managing ADHD in children/adolescents. The pharmacological actions of a stimulant mediate both its efficacy and side-effects. Therefore, daily management of ADHD or BED to maintain optimum efficacy and tolerability places highly restrictive requirements on the pharmacokinetic/pharmacodynamic (PK/PD) characteristics of stimulant medications, especially prodrugs. Prodrugs must have good bioavailability and rapid metabolism to provide therapeutic efficacy soon after morning dosing combined with providing stimulant coverage throughout the day/evening. A wide selection of dosages and linear PK for the prodrug and its active metabolite are essential requirements for treatment of these conditions. The proposed neurobiological causes of ADHD and BED are described. The chemical, pharmacological and PK/PD properties responsible for the therapeutic actions of the prodrugs, LDX and SDX, are compared and contrasted. Finally, we critically assess their contribution as ADHD and BED medications, including advantages over their respective active metabolites, d-amphetamine and d-threo-methylphenidate, and also their potential for misuse and abuse.

Pharmacological strategies for appetite modulation in eating disorders: a narrative review

BACKGROUND

A substantial increase in the prevalence of eating disorders has been noticed over the past decades. Priority in the treatment of eating disorders is justifiably given to psychosocial interventions. However, it is also well known that centrally acting drugs can significantly affect appetite and food consumption.

AIM

To narratively review the available neurobiological data on the mechanisms of central regulation of eating behavior as a rationale to summarize pharmacological strategies for appetite modulation in eating disorders.

METHODS

The authors have carried out a narrative review of scientific papers published from January 2013 to March 2023 in the PubMed and Web of Science electronic databases. Studies were considered eligible if they included data on the neurobiological mechanisms of appetite regulation or the results of clinical trials of centrally acting drugs in eating disorders. Relevant studies were included regardless of their design. Descriptive analysis was used to summarize the obtained data.

RESULTS

The review included 51 studies. The available neurobiological and clinical data allowed us to identify the following pharmacological strategies for appetite modulation in eating disorders: serotonergic, catecholaminergic, amino acidergic and peptidergic. However, implementation of these data into clinical practice difficult due to an insufficient number of good-quality studies, which is particularly relevant for adolescents as there is a research gap in this population.

CONCLUSION

The progress in neurobiological understanding of the mechanisms of central regulation of appetite opens opportunities for new pharmacotherapeutic approaches aimed at changing the patterns of eating behavior. Obviously, treatment of eating disorders is a much broader problem and cannot be reduced to the correction of eating patterns. Nevertheless, at certain stages of treatment, drug-induced modulation of appetite can play an important role among multi-targeted biological and psychosocial interventions. Translation of neurobiological data into clinical practice requires a large number of clinical studies to confirm the long-term efficacy and safety of pharmacotherapeutic approaches and to develop personalized algorithms for the treatment of various forms of eating disorders in different age groups.

Obtaining long-term recovery: advances in optimizing treatment outcomes in patients with binge-eating disorder

INTRODUCTION

Binge-eating disorder (BED) is a complex and disabling eating disorder (ED) associated with considerable burden and impairments in quality of life and physical/mental health. It has been recognized as a formal ED category since 2013, however BED is still underdetected and undertreated.

AREAS COVERED

This review summarizes the advances in the understanding of the pathophysiology of BED as well as the evidence on the efficacy of the existing treatments. The authors searched Scopus, PubMed, ClinicalTrials.Gov, and ANZCTR with terms including 'assessment' OR 'treatment' OR 'diagnosis' OR 'mechanisms' AND 'binge eating' OR 'binge-eating disorder' for manuscripts published between January 2013 and April 2023.

EXPERT OPINION

Most of the trials on treatments of BED have been in people of high weight with weight loss as an outcome. Nevertheless, less is known about the treatment of this condition in people with body mass index (BMI) within the normal range where weight stabilization may be a more appropriate goal. Moreover, there is a need for an enhanced appreciation of the role of combination treatment to improve overall outcomes. Also, there are important opportunities for future research in understanding the mechanisms of action and effectiveness of BED treatments.

Secondary outcomes and qualitative findings of an open-label feasibility trial of lisdexamfetamine dimesylate for adults with bulimia nervosa

BACKGROUND

There is emerging evidence that stimulants warrant further investigation as a treatment for bulimia nervosa (BN) including a recent open-label feasibility trial examining the use of lisdexamfetamine dimestylate (LDX) for BN. The current report presents the secondary outcomes and qualitative interview results from that feasibility trial. These outcomes explore several purported mechanisms that may explain how stimulants affect symptoms of BN: appetite, impulsivity, obsessive and compulsive symptoms, eating disorder psychopathology/impairment and reward-based decision-making.

METHODS

Twenty-three participants with BN received LDX for eight weeks. Questionnaires assessing appetite, impulsivity, obsessive and compulsive symptoms, eating disorder psychopathology and impairment were administered at baseline and post-treatment. Participants also completed a two-step reinforcement learning task to assess their decision-making. Semi-structured interviews took place at baseline, week 5, and follow-up.

RESULTS

Reductions in hunger, food-related impulsivity, obsessive and compulsive features, eating disorder psychopathology and impairment were found. However, reward learning, as far as it is assessed by the task, did not seem to contribute to the effect of LDX on BN symptoms. Qualitative analysis suggested four themes: (1) reprieve from the eating disorder, (2) improvement in function and quality of life, (3) renewed hope for recovery, and (4) ability to normalize eating.

CONCLUSIONS

This report suggests several potential mechanisms by which LDX may reduce symptoms of binging and purging in those with BN. Importantly, due to the open-label design, we are unable to attribute findings to the medication. Instead, our results should be interpreted as hypothesis generating to inform future studies such as adequately powered randomized controlled trials. Trial registration NCT03397446.

Change in impulsivity is prospectively associated with treatment outcomes for binge-eating disorder

BACKGROUND

Impulsivity may be a process underlying binge-eating disorder (BED) psychopathology and its treatment. This study examined change in impulsivity during cognitive-behavioral therapy (CBT) and/or pharmacological treatment for BED and associations with treatment outcomes.

METHODS

In total, 108 patients with BED (NFEMALE = 84) in a randomized placebo-controlled clinical trial evaluating the efficacy of CBT and/or fluoxetine were assessed before treatment, monthly throughout treatment, at post-treatment (16 weeks), and at 12-month follow-up after completing treatment. Patients completed established measures of impulsivity, eating-disorder psychopathology, and depression, and were measured for height and weight [to calculate body mass index (BMI)] during repeated assessments by trained/monitored doctoral research-clinicians. Mixed-effects models using all available data examined changes in impulsivity and the association of rapid and overall changes in impulsivity on treatment outcomes. Exploratory analyses examined whether baseline impulsivity predicted/moderated outcomes.

RESULTS

Impulsivity declined significantly throughout treatment and follow-up across treatment groups. Rapid change in impulsivity and overall change in impulsivity during treatment were significantly associated with reductions in eating-disorder psychopathology, depression scores, and BMI during treatment and at post-treatment. Overall change in impulsivity during treatment was associated with subsequent reductions in depression scores at 12-month follow-up. Baseline impulsivity did not moderate/predict eating-disorder outcomes or BMI but did predict change in depression scores.

CONCLUSIONS

Rapid and overall reductions in impulsivity during treatment were associated with improvements in specific eating-disorder psychopathology and associated general outcomes. These effects were found for both CBT and pharmacological treatment for BED. Change in impulsivity may be an important process prospectively related to treatment outcome.

Diet quality and eating behaviors of college-attending young adults with food addiction

BACKGROUND

College students are heavily influenced by their food environment and are an important population in which to study food addiction. This mixed-methods study aimed to examine diet quality and eating behaviors of college students with food addiction.

METHODS

Students attending a large university in November 2021 were invited to complete an online survey that measured food addiction, eating styles, eating disorder symptoms, diet quality, and anticipated feelings after eating. Kruskal-Wallis H determined differences between those with and without food addiction in mean scores of quantitative variables. Participants who met the symptom threshold for the presence of food addiction were invited to participate in an interview that elicited more information. Quantitative data was analyzed using JMP Pro Version 16.0 and qualitative data was thematically analyzed using NVIVO Pro Software Version 12.0.

RESULTS

Respondents (n = 1645) had a 21.9 % prevalence of food addiction. Individuals with mild food addiction had the highest scores in cognitive restraint. Those with severe food addiction had the highest scores in uncontrolled eating, emotional eating, and eating disorder symptoms. Individuals with food addiction showed significantly higher negative expectancies for healthy and junk food, lower intake of vegetables, higher intakes of added sugars and saturated fat. Interview participants had problems with sweets and carbohydrates most often and described eating until physically ill, eating in response to negative emotions, dissociation while eating, and strong negative feelings after eating.

CONCLUSION

Findings contribute to the understanding of the behaviors, emotions, and perceptions surrounding food by this population, providing potential behaviors and cognitions to target for treatment.

Effect of stimulant medication on loss of control eating in youth with attention deficit/hyperactivity disorder: a prospective, observational case series study protocol

BACKGROUND

Loss of control eating (LOC-E) in youth predicts the later development of full-syndrome binge-eating disorder (BED), and therefore, could be a relevant target for prevention treatments. To develop these treatments, it is important to understand the underlying disease processes and mechanisms. Based on the putative role of neurocognitive impairments in the pathogenesis of LOC-E, treatments that modulate these neurocognitive factors warrant further exploration. For instance, stimulants are an effective treatment for impulsivity in youth with attention deficit/hyperactivity disorder (ADHD) and have been shown to improve symptoms of BED in adults. Notably, stimulants have not been examined as a treatment for LOC-E in youth. To explore this gap, we aim to measure change in LOC-E episodes and secondary outcomes in youth with comorbid ADHD and LOC-E who are being started on stimulants.

METHODS

We will collect prospective observational data on forty 8-to-13-year-old youth diagnosed with comorbid ADHD and LOC-E who are initiating a stimulant for ADHD. Prior to stimulant initiation, participants will complete baseline measures including LOC-E episode frequency in the last 3 months (primary outcome), and secondary outcomes including disordered eating cognitions, emotions and behaviors, ADHD symptom severity, parental LOC-E, impulsivity and reward sensitivity, and anxiety/mood severity. Outcome measurements will be gathered again at 3-months after initiating the stimulant. Within-patient standardized effect sizes with 95% confidence intervals will be calculated from baseline to 3-month follow-up for all outcomes.

DISCUSSION

Many individuals with LOC-E or binge eating do not fully remit over the course of psychotherapy. Whereas psychotherapy may address psychological and sociocultural domains associated with LOC-E, some individuals with neurocognitive impairments (e.g., ADHD) and neurobiological deficits (e.g., low intrasynaptic dopamine or norepinephrine) may benefit from adjunctive treatment that targets those factors. This will be the first study to provide pilot data for future studies that could examine both the effect of stimulants on LOC-E in youth and underlying mechanisms.

TRIAL REGISTRATION

Trial registration number: NCT05592119.

Psychopharmacologic Management of Eating Disorders

PURPOSE OF REVIEW

Identifying medications that may be used as therapeutic agents for eating disorders is a longstanding focus of research, with varying degrees of success. The present review consolidates the most recent findings on pharmacological treatment of three eating disorders, including anorexia nervosa (AN), bulimia nervosa (BN), and binge eating disorder (BED).

RECENT FINDINGS

Recent research suggests that olanzapine demonstrates positive effects on weight gain among outpatients with AN. There are fewer recent advances in psychopharmacological treatment for BN and BED, likely due to the relative success of prior medication trials. Olanzapine is the first medication to safely promote weight gain among individuals with AN. Fluoxetine is FDA-approved for BN treatment, and lisdexamfetamine is FDA-approved for BED treatment. BN and BED also generally respond well to SSRIs prescribed off-label. Research on psychopharmacological treatments for other eating disorders, such as avoidant-restrictive food intake disorder and other specified feeding and eating disorders, are sorely needed.

Prospects for new drugs to treat binge-eating disorder: Insights from psychopathology and neuropharmacology

BACKGROUND

Binge-eating disorder (BED) is a common psychiatric condition with adverse psychological and metabolic consequences. Lisdexamfetamine (LDX) is the only approved BED drug treatment. New drugs to treat BED are urgently needed.

METHODS

A comprehensive review of published psychopathological, pharmacological and clinical findings.

RESULTS

The evidence supports the hypothesis that BED is an impulse control disorder with similarities to ADHD, including responsiveness to catecholaminergic drugs, for example LDX and dasotraline. The target product profile (TPP) of the ideal BED drug combines treating the psychopathological drivers of the disorder with an independent weight-loss effect. Drugs with proven efficacy in BED have a common pharmacology; they potentiate central noradrenergic and dopaminergic neurotransmission. Because of the overlap between pharmacotherapy in attention deficit hyperactivity disorder (ADHD) and BED, drug-candidates from diverse pharmacological classes, which have already failed in ADHD would also be predicted to fail if tested in BED. The failure in BED trials of drugs with diverse pharmacological mechanisms indicates many possible avenues for drug discovery can probably be discounted.

CONCLUSIONS

(1) The efficacy of drugs for BED is dependent on reducing its core psychopathologies of impulsivity, compulsivity and perseveration and by increasing cognitive control of eating. (2) The analysis revealed a large number of pharmacological mechanisms are unlikely to be productive in the search for effective new BED drugs. (3) The most promising areas for new treatments for BED are drugs, which augment noradrenergic and dopaminergic neurotransmission and/or those which are effective in ADHD.

The potential role of stimulants in treating eating disorders

BACKGROUND

Many individuals with eating disorders remain symptomatic after a course of psychotherapy and pharmacotherapy; therefore, the development of innovative treatments is essential.

METHOD

To learn more about the current evidence for treating eating disorders with stimulants, we searched for original articles and reviews published up to April 29, 2021 in PubMed and MEDLINE using the following search terms: eating disorders, anorexia, bulimia, binge eating, stimulants, amphetamine, lisdexamfetamine, methylphenidate, and phentermine.

RESULTS

We propose that stimulant medications represent a novel avenue for future research based on the following: (a) the relationship between eating disorders and attention deficit/hyperactivity disorder (ADHD); (b) a neurobiological rationale; and (c) the current (but limited) evidence for stimulants as treatments for some eating disorders. Despite the possible benefits of such medications, there are also risks to consider such as medication misuse, adverse cardiovascular events, and reduction of appetite and pathological weight loss. With those risks in mind, we propose several directions for future research including: (a) randomized controlled trials to study stimulant treatment in those with bulimia nervosa (with guidance on strategies to mitigate risk); (b) examining stimulant treatment in conjunction with psychotherapy; (c) investigating the impact of stimulants on "loss of control" eating in youth with ADHD; and (d) exploring relevant neurobiological mechanisms. We also propose specific directions for exploring mediators and moderators in future clinical trials.

DISCUSSION

Although this line of investigation may be viewed as controversial by some in the field, we believe that the topic warrants careful consideration for future research.

The effects of lisdexamfetamine dimesylate on eating behaviour and homeostatic, reward and cognitive processes in women with binge-eating symptoms: an experimental medicine study

Lisdexamfetamine dimesylate (LDX) is the only drug currently approved by the FDA for the treatment of Binge-Eating Disorder (BED), but little is known about the behavioural mechanisms that underpin the efficacy of LDX in treating BED. We examined the behavioural and neural effects of an acute dose of LDX (50 mg) in 22 women with binge-eating symptomatology using a randomised, crossover, double-blind, placebo-controlled experimental medicine design. LDX reduced self-reported appetite ratings and intake of both a pasta meal and a palatable cookie snack. LDX also decreased the eating rate of pasta but not of cookies and reduced self-reported liking ratings for pasta at the end of the meal. When viewing food pictures during an fMRI scan, LDX reduced activity bilaterally in the thalamus. LDX enhanced sustained attention and reduced impulsive responding in a continuous performance task but had no effect on emotional bias or working memory. These results suggest the observed effects of LDX on food intake (and by implication the efficacy of LDX in treating BED) may be related to the actions of the drug to enhance satiety, reduce food-related reward responding when full and/or increase cognitive control. Novel pharmacotherapies for BED might be most effective if they have a broad spectrum of effects on appetite, reward and cognition.

What pharmacological interventions are effective in binge-eating disorder? Insights from a critical evaluation of the evidence from clinical trials

Binge-eating disorder (BED) is the commonest eating disorder and an important causal factor in obesity. Lisdexamfetamine is the only approved pharmacological treatment. Many drugs have been clinically evaluated and several were described as potentially promising treatments. A comprehensive reassessment of the evidence from these clinical trials has been performed. The questions to be answered were: (1) Does the evidence support claims of efficacy? (2) What pharmacological mechanisms show promise for developing new BED drugs? (3) What are the clinical implications for treating BED? PubMed and internal database searches identified every available published drug trial in BED. The trials and their results were summarised and reviewed to re-evaluate the evidence. Factors taken into consideration included psychiatric diagnosis, primary endpoint, secondary outcome measures, trial size, blinding and controls, drop-out rates, placebo response rates and weight-loss. Drugs were classified according to their pharmacology and therapeutic indication to determine which mechanisms were effective and to provide insights into the psychopathology of BED. For most drugs, robust evidence of efficacy in BED is insubstantial or absent. Some catecholaminergic drugs developed for ADHD are also effective in BED; other pharmacological mechanisms are weakly efficacious at best. Reducing BED severity has little impact on weight. Conversely, weight-loss from anti-obesity therapy is ineffective in ameliorating the psychopathological drivers of BED. (1) BED is a psychiatric not a metabolic disorder. (2) Weight-loss drugs are generally ineffective in BED. (3) Efficacy in BED is restricted to powerful catecholaminergic drugs. (4) Drugs acting via noradrenaline, 5-HT, GABA, carbonic anhydrase inhibition, opioid receptors and various ion channels are generally minimally effective at best. (5) Efficacy in BED is dependent on treating its core psychopathology; reducing impulsivity and compulsivity and increasing cognitive restraint over eating. (6) Obese subjects with BED may benefit from separate treatments for these two disorders.

New Drugs to Treat ADHD: Opportunities and Challenges in Research and Development

Since the landmark MTA (Multimodal Treatment of ADHD) trial unequivocally demonstrated the efficacy of methylphenidate, catecholaminergic drugs, especially stimulants, have been the therapeutic mainstay in treatment of Attention-Deficit Hyperactivity Disorder (ADHD). We review the new drugs which have entered the ADHD formulary. The lessons learned from drug-candidates that have succeeded in clinical trials together with those that have not have also been considered. What emerges confirms and consolidates the hypothesis that clinically effective ADHD drugs indirectly or directly increase catecholaminergic neurotransmission in the prefrontal cortex (PFC). Attempts to enhance catecholaminergic signalling through modulatory neurotransmitter systems or cognitive-enhancing drugs have all failed. New drugs approved for ADHD are catecholaminergic reuptake inhibitors and releasing agents, or selective noradrenaline reuptake inhibitors. Triple reuptake inhibitors with preferential effects on dopamine have not been successful. The substantial number of failures probably accounts for a continued focus on developing novel catecholaminergic and noradrenergic drugs, and a dearth of drug-candidates with novel mechanisms entering clinical development. However, substantial improvements in ADHD pharmacotherapy have been achieved by the almost exclusive use of once-daily medications and prodrugs, e.g. lisdexamfetamine and Azstarys^®, which improve compliance, deliver greater efficacy and reduce risks for diversion and abuse.

Lisdexamfetamine and binge-eating disorder: A systematic review and meta-analysis of the preclinical and clinical data with a focus on mechanism of drug action in treating the disorder

Binge-Eating Disorder (BED) is the most common eating disorder in the United States. Lisdexamfetamine (LDX) was approved in 2015 by the FDA for treatment of BED and is the only drug approved for treating the disorder. There has been no systematic evaluation of the published clinical and preclinical evidence for efficacy of LDX in treating BED and the mechanisms responsible for the therapeutic action of the drug. To address this gap, we conducted a systematic review and meta-analysis using PRISMA guidelines. Fourteen clinical and seven preclinical articles were included. There is consistent evidence from clinical studies that LDX is an effective treatment for BED and that the drug reduces the BED symptoms and body weight of patients with the disorder. There is also consistent evidence from preclinical studies that LDX reduces food intake but no consistent evidence for a preferential reduction of palatable food consumption by the drug in rodents. The evidence on mechanism of action is more limited and suggests LDX may reduce binge eating by a combination of effects on appetite/satiety, reward, and cognitive processes, including attention and impulsivity/inhibition, that are mediated by catecholamine and serotonin mechanisms in the brain. There is an urgent need for adequately powered, placebo-controlled, behavioural and neuroimaging studies with LDX (recruiting patients and/or individuals with subclinical BED symptoms) to further investigate the mechanism of action of the drug in treating BED. An improved understanding of the behavioural and neurochemical mechanisms of action of LDX could lead to the development of improved drug therapies to treat BED.

General impulsivity in binge-eating disorder

BACKGROUND

The nature and significance of impulse-control difficulties in binge-eating disorder (BED) are uncertain. Most emerging research has focused on food-specific rather than general impulsivity. The current study examines the clinical presentation of patients with BED categorized with and without clinical levels of general impulsivity.

METHOD

A total of 343 consecutive treatment-seeking patients with BED were categorized as having BED with general impulsivity (GI+; N = 73) or BED without general impulsivity (GI-: N = 270) based on structured diagnostic and clinical interviews. The groups were compared on demographic, developmental, and psychological features, and on rates of psychiatric and personality comorbidity.

RESULTS

Individuals with BED and general impulsivity (GI+) reported greater severity of eating-disorder psychopathology, greater depressive symptoms, and greater rates of comorbidity than those without general impulsivity (GI-).

CONCLUSIONS

A subtype of individuals with BED and general impulsivity may signal a more severe presentation of BED characterized by heightened and broader psychopathology. Future work should investigate whether these impulse-control difficulties relate to treatment outcomes.

Impulsivity and Its Relationship With Lisdexamfetamine Dimesylate Treatment in Binge Eating Disorder

High trait impulsivity is thought to contribute to the sense of loss of control over eating and impulses to binge eat experienced by those with binge eating disorder (BED). Lisdexamfetamine dimesylate (LDX), a drug approved for treatment of moderate to severe BED, has been shown to decrease impulsive features of BED. However, the relationship between LDX-related reductions of binge eating (BE) episodes and impulsivity has not yet been explored. Forty-one adults aged 18-40years with moderate to severe BED completed questionnaires and tasks assessing impulsivity at baseline and after 8weeks of 50-70mg of LDX. Twenty age-matched healthy controls were also assessed at two timepoints for normative comparison. Data were analysed using linear mixed models. BED participants exhibited increased self-reported motor, non-planning, cognitive and food-related impulsivity relative to controls but no differences in objective task-based measures of impulsivity. Food-related and non-planning impulsivity was significantly reduced by LDX, but not to normative levels. Individuals with higher baseline levels of motor and non-planning impulsivity, and loss of control over eating scores experienced the greatest reduction in BE frequency after 8weeks of LDX. Further, there were significant associations between the degree to which subjective loss of control over eating, non-planning impulsivity and BE frequency reduced after 8weeks of LDX. These data suggest that specific subjective measures of impulsivity may be able to predict who will have the greatest benefit from LDX treatment and that reductions in BE frequency may be moderated by concurrent reductions in non-planning impulsivity.

Aversion to Off-label Prescribing in Clinical Pediatric Weight Management: The Quintessential Double Standard

CONTEXT

Pediatric obesity is now recognized as a chronic disease; yet few treatment options exist besides lifestyle modification therapy and bariatric surgery. We describe the limited availability of United States Food and Drug Administration (FDA)-approved antiobesity medications for adolescents and compare this to what is available for adults. We offer a rationale for off-label prescribing to assist with lifestyle modification therapy. We also highlight the need for more pharmacotherapy options and additional research into novel treatments for pediatric obesity.

CASE DESCRIPTION

We describe a patient who is struggling with managing her weight and starting to develop complications of obesity. We offer a framework in which off-label prescribing may be beneficial to patients who have been engaging in lifestyle modification therapy yet fail to see improvement.

CONCLUSION

Lifestyle modification therapy is necessary but often insufficient in stimulating clinically meaningful weight loss when used alone in children and adolescents who struggle with weight management. Until more FDA-approved antiobesity medications are available, pediatricians may be able to help more patients achieve weight reduction goals by familiarizing themselves with the responsible use of off-label medications and implementing these tools to improve clinical outcomes. There is a critical need for more pharmacotherapy options to help pediatric patients in managing their weight and preventing or improving the insidious complications resulting from untreated obesity.

Converging vulnerability factors for compulsive food and drug use

Highly palatable foods and substance of abuse have intersecting neurobiological, metabolic and behavioral effects relevant for understanding vulnerability to conditions related to food (e.g., obesity, binge eating disorder) and drug (e.g., substance use disorder) misuse. Here, we review data from animal models, clinical populations and epidemiological evidence in behavioral, genetic, pathophysiologic and therapeutic domains. Results suggest that consumption of highly palatable food and drugs of abuse both impact and conversely are regulated by metabolic hormones and metabolic status. Palatable foods high in fat and/or sugar can elicit adaptation in brain reward and withdrawal circuitry akin to substances of abuse. Intake of or withdrawal from palatable food can impact behavioral sensitivity to drugs of abuse and vice versa. A robust literature suggests common substrates and roles for negative reinforcement, negative affect, negative urgency, and impulse control deficits, with both highly palatable foods and substances of abuse. Candidate genetic risk loci shared by obesity and alcohol use disorders have been identified in molecules classically associated with both metabolic and motivational functions. Finally, certain drugs may have overlapping therapeutic potential to treat obesity, diabetes, binge-related eating disorders and substance use disorders. Taken together, data are consistent with the hypotheses that compulsive food and substance use share overlapping, interacting substrates at neurobiological and metabolic levels and that motivated behavior associated with feeding or substance use might constitute vulnerability factors for one another. This article is part of the special issue on 'Vulnerabilities to Substance Abuse'.

The Neurobiology of Binge-eating Disorder Compared with Obesity: Implications for Differential Therapeutics

PURPOSE

Emerging work indicates divergence in the neurobiologies of binge-eating disorder (BED) and obesity despite their frequent co-occurrence. This review highlights specific distinguishing aspects of BED, including elevated impulsivity and compulsivity possibly involving the mesocorticolimbic dopamine system, and discusses implications for differential therapeutics for BED.

METHODS

This narrative review describes epidemiologic, clinical, genetic, and preclinical differences between BED and obesity. Subsequently, this review discusses human neuroimaging work reporting differences in executive functioning, reward processing, and emotion reactivity in BED compared with obesity. Finally, on the basis of the neurobiology of BED, this review identifies existing and new therapeutic agents that may be most promising given their specific targets based on putative mechanisms of action relevant specifically to BED.

FINDINGS

BED is characterized by elevated impulsivity and compulsivity compared with obesity, which is reflected in divergent neurobiological characteristics and effective pharmacotherapies. Therapeutic agents that influence both reward and executive function systems may be especially effective for BED.

IMPLICATIONS

Greater attention to impulsivity/compulsivity-related, reward-related, and emotion reactivity-related processes may enhance conceptualization and treatment approaches for patients with BED. Consideration of these distinguishing characteristics and processes could have implications for more targeted pharmacologic treatment research and interventions.

A Group Intervention for Individuals With Obesity and Comorbid Binge Eating Disorder: Results From a Feasibility Study

PURPOSE

A common challenge among a subgroup of individuals with obesity is binge eating, that exists on a continuum from mild binge eating episodes to severe binge eating disorder (BED). BED is common among bariatric patients and the prevalence of disordered eating and ED in bariatric surgery populations is well known. Conventional treatments and assessment of obesity seldom address the underlying psychological mechanisms of binge eating and subsequent obesity. This study, titled PnP (People need People) is a psychoeducational group pilot intervention for individuals with BED and obesity including patients with previous bariatric surgery. Design, feasibility, and a broad description of the study population is reported.

MATERIAL AND METHODS

A total of 42 patients were from an obesity clinic referred to assessment and treatment with PnP in a psychoeducational group setting (3-hour weekly meetings for 10 weeks). Of these, 6 (14.3%) patients had a previous history of bariatric surgery. Feasibility was assessed by tracking attendance, potentially adverse effects and outcome measures including body mass index (BMI), eating disorder pathology, overvaluation of shape and weight, impairment, self-reported childhood difficulties, alexithymia, internalized shame as well as health related quality of life (HRQoL).

RESULTS

All 42 patients completed the intervention, with no adverse effects and a high attendance rate with a median attendance of 10 sessions, 95% CI (8.9,9.6) and 0% attrition. Extent of psychosocial impairment due to eating disorder pathology, body dissatisfaction and severity of ED symptoms were high among the patients at baseline. Additionally, self-reported childhood difficulties, alexithymia, and internalized shame were high among the patients and indicate a need to address underlying psychological mechanisms in individuals with BED and comorbid obesity. Improvement of HRQoL and reduction of binge eating between baseline and the end of the intervention was observed with a medium effect.

CONCLUSION

This feasibility study supports PnP as a potential group psychoeducational intervention for patients living with BED and comorbid obesity. Assessments of BED and delivery of this intervention may optimize selection of candidates and bariatric outcomes. These preliminary results warrant further investigation via a randomized control trial (RCT) to examine the efficacy and effectiveness of PnP.

Binge Eating Disorder: A Psychiatrist's Commentary on Clinical Considerations

PURPOSE

Of the 3 major eating disorders, anorexia nervosa, bulimia nervosa, and binge eating disorder (BED), BED is the most common and exists in the practices of most primary care and psychiatric clinicians. However, BED often goes unrecognized and thus untreated.

METHODS

Reviewed in this commentary are the basic elements in the diagnosis of BED, demographic and clinical characteristics, screening options, the importance of comorbidities, pathophysiology, and available treatments.

FINDINGS

Psychological treatments, including cognitive-behavioral therapy, interpersonal therapy, and behavioral weight loss, have been recommended as first-line options and are supported by several different meta-analytic reviews. Lisdexamfetamine is currently the only medication approved by the US Food and Drug Administration for the treatment of BED. Effect sizes for lisdexamfetamine versus placebo for response, remission, and avoidance of relapse in BED are robust, but its use may be limited by tolerability. This is also the case for topiramate, an anticonvulsant that has been used "off-label" to treat BED.

IMPLICATIONS

Additional medication choices approved by the US Food and Drug Administration for the treatment of BED are needed. Moving forward, opportunities to leverage modern technology to broaden access to treatment are highly desirable.

A review of binge eating disorder and obesity

Binge eating disorder (BED) is a mental illness characterised by recurrent binge eating episodes in the absence of appropriate compensatory behaviours. Consequently, BED is strongly associated with obesity. The current review aims to provide an update of the most relevant aspects of BED (e.g., clinical profile, aetiology and treatment approaches), in order not only to facilitate a better understanding of the disorder and its clinical consequences, but also to identify potential targets of prevention and intervention. Patients with BED often present high comorbidity with other medical conditions and psychiatric disorders. Numerous risk factors have been associated with the development and maintenance of the disorder. Moreover, although some treatments for BED have proven to be effective in addressing different key aspects of the disorder, the rates of patients that have ever received specific treatment for BED are very low. The factors involved and how to implement effective treatments will be discussed for the purpose of addressing the eating symptomatology and comorbid obesity.

Regulation of adenosine A2A receptor gene expression in a model of binge eating in the amygdaloid complex of female rats

BACKGROUND

Pharmacological treatment approaches for eating disorders, such as binge eating disorder and bulimia nervosa, are currently limited.

METHODS AND AIMS

Using a well-characterized animal model of binge eating, we investigated the epigenetic regulation of the A_2A Adenosine Receptor (A_2AAR) and dopaminergic D2 receptor (D2R) genes.

RESULTS

Gene expression analysis revealed a selective increase of both receptor mRNAs in the amygdaloid complex of stressed and restricted rats, which exhibited binge-like eating, when compared to non-stressed and non-restricted rats. Consistently, pyrosequencing analysis revealed a significant reduction of the percentage of DNA methylation but only at the A_2AAR promoter region in rats showing binge-like behaviour compared to the control animals. Focusing thus on A_2AAR agonist (VT 7) administration (which inhibited the episode of binge systemically at 0.1 mg/kg or intra-central amygdala (CeA) injection at 900 ng/side) induced a significant increase of A_2AAR mRNA levels in restricted and stressed rats when compared to the control group. In addition, we observed a significant decrease in A_2AAR mRNA levels in rats treated with the A_2AAR antagonist (ANR 94) at 1 mg/kg. Consistent changes in the DNA methylation status of the A_2AAR promoter were found in restricted and stressed rats after administration of VT 7 or ANR 94.

CONCLUSION

We confirm the role of A_2AAR in binge eating behaviours, and we underline the importance of epigenetic regulation of the A_2AAR gene, possibly due to a compensatory mechanism to counteract the effect of binge eating. We suggest that A_2AAR activation, inducing receptor gene up-regulation, could be relevant to reduction of food consumption.

Eating disorder animal model

PURPOSE OF REVIEW

The aim of this review is to describe animal models that simulate the features of eating disorders. The literature pertaining to animal models that are of relevance for clinical eating disorders and the possible underpinning mechanisms was reviewed using PubMed, Ovid database and Google Scholar.

RECENT FINDINGS

New refinements of the circuits regulated by neurotransmitters and neuropeptides which instigate eating behaviours and the various feedback pathways which monitor acute and chronic nutrient status continue to be discovered. Moreover, work with the animal models that simulate the behavioural features and risk factors related to eating disorders is flourishing and providing new insights into possible causal mechanisms. For example, rodents develop binge-eating behaviours if they are intermittently exposed to processed, palatable foods and/or sugar adulterated drinks. This led to the controversial conceptualization of binge eating as a form of food addiction. Self-starvation taken to a fatal consequence such as occurs in anorexia nervosa can emerge in rodents exposed to triggers like social exclusion and/or the opportunity to exercise.

SUMMARY

There are plausible animal models for both anorexia nervosa and binge-eating disorders. These can be used to elaborate the theoretical models to explain the mechanisms underpinning eating disorders.

Toward an understanding of the distinctiveness of body-image constructs in persons categorized with overweight/obesity, bulimia nervosa, and binge-eating disorder

OBJECTIVE

We examined distinctiveness of different aspects of body-image disturbance in persons categorized with eating/weight disorders. We compared dissatisfaction with weight/shape, overvaluation of weight/shape, preoccupation with weight/shape, and fear of weight gain - in three study groups of persons categorized with overweight/obesity [O/O], bulimia nervosa [BN], and binge-eating disorder [BED] and examined how each body-image construct relates to clinical measures within and between the study groups.

METHOD

1017 community volunteers completed measures of body-image, eating-disorder psychopathology, and depression. Participants were categorized into three study groups: O/O (N = 511), BN-purging type (N = 167), and BED (N = 339).

RESULTS

Groups differed significantly on the four body-image constructs (medium-to-large effect sizes) with a consistent severity gradient with BN greater than BED greater than O/O. Both within and between groups, the four body-image constructs varied in strengths of association among themselves and with clinical measures. Analyses revealed considerable variability in variance accounted for in the clinical measures; distinctive significant patterns observed across the groups included: dissatisfaction with BMI, preoccupation and fear with eating concerns and restraint, and overvaluation with depression.

CONCLUSION

Clinical manifestations of body-image disturbances are complex and show important differences across study groups defined as overweight/obesity, BN, and BED. Improved understanding of distinctions between different body-image constructs and their differential salience across different eating/weight disorders is needed to improve case conceptualization and treatment formulation.

Convergent neural connectivity in motor impulsivity and high-fat food binge-like eating in male Sprague-Dawley rats

Food intake is essential for survival, but maladaptive patterns of intake, possibly encoded by a preexisting vulnerability coupled with the influence of environmental variables, can modify the reward value of food. Impulsivity, a predisposition toward rapid unplanned reactions to stimuli, is one of the multifaceted determinants underlying the etiology of dysregulated eating and its evolving pathogenesis. The medial prefrontal cortex (mPFC) is a major neural director of reward-driven behavior and impulsivity. Compromised signaling between the mPFC and nucleus accumbens shell (NAcSh) is thought to underlie the cognitive inability to withhold prepotent responses (motor impulsivity) and binge intake of high-fat food (HFF) seen in binge eating disorder. To explore the relationship between motor impulsivity and binge-like eating in rodents, we identified high (HI) and low impulsive (LI) rats in the 1-choice serial reaction time task and employed a rat model of binge-like eating behavior. HFF binge rats consumed significantly greater calories relative to control rats maintained on continual access to standard food or HFF. HI rats repeatedly exhibited significantly higher bingeing on HFF vs. LI rats. Next, we employed dual viral vector chemogenetic technology which allows for the targeted and isolated modulation of ventral mPFC (vmPFC) neurons that project to the NAcSh. Chemogenetic activation of the vmPFC to NAcSh pathway significantly suppressed motor impulsivity and binge-like intake for high-fat food. Thus, inherent motor impulsivity and binge-like eating are linked and the vmPFC to NAcSh pathway serves as a 'brake' over both behaviors.

A randomized comparison of long acting methylphenidate and cognitive behavioral therapy in the treatment of binge eating disorder

Cognitive behavioral therapy (CBT) is a well-established treatment for binge eating disorder (BED); however, this treatment is underutilized, highlighting the need for additional treatment alternatives. Dopamine neurotransmission has been associated with dysregulated eating, and pharmaceutical agents targeting the dopamine system are associated with decreased binge eating and weight. The primary objective of the current investigation was to evaluate the efficacy of psychostimulant medication versus current best practices in the treatment of BED symptoms, in a randomized trial of methylphenidate versus CBT for BED. The secondary objective was to evaluate the ability of impulsivity to predict treatment outcomes. Female outpatients with BED were randomized to receive methylphenidate (n = 22) or CBT (n = 27) for 12 weeks. The primary outcome was objective binge episode frequency; secondary outcomes included subjective binge episode frequency, body mass index (BMI), BED symptoms, and quality of life. Results showed that both treatments had a significant impact on primary and secondary outcomes. Methylphenidate and CBT were associated with decreases in subjective and objective binge episodes; methylphenidate was associated with greater decreases in BMI. Two impulsivity traits predicted clinical outcomes. Results provide preliminary support for the therapeutic benefit of methylphenidate in BED treatment, and prognostic utility of impulsivity in this context.

Neuropharmacology of compulsive eating

Compulsive eating behaviour is a transdiagnostic construct observed in certain forms of obesity and eating disorders, as well as in the proposed construct of 'food addiction'. Compulsive eating can be conceptualized as comprising three elements: (i) habitual overeating, (ii) overeating to relieve a negative emotional state, and (iii) overeating despite adverse consequences. Neurobiological processes that include maladaptive habit formation, the emergence of a negative affect, and dysfunctions in inhibitory control are thought to drive the development and persistence of compulsive eating behaviour. These complex psychobehavioural processes are under the control of various neuropharmacological systems. Here, we describe the current evidence implicating these systems in compulsive eating behaviour, and contextualize them within the three elements. A better understanding of the neuropharmacological substrates of compulsive eating behaviour has the potential to significantly advance the pharmacotherapy for feeding-related pathologies.This article is part of a discussion meeting issue 'Of mice and mental health: facilitating dialogue between basic and clinical neuroscientists'.

Understanding the neural mechanisms of lisdexamfetamine dimesylate (LDX) pharmacotherapy in Binge Eating Disorder (BED): a study protocol

BACKGROUND

The efficacy and safety of Lisdexamfetamine dimesylate (LDX) in the treatment of moderate to severe binge eating disorder (BED) has been demonstrated in multiple randomised clinical trials. Despite this, little is known about how LDX acts to improve binge eating symptoms. This study aims to provide a comprehensive understanding of the neural mechanisms by which LDX improves symptoms of BED. We hypothesise that LDX will act by normalising connectivity within neural circuits responsible for reward and impulse control, and that this normalisation will correlate with reduced binge eating episodes.

METHODS

This is an open-label Phase 4 clinical trial of LDX in adults with moderate to severe BED. Enrolment will include 40 adults with moderate to severe BED aged 18-40 years and Body Mass Index (BMI) of 20-45 kg/m², and 22 healthy controls matched for age, gender and BMI. Clinical interview and validated scales are used to confirm diagnosis and screen for exclusion criteria, which include comorbid anorexia nervosa or bulimia nervosa, use of psychostimulants within the past 6 months, and current use of antipsychotics or noradrenaline reuptake inhibitors. Baseline assessments include clinical symptoms, multimodal neuroimaging, cognitive assessment of reward sensitivity and behavioural inhibition, and an (optional) genetic sample. A subset of these assessments are repeated after eight weeks of treatment with LDX titrated to either 50 or 70 mg. The primary outcome measures are resting-state intrinsic connectivity and the number of binge eating episodes. Analyses will be applied to resting-state fMRI data to characterise pharmacological effects across the functional connectome, and assess correlations with symptom measure changes. Comparison of neural measures between controls and those with BED post-treatment will also be performed to determine whether LDX normalises brain function.

DISCUSSION

First enrolment was in May 2018, and is ongoing. This study is the first comprehensive investigation of the neurobiological changes that occur with LDX treatment in adults with moderate to severe BED.

TRIAL REGISTRATION

ACTRN12618000623291, Australian and New Zealand Clinical Trials Registry URL: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=374913&isReview=true. Date of Registration: 20 April 2018.

Form and formulation: Examining the distinctiveness of body image constructs in treatment-seeking patients with binge-eating disorder

OBJECTIVE

Body-image disturbance is a core aspect of eating disorders, yet the clinical manifestations of individuals' weight and shape concerns are complex, vary considerably, and are poorly understood by clinicians and researchers. This study aimed to distinguish different aspects of body-image disturbance-including weight/shape dissatisfaction, weight/shape overvaluation, weight/shape preoccupation, and fear of weight gain-in patients with binge-eating disorder (BED). Examining how each specific body image construct relates to biopsychosocial features of BED could contribute to the refinement of conceptualization and treatment planning.

METHOD

The current study assessed body-image disturbance and eating-disorder psychopathology in 748 treatment-seeking patients with BED using established investigator-based interviews reliably administered by doctoral clinicians.

RESULTS

The 4 body image constructs, although related to one another, showed some important similarities in associations with biopsychosocial clinical features, as well as some important distinctions. The relation between overvaluation and self-esteem was, as conceptualized, more strongly negative than for other body image variables, and preoccupation was more associated than other body image variables with eating concerns. Biopsychosocial features of BED were associated with different forms of body-image disturbance, but associations of body image variables with body mass index (BMI) were not significant and associations with binge-eating frequency did not differ across body image variables.

CONCLUSION

Manifestations of body-image disturbance in BED are complex and understanding the distinctions between different body image constructs can contribute to treatment formulation. (PsycINFO Database Record

Relationships between clinical scales and binge eating days in adults with moderate to severe binge eating disorder in two Phase III studies

OBJECTIVES

In two Phase III studies, lisdexamfetamine dimesylate (LDX) reduced binge eating (BE) days/week in adults with moderate to severe binge eating disorder (BED) and was associated with improvement based on the Clinical Global Impressions-Improvement (CGI-I) scale. In this study, post hoc analyses examined the relationships between clinical observations and clinical rating scales in individuals with BED.

CLINICAL TRIAL REGISTRATION

NCT01718483 (ClinicalTrials.gov/ct2/show/NCT01718483); NCT01718509 (ClinicalTrials.gov/ct2/show/NCT01718509).

METHODS

Two 12-week, double-blind, placebo-controlled studies randomized (1:1) adults meeting Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision, BED criteria and with protocol-defined moderate to severe BED (study 1, N=383; study 2, N=390) to placebo or dose-optimized LDX (50 or 70 mg). Assessments included the number of BE days/week, CGI-Severity (CGI-S) and CGI-I scores, and Yale-Brown Obsessive Compulsive Scale modified for Binge Eating (Y-BOCS-BE) total scores. For these post hoc analyses, data were pooled across studies and treatment arms. Statistical assessments included Spearman correlations and equipercentile linking analyses (ELA). Reported P-values are nominal (descriptive and not adjusted for multiplicity).

RESULTS

At baseline, nominally significant correlations with CGI-S scores were reported for BE days/week (r=0.374; P<0.0001) and Y-BOCS-BE total scores (r=0.319; P<0.0001). Baseline ELA for CGI-S further characterized this relationship: a CGI-S score of 4 (moderately ill) corresponding to 3.504 BE days/week and a Y-BOCS-BE total score of 18.6. Nominally significant correlations with CGI-I scores were reported for changes from baseline at study endpoint for BE days/week (r=0.647; P<0.0001) and Y-BOCS-BE total scores (r=0.741; P<0.0001). ELA for CGI-I scores at study endpoint showed that a CGI-I score of 1 (very much improved) corresponds to a reduction from baseline of 4.504 BE days/week and 19.4 points for Y-BOCS-BE total score.

CONCLUSION

These post hoc analyses suggest that indices of global disease severity and improvement positively correlate with BE behavior and with obsessive and compulsive features of BED, measured by the Y-BOCS-BE, supporting the clinical relevance of BED treatment outcomes.

A narrative review of potential treatment strategies for food addiction

The concept of food addiction (FA) remains controversial with research being in the nascent stages; FA like any addiction can have a devastating impact on the lives of those afflicted. There exists a clinical need for treatment strategies for those affected. This article reviews potential treatment strategies for FA. The treatment strategies target four core behaviours of the addiction phenotype specifically craving through the opioid system, impulsivity as a personality trait, compulsivity through the serotonergic system and lastly motivation through the dopaminergic system. A range of pharmacological and psychological interventions are reviewed. Future research should seek to test and validate the proposed clinical treatment strategies.

Binge-eating disorder: Clinical and therapeutic advances

Binge-eating disorder (BED) is the most prevalent eating disorder with estimates of 2-5% of the general adult population. Nonetheless, its pathophysiology is poorly understood. Furthermore, there exist few therapeutic options for its effective treatment. Here we review the current state of binge-eating neurobiology and pharmacology, drawing from clinical therapeutic, neuroimaging, cognitive, human genetic and animal model studies. These studies, which are still in their infancy, indicate that while there are many gaps in our knowledge, several key neural substrates appear to underpin binge-eating and may be conserved between human and animals. This observation suggests that behavioral intermediate phenotypes or endophenotypes relevant to BED may be modeled in animals, facilitating the identification and testing of novel pharmacological targets. The development of novel, safe and effective pharmacological therapies for the treatment of BED will enhance the ability of clinicians to provide optimal care for people with BED.

Emerging Treatments in Eating Disorders

Eating disorders (EDs), including anorexia nervosa, bulimia nervosa, and binge-eating disorder, constitute a class of common and deadly psychiatric disorders. While numerous studies in humans highlight the important role of neurobiological alterations in the development of ED-related behaviors, the precise neural substrate that mediates this risk is unknown. Historically, pharmacological interventions have played a limited role in the treatment of eating disorders, typically providing symptomatic relief of comorbid psychiatric issues, like depression and anxiety, in support of the standard nutritional and psychological treatments. To date there are no Food and Drug Administration-approved medications or procedures for anorexia nervosa, and only one Food and Drug Administration-approved medication each for bulimia nervosa (fluoxetine) and binge-eating disorder (lisdexamfetamine). While there is little primary interest in drug development for eating disorders, postmarket monitoring of medications and procedures approved for other indications has identified several novel treatment options for patients with eating disorders. In this review, I utilize searches of the PubMed and ClinicalTrials.gov databases to highlight emerging treatments in eating disorders.

Dopamine and μ-opioid receptor dysregulation in the brains of binge-eating female rats - possible relevance in the psychopathology and treatment of binge-eating disorder

Adult, female rats given irregular, limited access to chocolate develop binge-eating behaviour with normal bodyweight and compulsive/perseverative and impulsive behaviours similar to those in binge-eating disorder. We investigated whether (a) dysregulated central nervous system dopaminergic and opioidergic systems are part of the psychopathology of binge-eating and (b) these neurotransmitter systems may mediate the actions of drugs ameliorating binge-eating disorder psychopathology. Binge-eating produced a 39% reduction of striatal D₁ receptors with 22% and 23% reductions in medial and lateral caudate putamen and a 22% increase of striatal μ-opioid receptors. There was no change in D₁ receptor density in nucleus accumbens, medial prefrontal cortex or dorsolateral frontal cortex, striatal D₂ receptors and dopamine reuptake transporter sites, or μ-opioid receptors in frontal cortex. There were no changes in ligand affinities. The concentrations of monoamines, metabolites and estimates of dopamine (dopamine/dihydroxyphenylacetic acid ratio) and serotonin/5-hydroxyindolacetic acid ratio turnover rates were unchanged in striatum and frontal cortex. However, turnover of dopamine and serotonin in the hypothalamus was increased ~20% and ~15%, respectively. Striatal transmission via D₁ receptors is decreased in binge-eating rats while μ-opioid receptor signalling may be increased. These changes are consistent with the attenuation of binge-eating by lisdexamfetamine, which increases catecholaminergic neurotransmission, and nalmefene, a μ-opioid antagonist.

Investigation of impulsivity in binge-eating rats in a delay-discounting task and its prevention by the d-amphetamine prodrug, lisdexamfetamine

Freely-fed, female, rats were trained in a two-lever, delay-discounting task: one lever delivered a single chocolate-flavoured pellet immediately and the other a three-pellet reward after increasing delay (0, 4, 8, 16, 32 s). Rats were divided into two groups (i.e. binge-eating rats given irregular, limited access to chocolate in addition to normal chow and controls maintained on normal chow). Both groups exhibited increased preference for the immediate reward as the delay interval was lengthened. The discounting rate was significantly greater in binge-eating rats than non-binge-eating controls, especially as the behaviour became more established indicating that increased impulsivity and intolerance of delayed reward are part of the psychopathology of binge-eating. Lisdexamfetamine (0.8 mg/kg, orally ( d-amphetamine base)) reversed the reduced preference of binge-eating rats for larger rewards at delay intervals of 4 s, 8 s and 32 s and across all sessions. Lisdexamfetamine-treated binge-eating rats consumed the same number of pellets as vehicle-treated, binge-eating rats and non-binge-eating controls eliminating the possibility lisdexamfetamine's actions on appetite or satiety mediated its effects on operant responding for food pellets in delay-discounting. In summary, binge-eating rats showed increased impulsive choice compared with non-binge-eating controls that was reversed by lisdexamfetamine, complementing results showing lisdexamfetamine reduced impulsiveness scores in patients with binge-eating disorder.

Lisdexamfetamine reduces the compulsive and perseverative behaviour of binge-eating rats in a novel food reward/punished responding conflict model

Compulsive and perseverative behaviour in binge-eating, female, Wistar rats was investigated in a novel food reward/punished responding conflict model. Rats were trained to perform the conditioned avoidance response task. When proficient, the paradigm was altered to a food-associated conflict test by placing a chocolate-filled jar (empty jar for controls) in one compartment of the shuttle box. Entry into the compartment with the jar triggered the conditioning stimulus after a variable interval, and foot-shock 10 seconds later if the rat did not leave. Residence in the 'safe' compartment with no jar did not initiate trials or foot-shocks. By frequently entering the chocolate-paired compartment, binge-eating rats completed their 10 trials more quickly than non-binge controls. Binge-eating rats spent a greater percentage of the session in the chocolate-paired compartment, received foot-shocks more frequently, and tolerated foot-shocks for longer periods; all consistent with compulsive and perseverative behaviour. The d-amphetamine prodrug, lisdexamfetamine, has recently received US approval for the treatment of moderate to severe binge-eating disorder in adults. Lisdexamfetamine (0.8 mg/kg po [d-amphetamine base]) decreased chocolate consumption by binge-eating rats by 55% and markedly reduced compulsive and perseverative responding in the model. These findings complement clinical results showing lisdexamfetamine reduced compulsiveness scores in subjects with binge-eating disorder.

Novel pharmacologic treatment in acute binge eating disorder - role of lisdexamfetamine

Binge eating disorder (BED) is the most common eating disorder and an important public health problem. It is characterized by recurrent episodes of excessive food consumption accompanied by a sense of loss of control over the binge eating behavior without the inappropriate compensatory weight loss behaviors of bulimia nervosa. BED affects both sexes and all age groups and is associated with medical and psychiatric comorbidities. Until recently, self-help and psychotherapy were the primary treatment options for patients with BED. In early 2015, lisdexamfetamine dimesylate, a prodrug stimulant marketed for attention deficit hyperactive disorder, was the first pharmacologic agent to be approved by the US Food and Drug Administration for the treatment of moderate or severe BED in adults. This article summarizes BED clinical presentation, and discusses the pharmacokinetic profile, efficacy, and safety of lisdexamfetamine dimesylate in the treatment of BED in adults.