Olanzapine-induced weight gain in anorexia nervosa: involvement of leptin and ghrelin secretion?

Psychopharmacology of eating disorders: Systematic review and meta-analysis of randomized controlled trials

BACKGROUND

The concurrent assessment of weight and affective psychopathology outcomes relevant to the psychopharmacology of major eating disorders (EDs), namely anorexia nervosa (AN), bulimia nervosa (BN), and binge eating disorder (BED), warrants systematic review and meta-analysis of randomized controlled trials (RCTs).

METHODS

PubMed, Scopus, and ClinicalTrials.gov were inquired from inception through August 31st, 2022, for RCTs documenting any psychopharmacological intervention for EDs diagnosed according to validated criteria and reporting weight and psychopathology changes. Adopted keywords were: "anorexia nervosa," "bulimia nervosa," "binge eating disorder," "antidepressant," "antipsychotic," and "mood stabilizer." No language restriction applied.

RESULTS

5122 records were identified, and 203 full-texts were reviewed. Sixty-two studies entered the qualitative synthesis (AN = 22, BN = 23, BED = 17), of which 22 entered the meta-analysis (AN = 9, BN = 10, BED = 3). Concerning BMI increase in AN, olanzapine outperformed placebo (Hedges'g = 0.283, 95%C·I. = 0.051-0.515, I2 = 0 %; p = .017), whereas fluoxetine failed (Hedges'g = 0.351, 95%C.I. = -0.248 to 0.95, I2 = 63.37 %; p = .251). Fluoxetine not significantly changed weight (Hedges'g = 0.147, 95%C.I. = -0.157-0.451, I2 = 0 %; p = .343), reducing binging (Hedges'g = 0.203, 95%C.I. = 0.007-0.399, I2 = 0 %; p = .042), and purging episodes (Hedges'g = 0.328, 95%C.I. = -0.061-0.717, I2 = 58.97 %; p = .099) in BN. Lisdexamfetamine reduced weight (Hedges'g = 0.259, 95%C.I. = 0.071-0.446, I2 = 0 %; p = .007) and binging (Hedges'g = 0.571, 95%C.I. = 0.282-0.860, I2 = 53.84 %; p < .001) in BED.

LIMITATIONS

Small sample size, short duration, and lack of reliable operational definitions affect most of the included sponsored RCTs.

CONCLUSIONS

The efficacy of different drugs varies across different EDs, warranting additional primary studies recording broad psychopathological and cardiometabolic outcomes besides weight, especially against established psychotherapy interventions.

World Federation of Societies of Biological Psychiatry (WFSBP) guidelines update 2023 on the pharmacological treatment of eating disorders

OBJECTIVES

This 2023 update of the WFSBP guidelines for the pharmacological treatment of eating disorders (EDs) reflects the latest diagnostic and psychopharmacological progress and the improved WFSBP recommendations for the assessment of the level of evidence (LoE) and the grade of recommendation (GoR).

METHODS

The WFSBP Task Force EDs reviewed the relevant literature and provided a timely grading of the LoE and the GoR.

RESULTS

In anorexia nervosa (AN), only a limited recommendation (LoE: A; GoR: 2) for olanzapine can be given, because the available evidence is restricted to weight gain, and its effect on psychopathology is less clear. In bulimia nervosa (BN), the current literature prompts a recommendation for fluoxetine (LoE: A; GoR: 1) or topiramate (LoE: A; GoR: 1). In binge-eating disorder (BED), lisdexamfetamine (LDX; LoE: A; GoR: 1) or topiramate (LoE: A; GoR: 1) can be recommended. There is only sparse evidence for the drug treatment of avoidant restrictive food intake disorder (ARFID), pica, and rumination disorder (RD).

CONCLUSION

In BN, fluoxetine, and topiramate, and in BED, LDX and topiramate can be recommended. Despite the published evidence, olanzapine and topiramate have not received marketing authorisation for use in EDs from any medicine regulatory agency.

Efficacy and tolerance of second-generation antipsychotics in anorexia nervosa: A systematic scoping review

INTRODUCTION

Second-generation antipsychotics (SGAs) are frequently prescribed for the treatment of resistant anorexia nervosa. However, few clinical trials have been conducted so far and no pharmacological treatment has yet been approved by the Food and Drug Administration. The aim of this paper is to conduct a systematic scoping review exploring the effectiveness and safety of atypical antipsychotics in anorexia nervosa (AN).

METHOD

We conducted a systematic scoping review of the effectiveness and tolerability of SGAs in the management of AN. We included articles published from January 1, 2000, through September 12, 2022 from the PubMed and PsycInfo databases and a complementary manual search. We selected articles about adolescents and adults treated for AN by four SGAs (risperidone, quetiapine, aripiprazole or olanzapine). This work complies with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis extension for scoping reviews (PRIMA-ScR) and was registered in the Open Science Framework (OSF) repository.

RESULTS

This review included 55 articles: 48 assessing the effectiveness of SGAs in AN and 7 focusing only on their tolerability and safety. Olanzapine is the treatment most frequently prescribed and studied with 7 randomized double-blind controlled trials. Other atypical antipsychotics have been evaluated much less often, such as aripiprazole (no randomized trials), quetiapine (two randomized controlled trials), and risperidone (one randomized controlled trial). These treatments are well tolerated with mild and transient adverse effects in this population at particular somatic risk.

DISCUSSION

Limitations prevent the studies both from reaching conclusive, reliable, robust, and reproducible results and from concluding whether or not SGAs are effective in anorexia nervosa. Nonetheless, they continue to be regularly prescribed in clinical practice. International guidelines suggest that olanzapine and aripiprazole can be interesting in severe or first-line resistant clinical situations.

Gastrointestinal peptides in eating-related disorders

Food intake is tightly controlled by homeostatic signals sensitive to metabolic need for the regulation of body weight. This review focuses on the peripherally-secreted gastrointestinal peptides (i.e., ghrelin, cholecystokinin, glucagon-like peptide 1, and peptide tyrosine tyrosine) that contribute to the control of appetite and discusses how these peptides or the signals arising from their release are disrupted in eating-related disorders across the weight spectrum, namely anorexia nervosa, bulimia nervosa, and obesity, and whether they are normalized following weight restoration or weight loss treatment. Further, the role of gut peptides in the pathogenesis and treatment response in human weight conditions as identified by rodent models are discussed. Lastly, we review the incretin- and hormone-based pharmacotherapies available for the treatment of obesity and eating-related disorders.

Lower leptin level at discharge in acute anorexia nervosa is associated with early weight-loss

OBJECTIVE

Predictive values of acute phase metabolic abnormalities of anorexia nervosa (AN) have seldom been studied. As early postrestoration weight loss is associated with poor outcome, discharge biologic parameters were assessed to detect an association with 2-month follow-up weight loss as a proxy to poor outcome.

METHOD

Fasting plasma levels of leptin, acyl-ghrelin, obestatin, PYY, oxytocin and BDNF were measured in 26 inpatients, at inclusion, at discharge and 2 months later. A body mass index less than 18 2-month postdischarge was considered a poor outcome.

RESULTS

Nineteen patients (73%) had a fair outcome and seven (27%) had a poor one with a mean loss of 0.69 versus 4.54 kg, respectively. Only discharge leptin levels were significantly higher in fair versus poor outcome patients (14.1 vs. 7.0 ng/ml, p = 0.006). The logistic regression model using discharge leptin, acyl-ghrelin, obestatin, oxytocin, PYY and BDNF levels as predictors of outcome disclosed a nearly significant effect of leptin (p < 0.10). Receiver operating characteristic analysis showed 11.9 ng/ml was the best value of threshold. Neither clinical variables differed according to outcome.

CONCLUSION

Leptin level may be a biomarker of early weight relapse after acute inpatient treatment of AN. Its clinical usefulness in monitoring care in AN should further be determined.

A Systematic Review and Meta-Analysis Finds Increased Blood Levels of All Forms of Ghrelin in Both Restricting and Binge-Eating/Purging Subtypes of Anorexia Nervosa

Anorexia nervosa (AN) is a severe psychiatric condition associated with high mortality and chronicity. The hunt for state, trait, subtyping, and prognostic biomarkers is ongoing and the orexigenic hormone ghrelin and its different forms, acyl ghrelin and desacyl ghrelin, have been proposed to be increased in AN, especially in the restrictive subtype. A systematic literature search was performed using established databases up to 30 November 2020. Forty-nine studies met inclusion criteria for cross-sectional and longitudinal meta-analyses on total ghrelin, acyl ghrelin, and desacyl ghrelin. All forms of ghrelin were increased in the acute stage of anorexia nervosa during fasting compared to healthy controls. Previous notions on differences in ghrelin levels between AN subtypes were not supported by current data. In addition, a significant decrease in total ghrelin was observed pre-treatment to follow-up. However, total ghrelin levels at follow-up were still marginally elevated compared to healthy controls, whereas for acyl ghrelin, no overall effect of treatment was observed. Due to heterogeneity in follow-up designs and only few data on long-term recovered patients, longitudinal results should be interpreted with caution. While the first steps towards a biomarker in acute AN have been completed, the value of ghrelin as a potential indicator of treatment success or recovery status or its use in subtype differentiation are yet to be established.

Pharmacological treatment of acute-phase anorexia nervosa: Evidence from randomized controlled trials

BACKGROUND

Anorexia nervosa (AN) is the psychiatric disorder with the highest mortality rate, with a standard mortality ratio of 5.86. Despite the large use of psychotropic drugs in the clinical setting, Food and Drug Administration has not approved any psychoactive treatment for AN.

AIMS

The aim of this study was to perform an updated systematic review and meta-analysis of published randomized controlled trials (RCTs) investigating psychopharmacological treatment in acute-phase AN.

METHODS

The present paper follows the preferred reporting items for systematic reviews and meta-analyses (PRISMA) statement. An extensive literature search was performed. All RCTs enrolling patients with acute-phase AN, comparing at least one psychotropic drug with another drug, placebo, treatment-as-usual or no treatment were included. The main outcome was the effect of psychoactive drugs on body mass index (BMI); data on psychopathological outcomes were also collected when available.

RESULTS

A total of 19 RCTs met all specified criteria. Of these, 11 were excluded from quantitative analyses. Of the eight studies included in the meta-analyses, five reported data on BMI, showing no significant difference between olanzapine and placebo for weight recovery. No significant result was found for AN psychopathology, depressive and anxious symptoms for any of the molecules studied.

CONCLUSIONS

RCTs published in this field display methodological biases, low sample sizes and short follow-up periods. Further research efforts are needed in this field as no evidence has been demonstrated for the use of any psychotropic drug in acute-phase AN neither for weight recovery, nor for comorbid psychiatric symptoms.

Olanzapine in the treatment of anorexia nervosa: a systematic review

Anorexia nervosa, with the highest mortality rate among psychiatric diseases, is characterized by low body mass index, fear of weight gain, and disturbed body image. Even though multiple drugs have been proposed for the treatment of anorexia nervosa, current treatment modalities include nutritional support and psychotherapy. In this study, our aim is to analyze the efficiency and possible adverse effects of olanzapine, an atypical anti-psychotic drug, in the treatment of anorexia nervosa. The studies investigating the efficiency and possible adverse effects of olanzapine in anorexia nervosa have been searched by using 3 databases (Embase, PubMed, and Cochrane Library). DerSimonian-Laird random effects meta-analyses have been used in the statistical analysis. Effect of olanzapine treatment in accordance with the duration and dosage of drug have been analyzed by the determination of 95% confidence intervals (p value < 0.05 is considered as statistically significant). Despite the presence of some contradictory studies, olanzapine treatment has been found beneficial in anorexia nervosa. In addition, analysis reveals that statistically significant beneficial effect of olanzapine treatment is used at high doses and for short duration. Possible side effects include neuroleptic malignant syndrome, hypoglycemia, and heart block in patients suffering from anorexia nervosa. Even though there is obvious need for more comprehensive further studies, current literature favors olanzapine treatment. The efficiency of olanzapine is considered to be related to changes in dopaminergic and serotonergic system in anorexic patients both in terms of neurotransmitter levels and receptor activity.

Pharmacotherapeutic strategies for the treatment of anorexia nervosa - too much for one drug?

INTRODUCTION

Anorexia nervosa is a severe psychiatric illness and no medication has been approved for its treatment. This lack of biological treatments requires the development of new directions for pharmacological research.

AREAS COVERED

There is modest but emerging evidence that dopamine D2 and serotonin 1A and 2A receptor agonistic and antagonist medication might be beneficial for weight gain, although the underlying mechanisms are uncertain. Improving quality of life including treating comorbid conditions is an additional important outcome measure, but this has not been well researched. Biological and psychological risk factors together with neurobiological alterations during the illness maintain the disorder 's pathophysiology. Neuroscience research can be used to understand those interactions and advance the research agenda. The authors discuss the above as well as give perspectives on future research.

EXPERT OPINION

If a multidisciplinary approach that includes evidence-based psychotherapy shows unsatisfactory success in weight normalization and cognitive-emotional recovery, then more experimental treatments that are safe and have indicated treatment effectiveness should be tried to augment treatment. Identification and treatment of comorbid conditions to improve quality of life of the patient should also be part of the treatment regimen, even if the effect on weight gain is uncertain.

A Meta-Analysis of Dropout and Metabolic Effects of Antipsychotics in Anorexia Nervosa

BACKGROUND

Second-generation antipsychotics are often used off-label in the treatment of anorexia nervosa (AN) across the clinical spectrum. Patients with anorexia nervosa often cite concerns about metabolic effects, such as weight gain, as reasons for their reluctance to start or continue second-generation antipsychotics. Improving our understanding of the metabolic effect patients experience and reasons underlying their disinclination will enable us to build rapport and guide our clinical decisions. We therefore aimed to conduct a comprehensive review of dropouts, metabolic effects, and patient-reported outcomes associated with second-generation antipsychotic in people with AN.

METHOD

EMBASE, Medline, and PsycINFO were searched for all relevant studies published until 2019, and retrieved studies were assessed for eligibility as per predefined inclusion criteria. A random-effects meta-analysis was conducted to assess overall dropout rates.

RESULTS

Of 983 citations retrieved, 21 studies met the inclusion criteria for the systematic review and 10 studies had appropriate data for meta-analysis. Using the random effects model, the pooled dropout rate in the intervention arm (95% confidence interval) from psychopharmacological trials was 28% (19 to 38%) in people with AN. Personal reasons or factors associated with study were commonest reason for dropout, not adverse events or metabolic effects as hypothesized.

CONCLUSION

Compared to personal reasons, drug-related factors such as side effects seem to play a lesser role for the discontinuation of antipsychotic treatment under trial conditions. This suggests an urgent need to consider and fully examine potential individual and patient-related factors that influence dropout rates in psychopharmacological trials and treatment compliance in clinical settings.

Medication in AN: A Multidisciplinary Overview of Meta-Analyses and Systematic Reviews

Drugs are widely prescribed for anorexia nervosa in the nutritional, somatic, and psychiatric fields. There is no systematic overview in the literature, which simultaneously covers all these types of medication. The main aims of this paper are (1) to offer clinicians an overview of the evidence-based data in the literature concerning the medication (psychotropic drugs and medication for somatic and nutritional complications) in the field of anorexia nervosa since the 1960s, (2) to draw practical conclusions for everyday practise and future research. Searches were performed on three online databases, namely MEDLINE, Epistemonikos and Web of Science. Papers published between September 2011 and January 2019 were considered. Evidence-based data were identified from meta-analyses, if there were none, from systematic reviews, and otherwise from trials (randomized or if not open-label studies). Evidence-based results are scarce. No psychotropic medication has proved efficacious in terms of weight gain, and there is only weak data suggesting it can alleviate certain psychiatric symptoms. Concerning nutritional and somatic conditions, while there is no specific, approved medication, it seems essential not to neglect the interest of innovative therapeutic strategies to treat multi-organic comorbidities. In the final section we discuss how to use these medications in the overall approach to the treatment of anorexia nervosa.

The Role of Ghrelin in Anorexia Nervosa

Ghrelin, a 28-amino acid peptide hormone expressed in X/A-like endocrine cells of the stomach, is the only known peripherally produced and centrally acting peptide that stimulates food intake and therefore attracted a lot of attention with one major focus on the treatment of conditions where an increased energy intake or body weight gain is desired. Anorexia nervosa is an eating disorder characterized by a pronounced reduction of body weight, a disturbed body image and hormonal alterations. Ghrelin signaling has been thoroughly investigated under conditions of anorexia nervosa. The present review will highlight these alterations of ghrelin in anorexia and discuss possible treatment strategies targeting ghrelin signaling. Lastly, gaps in knowledge will be mentioned to foster future research.

Association between antipsychotic treatment and leptin levels across multiple psychiatric populations: An updated meta-analysis

OBJECTIVE

Antipsychotics (APs) are associated with metabolic syndrome, with increases in leptin proposed as an underlying mechanism of AP-induced weight gain. Currently available meta-analyses on this topic have limited their populations of interest to those diagnosed with schizophrenia. The purpose of this meta-analysis is to explore the relationship between leptin levels and AP use across multiple psychiatric diagnoses, and also in healthy controls.

METHOD

Systematic electronic searches were conducted using PubMed and OVID: Medline. Longitudinal studies were included if showing leptin levels before and after AP use. We included participants with any psychiatric disorders and mentally healthy participants, if exposed to AP use. The differences in leptin levels were evaluated using Hedges' g with a random effects model.

RESULTS

Forty-two studies were found (36 schizophrenia, 2 bipolar disorder, 1 anorexia nervosa, and 3 healthy controls), encompassing 66 study arms and 1,156 participants. The meta-analysis showed that regardless of diagnoses, leptin levels increase with AP use (Hedges' g = 0.811, p ≤ .001).

CONCLUSION

Leptin increases induced by APs are present across all diagnoses. More comprehensive research is needed to understand the relationship between AP use and leptin levels across multiple diagnoses.

The Role of Psychotropic Medications in the Management of Anorexia Nervosa: Rationale, Evidence and Future Prospects

Anorexia nervosa (AN) is a severe psychiatric disorder without approved medication intervention. Every class of psychoactive medication has been tried to improve treatment outcome; however, randomized controlled trials have been ambiguous at best and across studies have not shown robust improvements in weight gain and recovery. Here we review the available literature on pharmacological interventions since AN came to greater public recognition in the 1960s, including a critical review of why those trials may not have been successful. We further provide a neurobiological background for the disorder and discuss how cognition, learning, and emotion-regulating circuits could become treatment targets in the future. Making every effort to develop effective pharmacological treatment options for AN is imperative as it continues to be a complex psychiatric disorder with high disease burden and mortality.

Psychopharmacological options for adult patients with anorexia nervosa

The aim of this review was to summarize evidence from research on psychopharmacological options for adult patients with anorexia nervosa (AN). Database searches of MEDLINE and PsycINFO (from January 1966 to January 2014) were performed, and original articles published as full papers, brief reports, case reports, or case series were included. Forty-one papers were screened in detail, and salient characteristics of pharmacological options for AN were summarized for drug classes. The body of evidence for the efficacy of pharmacotherapy in AN was unsatisfactory, the quality of observations was questionable (eg, the majority were not blinded), and sample size was often small. More trials are needed, while considering that nonresponse and nonremission are typical of patients with AN.

Meta analysis on the efficacy of pharmacotherapy versus placebo on anorexia nervosa

BACKGROUND

Anorexia Nervosa (AN) has a devastating impact on the psychological and physical well being of affected individuals. There is an extensive body of literature on interventions in AN, however more studies are needed to establish which form of pharmacotherapy is effective. The few meta-analyses that have been done are based on one type of medication only. This article is the first to present data on three different, most commonly used, forms of pharmacotherapy. The primary objective of this meta-analysis was to create an overview and to determine the efficacy of three forms of pharmacotherapy (antidepressants, antipsychotics, hormonal therapy) compared to treatment with placebo in patients with AN.

METHOD

A systematic literature search was performed to identify all randomized controlled intervention trials investigating the effectiveness of pharmacotherapy for AN within the following databases: PubMed, PsycINFO, Embase and Cochrane Library. In addition, 32 relevant reviews and meta-analyses were screened for additional intervention studies. A meta-analysis was performed on a total of 18 included studies (N = 869). Efficacy was measured in terms of weight gain or weight restoration.

RESULTS

The pooled effect sizes indicating the difference between antidepressants and placebo, and between antipsychotics and placebo on weight were not significant. Because of the small sample size no meta regression and subgroup analyses could be conducted. The pooled effect size indicating the difference between hormonal therapy and the placebo condition on weight (all weight measures) at post-treatment was 0.42 (95% CI: 0.11 ~ 0.73), which was significant. For hormonal therapy heterogeneity was high (I(2) = 64.70). No evidence for publication bias was found. Meta-regression analyses of the weeks of medication treatment (slope = -0.008) yielded a significant effect (p = 0.04).

CONCLUSIONS

In this study we found that hormonal therapy has a significantly larger effect on weight compared to placebo in the treatment of AN. However for these analyses heterogeneity was high, which means that these results have to be regarded with caution. We found that anti-depressants and antipsychotics had no significant effect on weight compared to placebo in the treatment of AN, although the power to detect significant effects was too low.

Second generation antipsychotic-induced type 2 diabetes: a role for the muscarinic M3 receptor

Second generation antipsychotics (SGAs) are widely prescribed to treat various disorders, most notably schizophrenia and bipolar disorder; however, SGAs can cause abnormal glucose metabolism that can lead to insulin-resistance and type 2 diabetes mellitus side-effects by largely unknown mechanisms. This review explores the potential candidature of the acetylcholine (ACh) muscarinic M3 receptor (M3R) as a prime mechanistic and possible therapeutic target of interest in SGA-induced insulin dysregulation. Studies have identified that SGA binding affinity to the M3R is a predictor of diabetes risk; indeed, olanzapine and clozapine, SGAs with the highest clinical incidence of diabetes side-effects, are potent M3R antagonists. Pancreatic M3Rs regulate the glucose-stimulated cholinergic pathway of insulin secretion; their activation on β-cells stimulates insulin secretion, while M3R blockade decreases insulin secretion. Genetic modification of M3Rs causes robust alterations in insulin levels and glucose tolerance in mice. Olanzapine alters M3R density in discrete nuclei of the hypothalamus and caudal brainstem, regions that regulate glucose homeostasis and insulin secretion through vagal innervation of the pancreas. Furthermore, studies have demonstrated a dynamic sensitivity of hypothalamic and brainstem M3Rs to altered glucometabolic status of the body. Therefore, the M3R is in a prime position to influence glucose homeostasis through direct effects on pancreatic β-cells and by potentially altering signalling in the hypothalamus and brainstem. SGA-induced insulin dysregulation may be partly due to blockade of central and peripheral M3Rs, causing an initial disruption to insulin secretion and glucose homeostasis that can progressively lead to insulin resistance and diabetes during chronic treatment.

The effect of atypical antipsychotic medications in individuals with anorexia nervosa: a systematic review and meta-analysis

OBJECTIVE

Given that atypical antipsychotic medications have been increasingly prescribed for improving weight gain in anorexia nervosa (AN), we conducted a systematic review and meta-analyses to estimate the influence of atypical antipsychotics on BMI, eating disorder, and psychiatric symptoms in individuals with AN.

METHOD

Independent reviewers selected studies and extracted study characteristics, methodologic quality, and outcomes for the intention-to-treat group from randomized clinical trials comparing the effect of atypical antipsychotic use to placebo or an active control treatment on BMI.

RESULTS

Compared with placebo, atypical antipsychotics were associated with a nonsignificant increase in BMI (weighted mean difference, WMD = 0.18, 95% CI: -0.36, 0.72; I(2) = 26%) and a nonsignificant effect on the drive for thinness and body dissatisfaction. Compared with placebo or active control, these medications led to an increase in anxiety and overall eating disorder symptoms. However, there was a significant reduction over placebo or active control on level of depression.

Effects of naltrexone on food intake and body weight gain in olanzapine-treated rats

Blockade of opioidergic neurotransmission contributes to reduction in body weight. However, how such blockade affects body weight gain (BWG) attributed to second generation antipsychotic agents (SGAs) has not yet been established. Here we examined the effects of an opioid receptor antagonist, naltrexone (NTX), on food intake and BWG associated with an SGA, olanzapine (OL). Four groups of Wistar Han IGS rats were treated for 28 days with either OL (2 mg/kg twice daily, intraperitoneal (IP)), a combination of OL (2 mg/kg twice daily, IP) + extended-release NTX (50 mg/kg, one-time, intramuscular (IM)), extended-release NTX (50 mg/kg, one-time, IM) or vehicle and their food intake and body weight were measured daily for the first nine days and every other day thereafter. Food intake and BWG that were increased by OL were decreased by the added NTX while NTX alone had no significant effects on food intake or on BWG. Plasma leptin concentrations were significantly elevated in the three groups receiving pharmacological agents, but did not differ among each other, suggesting that changes in leptin secretion and/or clearance alone would not explain the food intake and the body weight findings. Our results extend prior reports on anorexigenic effects of opioid antagonists by demonstrating that such effects may generalize to food intake increases and BWG arising in the context of OL pharmacotherapy.

Reward circuitry dysfunction in psychiatric and neurodevelopmental disorders and genetic syndromes: animal models and clinical findings

This review summarizes evidence of dysregulated reward circuitry function in a range of neurodevelopmental and psychiatric disorders and genetic syndromes. First, the contribution of identifying a core mechanistic process across disparate disorders to disease classification is discussed, followed by a review of the neurobiology of reward circuitry. We next consider preclinical animal models and clinical evidence of reward-pathway dysfunction in a range of disorders, including psychiatric disorders (i.e., substance-use disorders, affective disorders, eating disorders, and obsessive compulsive disorders), neurodevelopmental disorders (i.e., schizophrenia, attention-deficit/hyperactivity disorder, autism spectrum disorders, Tourette's syndrome, conduct disorder/oppositional defiant disorder), and genetic syndromes (i.e., Fragile X syndrome, Prader-Willi syndrome, Williams syndrome, Angelman syndrome, and Rett syndrome). We also provide brief overviews of effective psychopharmacologic agents that have an effect on the dopamine system in these disorders. This review concludes with methodological considerations for future research designed to more clearly probe reward-circuitry dysfunction, with the ultimate goal of improved intervention strategies.

Alterations to melanocortinergic, GABAergic and cannabinoid neurotransmission associated with olanzapine-induced weight gain

Background/Aim

Second generation antipsychotics (SGAs) are used to treat schizophrenia but can cause serious metabolic side-effects, such as obesity and diabetes. This study examined the effects of low to high doses of olanzapine on appetite/metabolic regulatory signals in the hypothalamus and brainstem to elucidate the mechanisms underlying olanzapine-induced obesity.

Methodology/Results

Levels of pro-opiomelanocortin (POMC), neuropeptide Y (NPY) and glutamic acid decarboxylase (GAD₆₅, enzyme for GABA synthesis) mRNA expression, and cannabinoid CB1 receptor (CB1R) binding density (using [³H]SR-141716A) were examined in the arcuate nucleus (Arc) and dorsal vagal complex (DVC) of female Sprague Dawley rats following 0.25, 0.5, 1.0 or 2.0 mg/kg olanzapine or vehicle (3×/day, 14-days). Consistent with its weight gain liability, olanzapine significantly decreased anorexigenic POMC and increased orexigenic NPY mRNA expression in a dose-sensitive manner in the Arc. GAD₆₅ mRNA expression increased and CB1R binding density decreased in the Arc and DVC. Alterations to neurotransmission signals in the brain significantly correlated with body weight and adiposity. The minimum dosage threshold required to induce weight gain in the rat was 0.5 mg/kg olanzapine.

Conclusions

Olanzapine-induced weight gain is associated with reduced appetite-inhibiting POMC and increased NPY. This study also supports a role for the CB1R and GABA in the mechanisms underlying weight gain side-effects, possibly by altering POMC transmission. Metabolic dysfunction can be modelled in the female rat using low, clinically-comparable olanzapine doses when administered in-line with the half-life of the drug.

Cognitive profile, parental education and BMI in children: reflections on common neuroendrocrinobiological roots

Overweight and obesity may be associated with cognitive problems and both may share "neuroendocrinobiological roots" in common cerebral areas. We investigated intellectual performances and a possible "specific cognitive profile" in overweight/obese children. A cross-sectional study was conducted on 898 school children (6 to 13 years) attending primary schools. Wechsler Intelligence Scale for Children-revised (WISC-R) revealed significant differences in performance intelligence quotient (PIQ) scores between body mass index (BMI) subgroups (p < 0.01). Regression analysis identified BMI as the only variable significantly related to PIQ (p < 0.05). Gender (p < 0.05) and parental educational score (p < 0.001) were significantly related to verbal intelligence quotient (VIQ). Parental educational score was the only factor significantly related to total intelligence quotient (TIQ) (p < 0.05). Parental education seems to play a major role in TIQ and VIQ; a lower PIQ score is clearly related to a higher BMI. A routine neurocognitive assessment in overweight/obese children is recommended. Finally, we have added some reflections on common neuroendocrinobiological roots.

Atypical antipsychotics and anorexia nervosa: a review

BACKGROUND

There is currently mixed opinion regarding the value of using atypical antipsychotics to treat anorexia nervosa (AN).

AIMS

To evaluate the literature on the use of atypical antipsychotics in AN.

METHOD

A review of all studies and clinical guidelines published before September 2009 involving use of an atypical antipsychotic in patients with AN. Analysis is by narrative synthesis.

RESULTS

Forty-three publications or study protocols were found, including four randomized-controlled trials, five open-label trials and 26 case reports. The most studied drugs were olanzapine, quetiapine and risperidone. Atypical antipsychotics appear safe and there is some evidence of positive effects on depression, anxiety and core eating disordered psychopathology in patients with anorexia nervosa. Currently there is insufficient evidence to confirm atypical antipsychotics enhance weight gain in this setting.

CONCLUSIONS

Further high quality evidence is needed in this area in order to provide practical guidance to clinicians. However, the main challenge is to persuade adequate numbers of AN patients to participate in research trials.

Role of the ghrelin/obestatin balance in the regulation of neuroendocrine circuits controlling body composition and energy homeostasis

Ghrelin and obestatin are two peptides isolated from the gastrointestinal tract and encoded by the same preproghrelin gene. They convey to the central nervous system informations concerning the nutritional status and/or the energy stores. Ghrelin, mostly acting through the GH secretagogue receptor GHS-R, is a potent GH secretagogue, an orexigenic peptide and a long-term regulator of energy homeostasis. Obestatin was initially described for its anorexigenic effects and its binding to the G protein-coupled receptor 39 (GPR39). However, the role of obestatin is still controversial and the nature of the obestatin receptor remains an open question. This review is focussed on the possible implication of the ghrelin/obestatin system in psychiatric diseases with particular emphasis on eating disorders.

Leptin, ghrelin, and endocannabinoids: potential therapeutic targets in anorexia nervosa

Anorexia nervosa (AN) has the highest mortality rate between psychiatric disorders, and evidence for managing it is still very limited. So far, pharmacological treatment has focused on a narrow range of drugs and only a few controlled studies have been performed. Furthermore, the studies have been of short duration and included a limited number of subjects, often heterogenic with regard to stage and acute nutritive status. Thus, novel approaches are urgently needed. Body weight homeostasis is tightly regulated throughout life. With the discovery of orexigenic and anorectic signals, an array of new molecular targets to control eating behavior has emerged. This review focuses on recent advances in three important signal systems: leptin, ghrelin, and endocannabinoids toward the identification of potential therapeutical breakthroughs in AN. Our review of the current literature shows that leptin may have therapeutic potentials in promoting restoration of menstrual cycles in weight restored patients, reducing motor restlessness in severely hyperactive patients, and preventing osteoporosis in chronic patients. Ghrelin and endocannabinoids exert orexigenic effects which may facilitate nutritional restoration. Leptin and endocannabinoids may exert antidepressive and anxiolytic effects. Finally, monitoring serum concentration of leptin may be useful in order to prevent refeeding syndrome.

What potential role is there for medication treatment in anorexia nervosa?

OBJECTIVE

To review selected issues regarding the development of drug treatments for anorexia nervosa (AN).

METHOD

The existing pharmacotherapy literature for AN is reviewed, and the theoretical and practical considerations are discussed.

RESULTS

A very wide variety of drugs have been examined in AN, generally with negative results. There are a number of potential reasons for this finding, including compliance, nutritional deficits, selection of the wrong targets or the wrong outcome measures, use of monotherapy, lack of animal models, or factors intrinsic to AN.

CONCLUSION

Pharmacotherapy provides little benefit in the treatment of AN at present. Several strategies might lead to the identification of more effective agents, including new measurement strategies, identification of novel pharmacologic targets, and consideration of a clinical trials network.

Heat reversal of activity-based anorexia: implications for the treatment of anorexia nervosa

OBJECTIVE

Activity-based anorexia (ABA) provides an animal model of anorexia nervosa (AN). In this model, rats given restricted access to food but unrestricted access to activity wheels, run excessively while reducing food intake, lose a sizeable percentage of body weight, become hypothermic, and can fail to recover unless removed from these conditions.

METHOD

Once rats had lost 20% of body weight under standard ABA conditions, they were assigned to one of two ambient temperature (AT) conditions.

RESULTS

Increased AT reduced running rates and led to weight gain in active rats. The effect of increasing AT on food intake was dependent on whether the rats were sedentary or active. Although warming reduced food intake in the sedentary rats their body weight remained stable, whereas in active rats increased AT did not reduce food intake and weight gain gradually rose.

CONCLUSION

From a translational perspective, these findings offer a fresh perspective to the disorder, and underscore the need for further studies to assess the effects of heat treatment in patients as an innovative adjunctive treatment for anorexia nervosa.

Atypical antipsychotics in severe anorexia nervosa in children and adolescents--review and case reports

OBJECTIVE

To review the literature on the use of atypical antipsychotics in anorexia nervosa of children and adolescents and to present three case reports on quetiapine treatment of this subgroup.

METHOD

Review of the literature and case report.

RESULTS

Several case reports and two small open-label trials, mainly in adults, observed beneficial effects of olanzapine on anorexic psychopathology. Only 16 case reports have been published on children and adolescents. Because of its lower propensity to induce weight gain quetiapine might be favourable with regard to patients' compliance. Our case reports revealed positive psychopathological effects and good tolerability of quetiapine in minors with severe anorexia nervosa. Careful titration and intense drug monitoring are recommended.

DISCUSSION

In a small subset of patients with severe, treatment- resistant anorexia nervosa, extreme weight phobia, delusional body image disturbances or severe hyperactivity might be considered as indications for atypical antipsychotics. However, controlled studies are needed.