Plasma prolactin response to D-fenfluramine is blunted in bulimic patients with frequent binge episodes

Brain serotonin deficiency and fluoxetine lead to sex-specific effects on binge-like food consumption in mice

RATIONALE

Although pharmacotherapies are often effective in reducing binge eating in conditions such as bulimia nervosa and binge eating disorder, subsets of patients do not benefit sufficiently from existing treatments, and the reasons for treatment failure remain unclear.

OBJECTIVES

This study aimed to evaluate whether genetic reductions in brain serotonin influence binge eating and/or the ability of fluoxetine, a selective serotonin reuptake inhibitor, to reduce binge eating in mice.

METHODS

This study used a validated model of binge-like consumption of high-fat diet to compare binge-like food intake in control and fluoxetine-treated wild-type and serotonin-deficient mice from the tryptophan hydroxylase 2 (R439H) knock-in line. In addition, real-time PCR was used to evaluate potential genotype and sex differences in the effects of fluoxetine on gene expression in the raphe nucleus.

RESULTS

The results reveal that brain serotonin deficiency is sufficient to increase binge eating in males, but not females. However, while chronic fluoxetine reduced binge eating in both genotypes of males and in wild-type females, it failed to reduce binge eating in serotonin-deficient females. Transcriptional responses to chronic fluoxetine were also characterized by sex and genotype differences.

CONCLUSIONS

Overall, this study revealed significant sex differences in the effects of fluoxetine and brain serotonin deficiency on binge-like food intake and suggests that low brain serotonin could impact eating disorders both by promoting binge eating and by limiting the efficacy of fluoxetine to reduce binge eating.

The association between binge eating disorder and weight management in overweight and obese adults: A systematic literature review

Aim: Weight loss is shown to improve obesity-related health problems as long as it is maintained for a long term. The purpose of this systematic review was to investigate the association between binge eating disorder and weight management in overweight and obese adults. Methods: A systematic search following the preferred reporting items for systematic reviews and meta-analyses guidelines was conducted across PubMed, Ebsco and Cochrane Library from inception through December 2020 to identify studies that assessed the association between binge eating disorder and weight management (e.g., weight loss, weight gain and weight loss maintenance) in overweight and obese adults. We included studies that examined adults (≥18 years old) being overweight and obese with and without binge eating behaviour. Two authors independently screened and evaluated studies for methodological quality. Results: Nine articles were selected, including 3685 participants. Three of the included studies were randomised control trials and the remaining were observational studies. The majority of the studies included support that people who have binge eating disorder may have an additional barrier maintaining their weight loss compared to people who do not suffer from binge eating disorder. Conclusion: Our systematic review revealed that binge eating disorder may have a negative association with weight loss maintenance. Further well-conducted prospective cohort studies and randomised clinical trials are required to investigate the possible mechanisms and whether any such mechanisms are modifiable. These will lead us to more efficient strategies targeting weight management.

A systematic review of blood-based serotonergic biomarkers in Bulimia Nervosa

Bulimia Nervosa (BN) is a serious eating disorder, which affects 0.8-2.9% of the young population. The etiology is unknown and biomarkers would support in understanding the pathophysiology of BN, and in identifying BN patients that may benefit from medical treatment. This systematic review aims to answer whether (a) BN deviate from healthy controls in terms of serotonin (5-HT) biomarkers in blood, and whether (b) blood-based 5-HT biomarkers could be used to tailor psychopharmacological treatment in BN. A literature search using PubMed, PsycINFO and Embase was done using the following search terms: "Bulimia Nervosa" AND "serotonin" AND "blood" OR "plasma" OR "serum". 32 studies were included in this systematic review. Several biomarkers and challenge tests were identified and all studies described an association with BN and dysregulation of the 5-HT system compared to healthy controls. Several studies pointed to an association also to borderline symptoms in BN. BN deviate from healthy controls in terms of 5-HT biomarkers in blood supporting an abnormal 5-HT system in BN. 5-HT biomarkers and associated methods could be used to tailor treatment in BN although as yet, most tests described are unpractical for bedside use.

Role of impulsivity and reward in the anti-obesity actions of 5-HT2C receptor agonists

The selective 5-HT_2C receptor agonist lorcaserin entered clinical obesity trials with the prevalent view that satiety was a primary mechanism of action. Subsequent Phase II and III trials demonstrated efficacy in terms of weight loss, although the overall effect size (~3% placebo-corrected change) is considered modest. Lorcaserin has been approved by the FDA for the treatment of obesity with lifestyle modification, but since its introduction in 2013 its sales are in decline, probably due to its overall modest effect. However, in some individuals, lorcaserin has a much more clinically significant effect (i.e. >10% placebo-corrected change), although what common features, if any, define these high responders is presently unknown. In the present article we highlight the evidence that alternative mechanisms to satiety may contribute to the anti-obesity effect of lorcaserin, namely effects on constructs of primary and conditioned reward and impulsivity. This may better inform the clinical evaluation of lorcaserin (and any future 5-HT_2C receptor agonists) to subgroups of obese subjects characterized by overeating due to maladaptive impulsivity and reward mechanisms. One such population might be individuals diagnosed with binge eating disorder.

Impact of novel palmitoylated prolactin-releasing peptide analogs on metabolic changes in mice with diet-induced obesity

Analogs of anorexigenic neuropeptides, such as prolactin-releasing peptide (PrRP), have a potential as new anti-obesity drugs. In our previous study, palmitic acid attached to the N-terminus of PrRP enabled its central anorexigenic effects after peripheral administration. In this study, two linkers, γ-glutamic acid at Lys¹¹ and a short, modified polyethylene glycol at the N-terminal Ser and/or Lys¹¹, were applied for the palmitoylation of PrRP31 to improve its bioavailability. These analogs had a high affinity and activation ability to the PrRP receptor GPR10 and the neuropeptide FF2 receptor, as well as short-term anorexigenic effect similar to PrRP palmitoylated at the N-terminus. Two-week treatment with analogs that were palmitoylated through linkers to Lys¹¹ (analogs 1 and 2), but not with analog modified both at the N-terminus and Lys¹¹ (analog 3) decreased body and liver weights, insulin, leptin, triglyceride, cholesterol and free fatty acid plasma levels in a mouse model of diet-induced obesity. Moreover, the expression of uncoupling protein-1 was increased in brown fat suggesting an increase in energy expenditure. In addition, treatment with analogs 1 and 2 but not analog 3 significantly decreased urinary concentrations of 1-methylnicotinamide and its oxidation products N-methyl-2-pyridone-5-carboxamide and N-methyl-4-pyridone-3-carboxamide, as shown by NMR-based metabolomics. This observation confirmed the previously reported increase in nicotinamide derivatives in obesity and type 2 diabetes mellitus and the effectiveness of analogs 1 and 2 in the treatment of these disorders.

Obsessive-compulsive (anankastic) personality disorder: toward the ICD-11 classification

Obsessive-compulsive personality disorder (OCPD) is an early-onset disorder characterized by perfectionism, need for control, and cognitive rigidity. Its nosological status is currently under review. Historically, OCPD has been conceptualized as bearing a close relationship with obsessive-compulsive disorder (OCD). In this article, we discuss the diagnosis of OCPD in anticipation of its review for the ICD-11, from the perspective of clinical utility, global applicability, and research planning. Considering the recent establishment of an obsessive-compulsive and related disorders (OCRD) category in DSM-5, we focus on the relationship between OCPD and the disorders that are currently thought to bear a close relationship with OCD, including DSM-5 OCRD, and other compulsive disorders such as eating disorder and autistic spectrum disorder (that were not included in the DSM-5 OCRD category), as well as with the personality disorders, focusing on nosological determinants such as phenomenology, course of illness, heritability, environmental risk factors, comorbidity, neurocognitive endophenotypes, and treatment response. Based on this analysis, we attempt to draw conclusions as to its optimal placement in diagnostic systems and draw attention to key research questions that could be explored in field trials.

Revisiting the serotonin-aggression relation in humans: a meta-analysis

The inverse relation between serotonin and human aggression is often portrayed as "reliable," "strong," and "well established" despite decades of conflicting reports and widely recognized methodological limitations. In this systematic review and meta-analysis, we evaluate the evidence for and against the serotonin deficiency hypothesis of human aggression across 4 methods of assessing serotonin: (a) cerebrospinal fluid levels of 5-hydroxyindoleacetic acid (CSF 5-HIAA), (b) acute tryptophan depletion, (c) pharmacological challenge, and (d) endocrine challenge. Results across 175 independent samples and over 6,500 total participants were heterogeneous, but, in aggregate, revealed a small, inverse correlation between serotonin functioning and aggression, anger, and hostility (r = -.12). Pharmacological challenge studies had the largest mean weighted effect size (r = -.21), and CSF 5-HIAA studies had the smallest (r = -.06). Potential methodological and demographic moderators largely failed to account for variability in study outcomes. Notable exceptions included year of publication (effect sizes tended to diminish with time) and self- versus other-reported aggression (other-reported aggression was positively correlated to serotonin functioning). We discuss 4 possible explanations for the pattern of findings: unreliable measures, ambient correlational noise, an unidentified higher order interaction, and a selective serotonergic effect. Finally, we provide 4 recommendations for bringing much needed clarity to this important area of research: acknowledge contradictory findings and avoid selective reporting practices; focus on improving the reliability and validity of serotonin and aggression measures; test for interactions involving personality and/or environmental moderators; and revise the serotonin deficiency hypothesis to account for serotonin's functional complexity.

From disordered eating to addiction: the "food drug" in bulimia nervosa

The high prevalence of substance abuse in individuals with bulimia nervosa (BN) and the pervasive symptom substitution in many types of drug addiction suggest that a number of substances--including food--can impair an individual's self-control, even in the presence of negative consequences. Nonetheless, the neurobiological similarities between BN and drug addiction are not clearly established. This review explores how the specific eating patterns seen in BN (binge eating and purging, with intermittent dietary restriction) are particularly addictive and differentiate BN from other eating disorders and obesity. A number of peripheral and central biological aberrations seen in BN may result in altered reward sensitivity in these individuals, particularly through effects on the dopaminergic system. Neurobiological findings support the notion that BN is an addictive disorder, which has treatment implications for therapy and pharmacological manipulations.

Should an obsessive-compulsive spectrum grouping of disorders be included in DSM-V?

The obsessive-compulsive (OC) spectrum has been discussed in the literature for two decades. Proponents of this concept propose that certain disorders characterized by repetitive thoughts and/or behaviors are related to obsessive-compulsive disorder (OCD), and suggest that such disorders be grouped together in the same category (i.e. grouping, or "chapter") in DSM. This article addresses this topic and presents options and preliminary recommendations to be considered for DSM-V. The article builds upon and extends prior reviews of this topic that were prepared for and discussed at a DSM-V Research Planning Conference on Obsessive-Compulsive Spectrum Disorders held in 2006. Our preliminary recommendation is that an OC-spectrum grouping of disorders be included in DSM-V. Furthermore, we preliminarily recommend that consideration be given to including this group of disorders within a larger supraordinate category of "Anxiety and Obsessive-Compulsive Spectrum Disorders." These preliminary recommendations must be evaluated in light of recommendations for, and constraints upon, the overall structure of DSM-V.

The possible influence of impulsivity and dietary restraint on associations between serotonin genes and binge eating

Although serotonin (5-HT) genes are thought to be involved in the etiology of bulimia nervosa and binge eating, findings from molecular genetic studies are inconclusive. This may be due to limitations of past research, such as a failure to consider the influence of quantitative traits and gene-environment interactions. The current study investigated these issues by examining whether quantitative traits (i.e., impulsivity) and environmental exposure factors (i.e., dietary restraint) moderate 5-HT gene/binge eating associations in a sample of young women (N = 344). Binge eating was assessed using the Minnesota Eating Behavior Survey and the Dutch Eating Behavior Questionnaire (DEBQ). Impulsivity was assessed with the Barratt Impulsiveness Scale-Version 11. Dietary restraint was measured with a factor score derived from common restraint scales. Saliva samples were genotyped for the 5-HT2a receptor T102C polymorphism and 5-HT transporter promoter polymorphism. As expected, impulsivity and dietary restraint were associated with binge eating. Although the T allele of the 5-HT2a receptor gene and the s allele of the 5-HTT gene were associated with higher levels of impulsivity, there were no main effects of 5-HT genotypes on any binge eating measure, and interactions between genotypes, impulsivity, and dietary restraint were non-significant. In conclusion, we found no evidence to suggest that dietary restraint or impulsivity moderate associations between binge eating and these 5-HT genes. Future research should continue to explore interaction effects by examining larger samples, assessing dietary intake directly, and investigating other genes, traits, and environmental factors that may be related to binge eating and bulimia nervosa.

Does obsessive-compulsive personality disorder belong within the obsessive-compulsive spectrum?

It has been proposed that certain Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition Axis I disorders share overlapping clinical features, genetic contributions, and treatment response and fall within an "obsessive-compulsive" spectrum. Obsessive-compulsive personality disorder (OCPD) resembles obsessive-compulsive disorder (OCD) and other spectrum disorders in terms of phenomenology, comorbidity, neurocognition, and treatment response. This article critically examines the nosological profile of OCPD with special reference to OCD and related disorders. By viewing OCPD as a candidate member of the obsessive-compulsive spectrum, we gain a fresh approach to understanding its neurobiology, etiology, and potential treatments.

Association of a functional serotonin transporter gene polymorphism with binge eating disorder

The pathophysiological mechanisms underlying binge eating disorder (BED) are poorly understood. There is evidence that abnormalities in brain serotonin (5HT) play an important role in binge eating behavior, therefore genes involved in 5HT transmission, such as the 5HT transporter (5HTT) gene, may contribute to the biological vulnerability to BED. We examined whether the polymorphism of the promoter of the 5HTT gene, consisting of a long (L) and a short (S) variant, was associated with BED. Seventy-seven obese or non-obese women with BED, and 61 normal weight control women were genotyped at the 5HTT gene linked polymorphism (5HTTLPR). Statistical analysis showed that both the LL genotype and the L allele of the 5HTTLPR were significantly more frequent in BED subjects. Moreover, the L allele was associated with a moderate but significant risk to develop BED (OR = 2.01, CI = 1.33-3.57). Although these data should be regarded as preliminary because of the small size of our sample, they suggest that the 5HTTPRL may contribute to the genetic susceptibility to BED.

Investigation of the serotonin transporter regulatory region polymorphism in bulimia nervosa: relationships to harm avoidance, nutritional parameters, and psychiatric comorbidity

OBJECTIVE

Genes involved in 5HT transmission have been supposed to contribute to the biologic vulnerability for bulimia nervosa (BN). Because a long (L) and a short (S) variant of the promoter region of the 5HT transporter gene have been identified, we tested whether the 5HTT gene-linked polymorphic region (5HTTLPR) could represent a susceptibility factor for BN and/or could be related to nutritional parameters, harm avoidance personality dimension, and psychiatric comorbidity.

METHODS

A total of 219 white women (125 bulimics and 94 healthy control subjects) underwent a blood sample collection for 5HTTLPR genotyping and a clinical evaluation assessing comorbidity for axis I and II psychiatric disorders, harm avoidance personality dimension, and body composition (only patients).

RESULTS

The distribution of the 5HTTLPR genotypes did not significantly differ between patients and control subjects, although the L allele was significantly more frequent in the former. Bulimic individuals carrying at least one copy of the S allele had significantly lower mean body mass index and body fat mass values and significantly higher mean harm avoidance score than patients with the LL genotype. No significant association was found between the 5HTTLPR genotype and comorbid axis I and II psychiatric disorders.

CONCLUSIONS

These findings support the view that polymorphic variants of the 5HTT promoter region do not play a part in predisposing to BN, whereas they seem to predispose bulimic individuals to nutritional impairment and increased harm avoidance.

Coming to Terms With Risk Factors for Eating Disorders: Application of Risk Terminology and Suggestions for a General Taxonomy

The aims of the present review are to apply a recent risk factor approach (H. C. Kraemer et al., 1997) to putative risk factors for eating disorders, to order these along a timeline, and to deduce general taxonomic questions. Putative risk factors were classified according to risk factor type, outcome (anorexia nervosa, bulimia nervosa, binge-eating disorder, full vs. partial syndromes), and additional factor characteristics (specificity, potency, need for replication). Few of the putative risk factors were reported to precede the onset of the disorder. Many factors were general risk factors; only few differentiated between the 3 eating disorder syndromes. Common risk factors from longitudinal and cross-sectional studies were gender, ethnicity, early childhood eating and gastrointestinal problems, elevated weight and shape concerns, negative self-evaluation, sexual abuse and other adverse experiences, and general psychiatric morbidity. Suggestions are made for the conceptualization of future risk factor studies.

Milnacipran in the treatment of bulimia nervosa: a report of 16 cases

Controlled trials in patients with bulimia nervosa have demonstrated efficacy of antidepressant medications with serotonergic function (e.g. fluoxetine) as well as noradrenergic function (e.g. desipramine). Sixteen out-patients with bulimia nervosa according to DSM-IV criteria were treated in a drug surveillance with 100 mg of milnacipran, a specific serotonin and noradrenaline reuptake inhibitor (SNRI). Ten patients completed the 8-week observation period. The reasons for premature attrition were improvement in one patient (no. 12), a generalized exanthema in one patient (no. 7), severe nausea in one patient (no. 8) and non-compliance due to non-drug-related reasons in three patients (no. 1, 2, and 16). An intent-to-treat analysis exhibited a significant reduction in weekly binge eating and vomiting frequency from baseline to the end of treatment. Three patients stopped binge eating and purging completely during the last week of treatment. Furthermore, there was a concomitant decrease of depression ratings (HAMD, BDI). Our preliminary data give rise to the notion that milnacipran may be promising in the treatment of bulimia nervosa.

Aetiopathogenesis and pathophysiology of bulimia nervosa: biological bases and implications for treatment

Bulimia nervosa is an eating disorder characterised by recurrent episodes of binge eating and associated efforts to purge the ingested calories through self-induced vomiting, laxative or diuretic abuse, fasting or intensive exercise. The aetiopathogenesis and pathophysiology of the disorder are currently unclear. Biological bases have been proposed repeatedly, based on several lines of evidence: hunger, satiety and food choice are regulated by neurotransmitters and neuropeptides, and impairment of eating habits may be related to alterations in the secretion of these chemicals; genetic studies suggest that these neurotransmitter systems are dysfunctional in individuals with bulimia nervosa; and the frequent comorbidity of bulimia nervosa with major depressive and obsessive-compulsive disorders, conditions in which multiple alterations of brain biochemical functions have been demonstrated. Data in the literature suggest that levels of noradrenaline (norepinephrine) and serotonin (5-hydroxytryptamine; 5-HT) are lower in individuals with bulimia nervosa than in healthy controls. Levels of dopamine are similar to, or lower than, those in controls. After remission of the disorder, noradrenergic function returns to that seen in controls, whereas dopaminergic and serotonergic function rebound to levels higher than in controls. Among the neuropeptides, alterations in the levels of neuropeptide Y, peptide YY, beta-endorphin, corticotrophin-releasing hormone, somatostatin, cholecystokinin and vasopressin have been found in the symptomatic phase of bulimia nervosa, with a return to levels seen in controls after remission. Pharmacological treatment of bulimia nervosa that is directed at correction of the neurochemical alterations observed is difficult because of the complexity of the impairments. However, such treatment is necessary and should be continued long after symptomatic remission to ensure reinstitution of cerebral biochemical homeostasis.

Plasma levels of neuroactive steroids are increased in untreated women with anorexia nervosa or bulimia nervosa

OBJECTIVE

Animal data suggest that neuroactive steroids, such as 3alpha,5alpha-tetrahydroprogesterone (3a,5a-THP), dehydroepiandrosterone (DHEA), and its sulfated metabolite (DHEA-S), are involved in the modulation of eating behavior, aggressiveness, mood, and anxiety. Anorexia nervosa (AN) and bulimia nervosa (BN) are eating disorders characterized by abnormal eating patterns, depressive and anxious symptoms, enhanced aggressiveness, and endocrine alterations. Previous studies reported decreased blood levels of DHEA and DHEA-S in small samples of anorexic patients, whereas no study has been performed to evaluate the secretion of these neuroactive steroids in BN as well as the production of 3alpha,5alpha-THP in both AN and BN. Therefore, we measured plasma levels of DHEA, DHEA-S, 3alpha,5alpha-THP and other hormones in patients with AN or BN and explored possible relationships between neuroactive steroids and psychopathology.

METHOD

Ninety-two women participated in the study. There were 30 drug-free AN patients, 32 drug-free BN patients, and 30 age-matched, healthy control subjects. Blood samples were collected in the morning for determination of hormone levels. Eating-related psychopathology, depressive symptoms, and aggressiveness were rated by using specific psychopathological scales.

RESULTS

Compared with healthy women, both AN and BN patients exhibited increased plasma levels of 3alpha,5alpha-THP, DHEA, DHEA-S, and cortisol but reduced concentrations of 17beta-estradiol. Plasma testosterone levels were decreased in anorexic women but not in bulimic women. Plasma levels of neuroactive steroids were not correlated with any clinical or demographic variable.

CONCLUSIONS

These findings demonstrate increased morning plasma levels of peripheral neuroactive steroids in anorexic and bulimic patients. The relevance of such hormonal alterations to the pathophysiology of eating disorders remains to be elucidated.

Aggressive behavioral characteristics and endogenous hormones in women with Bulimia nervosa

Increased aggressiveness frequently occurs in patients with bulimia nervosa (BN), but its neurobiological correlates have been poorly investigated. In this study, we investigated possible relationships between such clinical measure and blood levels of endogenous hormones in patients with BN. Morning plasma levels of testosterone, 17beta-estradiol, prolactin (PRL) and cortisol were measured in 33 bulimic women and 22 healthy female controls. The eating-related psychopathology, depression and aggressiveness were rated by specific psychometric scales. Bulimic patients showed decreased plasma levels of PRL and 17beta-estradiol, and increased concentrations of cortisol and testosterone. Moreover, patients scored higher than healthy controls on rating scales assessing eating-related psychopathology, depressive symptoms and aggressiveness. A significant positive correlation was found between testosterone plasma levels and aggressiveness in patients but not in controls. These findings suggest that in BN, increased plasma levels of testosterone may play a role in the modulation of aggressiveness.

Circulating leptin in patients with anorexia nervosa, bulimia nervosa or binge-eating disorder: relationship to body weight, eating patterns, psychopathology and endocrine changes

A decreased production of leptin has been reported in women with anorexia nervosa (AN) and has been attributed merely to the patients' reduced body fat mass. The extent to which eating patterns, purging behaviors, psychopathology and endocrine changes may contribute to the genesis of leptin alterations has not been deeply investigated. Therefore, we measured plasma levels of leptin, glucose and other hormones in three groups of eating disorder patients with different body weight (BW), eating patterns and purging behaviors. Sixty-seven women, 21 with AN, 32 with bulimia nervosa (BN), 14 with binge-eating disorder (BED) and 25 healthy females volunteered for the study. We found that circulating leptin was significantly reduced in AN and BN patients, but significantly enhanced in women with BED. In anorexics, plasma glucose was decreased, whereas plasma cortisol was enhanced; blood concentrations of 17beta-estradiol and prolactin (PRL) were reduced in both AN, BN and BED patients. In all subject groups, a strong positive correlation emerged between plasma levels of leptin and the subjects' BW or body mass index, but not between leptin and psychopathological measures, plasma glucose, cortisol, PRL and 17beta-estradiol. Since leptin was reduced in both underweight anorexics and normal weight bulimics, but increased in overweight BED women, who compulsively binge without engaging in compensatory behaviors, we suggest that factors other than BW may play a role in the determination of leptin changes in eating disorders.

Decreased platelet monoamine oxidase activity in female bulimia nervosa

The involvement of brain serotonin systems in the pathophysiology of eating disorders has been repeatedly demonstrated in recent studies. Platelet MAO activity is an index of brain serotonin activity and lowered platelet MAO levels have been found in association with impulsive behaviors. In addition, some preliminary reports indicate that platelet MAO could be lowered in eating disorder patients.

METHODS

47 patients with DSM-IV eating disorders were studied, including 30 with bulimia nervosa and 17 with anorexia nervosa binge eating-purging type. Platelet MAO activity was measured by isotopic methods using C-14 benzylamine and compared with a control group of 30 healthy subjects. Impulsive personality features were studied with specific rating scales.

RESULTS

Platelet MAO activity was significantly lower (4.4+/-2.4 nmol/h/10(8) platelets) in the bulimic patients than in the control group (6.9+/-2.5) (p<0.001). No significant differences were found between pure bulimics and binge eating-purging anorectics. Platelet MAO was inversely and significantly correlated with scores on impulsivity scales and with borderline personality disorder characteristics.

CONCLUSIONS

Platelet MAO activity is lowered in patients with bulimia, which may reflect dysfunction in impulse control mechanisms. Since platelet MAO has a predominant genetic component, there is need for studies on the association of low platelet MAO and higher risk for developing eating disorders.