Prolactin response to d-fenfluramine is blunted in people with anorexia nervosa

Acute tryptophan depletion balances altered resting-state functional connectivity of the salience network in female patients recovered from anorexia nervosa

BACKGROUND

It has been suggested that individuals predisposed to or recovered from anorexia nervosa experience a hyperserotonergic state associated with anxiety that might be mitigated by restricted food intake, because diminished levels of the tryptophan precursor lower the central availability of serotonin (5-HT). At the neural level, the salience network is a system of functionally connected brain regions; it has been closely associated with 5-HT functioning and mental disorders (including anorexia nervosa). The aim of the present study was to investigate the effect on the salience network of a temporary dietary manipulation of 5-HT synthesis in patients with anorexia nervosa.

METHODS

In this double-blind crossover study, we obtained data on resting-state functional connectivity from 22 weight-recovered female patients with a history of anorexia nervosa, and 22 age-matched female healthy controls. The study procedure included acute tryptophan depletion (a dietary intervention that lowers the central 5-HT synthesis rate) and a sham condition.

RESULTS

We identified an interaction of group and experimental condition in resting-state functional connectivity between the salience network and the orbitofrontal cortex extending to the frontal pole (F _1,42 = 12.52; p _FWE = 0.026). Further analysis revealed increased resting-state functional connectivity during acute tryptophan depletion in patients recovered from anorexia nervosa, resembling that of healthy controls during the sham condition (T ₄₂ = -0.66; p = 0.51).

LIMITATIONS

The effect of acute tryptophan depletion on the central availability of 5-HT can be judged only indirectly using plasma ratios of tryptophan to large neutral amino acids. Moreover, the definition of anorexia nervosa recovery varies widely across studies, limiting comparability.

CONCLUSION

Taken together, our findings support the notion of 5-HT dysregulation in anorexia nervosa and indicate that reduced 5-HT synthesis and availability during acute tryptophan depletion (and possibly with food restriction) may balance hyperserotonergic functioning and the associated resting-state functional connectivity of the salience network.

Peripheral serotonin transporter DNA methylation is linked to increased salience network connectivity in females with anorexia nervosa

BACKGROUND

Epigenetic variation in the serotonin transporter gene (SLC6A4) has been shown to modulate the functioning of brain circuitry associated with the salience network and may heighten the risk for mental illness. This study is, to our knowledge, the first to test this epigenome–brain–behaviour pathway in patients with anorexia nervosa.

METHODS

We obtained resting-state functional connectivity (rsFC) data and blood samples from 55 acutely underweight female patients with anorexia nervosa and 55 age-matched female healthy controls. We decomposed imaging data using independent component analysis. We used bisulfite pyrosequencing to analyze blood DNA methylation within the promoter region of SLC6A4. We then explored salience network rsFC patterns in the group × methylation interaction.

RESULTS

We identified a positive relationship between SLC6A4 methylation levels and rsFC between the dorsolateral prefrontal cortex and the salience network in patients with anorexia nervosa compared to healthy controls. Increased rsFC in the salience network mediated the link between SLC6A4 methylation and eating disorder symptoms in patients with anorexia nervosa. We confirmed findings of rsFC alterations for CpG-specific methylation at a locus with evidence of methylation correspondence between brain and blood tissue.

LIMITATIONS

This study was cross-sectional in nature, the sample size was modest for the method and methylation levels were measured peripherally, so findings cannot be fully generalized to brain tissue.

CONCLUSION

This study sheds light on the neurobiological process of how epigenetic variation in the SLC6A4 gene may relate to rsFC in the salience network that is linked to psychopathology in anorexia nervosa.

Increased anterior cingulate cortex response precedes behavioural adaptation in anorexia nervosa

Patients with anorexia nervosa (AN) are characterised by increased self-control, cognitive rigidity and impairments in set-shifting, but the underlying neural mechanisms are poorly understood. Here we used functional magnetic resonance imaging (fMRI) to elucidate the neural correlates of behavioural adaptation to changes in reward contingencies in young acutely ill AN patients. Thirty-six adolescent/young adult, non-chronic female AN patients and 36 age-matched healthy females completed a well-established probabilistic reversal learning task during fMRI. We analysed hemodynamic responses in empirically-defined regions of interest during positive feedback and negative feedback not followed/followed by behavioural adaptation and conducted functional connectivity analyses. Although overall task performance was comparable between groups, AN showed increased shifting after receiving negative feedback (lose-shift behaviour) and altered dorsal anterior cingulate cortex (dACC) responses as a function of feedback. Specifically, patients had increased dACC responses (which correlated with perfectionism) and task-related coupling with amygdala preceding behavioural adaption. Given the generally preserved task performance in young AN, elevated dACC responses specifically during behavioural adaption is suggestive of increased monitoring for the need to adjust performance strategies. Higher dACC-amygdala coupling and increased adaptation after negative feedback underlines this interpretation and could be related to intolerance of uncertainty which has been suggested for AN.

Metabolism and Mental Illness

Over the past century, overwhelming evidence has emerged pointing to the hypothalamus of the central nervous system (CNS) as a crucial regulator of systemic control of metabolism, including appetite and feeding behavior. Appetite (or hunger) is a fundamental driver of survival, involving complex behaviors governed by various parts of the brain, including the cerebral cortex. Here, we provide an overview of basic metabolic principles affecting the CNS and discuss their relevance to physiological and pathological conditions of higher brain functions. These novel perspectives may well provide new insights into future research strategies to facilitate the development of novel therapies for treating mental illness.

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.

Lack of efficacy of psychological and pharmacological treatments of disorders of eating behavior: neurobiological background

BACKGROUND

Treatments of eating disorders result too often in partial psychological and physical remission, chronicization, dropout, relapse and death, with no fully known explanations for this failure. In order to clarify this problem, we conducted three studies to identify the biochemical background of cognitive-behavioural psychotherapy (CBT), individual psychology brief psychotherapy (IBPP), and psychotherapy-pharmacotherapy with CBT + olanzapine in anorexics (AN) and bulimics (BN) by measuring the levels of plasma homovanillic acid (HVA) for dopamine secretion, plasma 3-methoxy-4-hydroxy-phenylglycol (MHPG) for noradrenalin secretion, and platelet [3H]-Paroxetin-binding Bmax and Kd for serotonin transporter function. The data were then compared with psychopathological and physical alterations.

METHODS

Study 1 investigated the effects of 4 months of CBT on plasma HVA, MHPG and [3H]-Par-binding in 14 AN-restricted, 14 AN-bingeing/purging, and 22 BN inpatients. Study 2 investigated the effects of 4 months of IBPP on plasma HVA in 15 AN and 17 BN outpatients. Study 3 investigated the effect of 3 months of CBT + olanzapine (5 mg/day) in 30 AN outpatients. The data were analyzed using one-way ANOVA for repeated measures for the changes between basal and post-treatment biological and psychological parameters, two-way ANOVA for repeated measures for the differences in the psychobiological data in the 3 groups, Spearman's test for the correlations between basal and final changes in the psychological and biological scores.

RESULTS

Study 1 revealed significant amelioration of the psychopathology in the AN and BN patients, no effects on HVA, MHPG or Paroxetin binding Kd, and a significant increase in Par-binding Bmax only in the BN patients. Study 2 revealed a significant effect of IBPP on psychopathology in the AN and BN patients, and a significant increase in HVA only in the BN patients. Study 3 revealed a significant positive effect of CBT + olanzapine therapy on the psychopathology and increased HVA values. No correlations were observed in the 3 groups between biological and psychological effects of the three treatments.

CONCLUSIONS

Our data advance suggestions on the mechanism of action of the three therapies; however, the lack of correlations between biochemical and psychological effects casts doubt on their significance. Clinical Trials.gov. Identifier NCT01990755 .

Symptoms of depression and anxiety in anorexia nervosa: links with plasma tryptophan and serotonin metabolism

Depressive, anxiety and obsessive symptoms frequently co-occur with anorexia nervosa (AN). The relationship between these clinical manifestations and the biological changes caused by starvation is not well understood. It has been hypothesised that reduced availability of tryptophan (TRP) could reduce serotonin activity and thus trigger these comorbid symptoms. The aim of this study, during re-feeding in individuals with AN, was to analyse covariations across measures of nutritional status, depressive and anxiety symptoms, and peripheral serotonin markers. Depressive and anxiety symptoms, nutritional status and serotonin markers--whole blood serotonin content, plasma TRP and the ratio between TRP and large neutral amino acids--were assessed for 42 AN participants at admission to inpatient treatment and after re-feeding. Biological measures were compared to those obtained in 42 non-eating disordered subjects. For those with AN, psychological, nutritional and biological parameters improved significantly during hospitalisation. Levels of serotonin markers were significantly lower in the AN group compared to the control group, at admission and at discharge. Increase in the TRP/LNAA ratio was correlated with a decrease in depressive symptoms. In addition, there was a positive correlation between serotonin levels and symptoms of both anxiety and depression at discharge. We speculate that enhanced TRP availability during re-feeding, as a result of the increase in the TRP/LNAA ratio, could restore serotonin neurotransmission and lead to a decrease in depressive symptoms. The association between serotonin and anxiety and depressive symptoms would be consistent with numerous observations indicating abnormal functioning of the serotoninergic system in AN.

[Anorexia nervosa - from a neuroscience perspective]

Anorexia nervosa is a frequent disorder especially among adolescent girls and young women, with high morbidity, mortality, and relapse rates. To date, no single therapeutic approach has proved to be superior to others (Herpertz et al., 2011). It remains unclear how its etiology and pathology are encoded within cognitive, neural, and endocrinological processes that modulate important mechanisms in appetitive processing and weight regulation. Yet, several trait characteristics have been identified in AN which might reflect predisposing factors. Further, altered levels of neuropeptides and hormones that regulate appetite and feeding behavior have been found during both the acute and the recovered state, pointing to dysfunctional mechanisms in AN that persist even after malnutrition has ceased. Researchers are also hoping that brain imaging techniques will allow for a more detailed investigation of the neural basis of reward and punishment sensitivity that appears to be altered in AN. The integration and extension of recent findings in these areas will hopefully provide a more comprehensive understanding of the disorder and hence enable the development of more effective treatments.

Psychobiology of borderline personality traits related to subtypes of eating disorders: a study of platelet MAO activity

Increased and decreased levers of platelet monoamine oxidase (MAO) activity have been reported in patients with eating disorders, indicating abnormalities of the serotonin turnover. However, whether these findings are related to eating disorders or are rather reflecting the pathophysiology of borderline personality traits in these patients is still unknown. Platelet MAO activity and comorbid personality disorders were investigated in 72 patients with different subtypes of eating disorders (ED) and in a group of 28 healthy controls. ED patients comprised the following subtypes: 25 anorexia nervosa (AN) restrictive, 14 AN binge eating-purging (AN b-p), 3 anorexia nervosa not otherwise specified (AN NOS) and 30 bulimia nervosa (BN). Personality disorders and traits were assessed with the Structured Interview for Personality Disorders (SCID-II), the Zanarini Rating Scale for Borderline Personality Disorder, and the Barrat Impulsiveness Scale. Platelet MAO activity was significantly lower in ED patients with comorbid borderline personality disorder (BPD) than in ED without Borderline personality disorder (BDP). Platelet MAO activity was significantly and inversely correlated with the number and severity of BPD clinical features. In the subsample of patients with binge eating-purging symptoms (AN b-p, AN NOS and BN), platelet MAO activity was significantly lower in binge-purge patients with comorbid BPD than in binge-purge patients without BPD. The whole group of eating disorders had a significantly reduced lever of platelet MAO activity compared with the control group. The results suggest that low platelet MAO activity might characterize eating disorders with comorbid borderline personality traits, reflecting greater serotonin dysfunction in these patients. The role of decreased platelet MAO as an endophenotype with specific clinical manifestations should be explored in future studies.

The 5-HTTLPR polymorphism, platelet serotonin transporter activity and platelet serotonin content in underweight and weight-recovered females with anorexia nervosa

Serotonin (5-HT) pathways play an important role in the pathophysiology of anorexia nervosa (AN). In this study, we investigated functional characteristics of the platelet 5-HT transporter and platelet 5-HT content in AN patients at various stages of their illness in comparison to healthy control woman (HCW) controlling for the 5-HTTLPR deletion/insertion polymorphism and other confounding variables. Fasting blood samples of 58 acutely underweight AN patients (acAN, BMI = 15.2 ± 1.4), 26 AN patients of the initial acAN sample after short-term/partial weight restoration (BMI = 17.3 ± 0.9), 36 weight-recovered AN patients (recAN, BMI = 20.7 ± 2.2) and 58 HCW (BMI = 21.6 ± 2.0) were assessed for kinetic characteristics of platelet 5-HT uptake (V (max), K (m)) and platelet 5-HT content. Plasma leptin served as an indicator of malnutrition. Mean V (max) and K (m) values were significantly higher in recAN subjects in comparison to HCW (2.05 ± 0.62 vs. 1.66 ± 0.40 nmol 5-HT/10(9) platelets min and 432 ± 215 vs. 315 ± 136 nmol, respectively) but there were no differences in platelet 5-HT content (464.8 ± 210.6 vs. 472.0 ± 162.2 ng 5-HT/10(9) platelets). 5-HT parameters in acAN patients and HCW were similar. 5-HTTLPR variants were not related to 5-HT platelet variables. In the longitudinal part of the study we found significantly increased 5-HT content but unchanged 5-HT uptake in AN patients after short-term/partial weight restoration. Our results highlight the importance of malnutrition for the interpretation of abnormalities in neurotransmitter systems in AN. Changes in platelet 5-HT transporter activity were related to the stage of the illness but not to 5-HTTLPR genotype. Increased V (max) and K (m) in recovered AN patients might mirror adaptive modulations of the 5-HT system.

Effects of cognitive-behavioral therapy on Eating Disorders: neurotransmitter secretory response to treatment

The effects of cognitive-behavioral therapy (CBT) on central dopamine (DA), noradrenaline (NE) and serotonin (5-HT) secretion were studied in a group of 50 female inpatients, of which 14 suffered from anorexia nervosa restricted type (AN-R), 14 from anorexia nervosa bingeing-purging type (AN-BP), and 22 from bulimia nervosa (BN). The aim of the study was to see whether or not CBT modifies the secretion of central DA (blood homovanillic acid=HVA), NE (blood 3-methoxy-4-hydroxy-phenylglycol=MHPG) and the 5-HT transporter (as evaluated by the platelet paroxetine binding=[(3)H]-Par-binding), if the physical and psychological effects of CBT correlate with changes of the neurotransmitter secretion; and if the biological effects of CBT are linked to specific psychopathological aspect of the disorders. The treatment lasted 20 weeks. Body-mass Index, bingeing and purging, specific AN-BN psychopathological (EDE 12-OD), depression (Beck Inventory), anxiety (STAY Form-Y-1), impulsiveness (Barratt Impulsiveness Scale), self-esteem (Rosenberg Self-Biochemical Scale) and temperament (Temperament and Character Inventory, Cloninger Scale) were assessed at baseline and at the end of the treatment. CBT significantly improved the psychophysical aspects of the diseases. HVA and MHPG concentrations did not change. The [(3)H]-Par-binding parameters, the maximum binding capacity (B(max)) and dissociation constant (K(d)) values did not change in either AN-R or AN-BP patients, while the [(3)H]-Par B(max) (and not the K(d)) increased significantly in BN patients. Correlations emerged between basal and final [(3)H]-Par B(max) values and psychopathological scores, but not between CBT-induced differences between basal and final values. Our data suggest that only in BN CBT may act through changes in 5-HT system function.

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.

Neurobiology of stress-induced reproductive dysfunction in female macaques

It is now well accepted that stress can precipitate mental and physical illness. However, it is becoming clear that given the same stress, some individuals are very vulnerable and will succumb to illness while others are more resilient and cope effectively, rather than becoming ill. This difference between individuals is called stress sensitivity. Stress sensitivity of an individual appears to be influenced by genetically inherited factors, early life (even prenatal) stress, and by the presence or absence of factors that provide protection from stress. In comparison to other stress-related diseases, the concept of sensitivity versus resilience to stress-induced reproductive dysfunction has received relatively little attention. The studies presented herein were undertaken to begin to identify stable characteristics and the neural underpinnings of individuals with sensitivity to stress-induced reproductive dysfunction. Female cynomolgus macaques with normal menstrual cycles either stop ovulating (stress sensitive) or to continue to ovulate (stress resilient) upon exposure to a combined metabolic and psychosocial stress. However, even in the absence of stress, the stress-sensitive animals have lower secretion of the ovarian steroids, estrogen and progesterone, have higher heart rates, have lower serotonin function, have fewer serotonin neurons and lower expression of pivotal serotonin-related genes, have lower expression of 5HT2A and 2C genes in the hypothalamus, have higher gene expression of GAD67 and CRH in the hypothalamus, and have reduced gonadotropin-releasing hormone transport to the anterior pituitary. Altogether, the results suggest that the neurobiology of reproductive circuits in stress-sensitive individuals is compromised. We speculate that with the application of stress, the dysfunction of these neural systems becomes exacerbated and reproductive function ceases.

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.

Neuroendocrine effects of citalopram infusion in anorexia nervosa

Because of the role of serotonin (5HT) in regulating food intake and mood, several studies have focused their attention on the assessment of serotonergic activity in eating disorders, and in particular in anorexia nervosa, but the results have been inconsistent. Citalopram, a highly selective 5HT reuptake inhibitor, has been recently reported as a neuroendocrine probe to assess the serotonergic function in physiological and pathological conditions. We evaluated the adrenocorticotropic hormone (ACTH), cortisol, prolactin (PRL) and growth hormone (GH) secretion during placebo or citalopram IV infusion (20 mg over 120 min), in six women with anorexia nervosa restricter type, and in six healthy women, in order to test the hypothesis that this neurotransmitter system is abnormal in this group of patients. ACTH and PRL secretion was higher during citalopram infusion compared to placebo (p<0.05) in both groups, while cortisol secretion was higher during citalopram infusion only in healthy controls (p<0.05), but not in anorexic patients. GH levels were unaffected by citalopram in both groups. These results demonstrate that serotonergic activation by citalopram affects corticotroph and lactotroph but not somatotroph secretion in anorexic as well as in normal subjects. Our preliminary findings do not support the existence of remarkable alterations in the serotonergic control of anterior pituitary function in anorexia nervosa, while there seems to be an impairment of the adrenal function in this group of patients.

Reduced platelet [3H]paroxetine binding in anorexia nervosa: relationship to eating symptoms and personality pathology

Alterations in serotonin function have been implicated in both anorexia and bulimia nervosa, and previous studies suggest associations between serotonin function and variations in pathological personality traits. Women meeting DSM-IV criteria for anorexia nervosa (AN, 16 with the restricting subtype and 14 with the binge-purge subtype) and 49 healthy control women (CW) provided blood samples for analyses of platelet [(3)H]paroxetine binding. Participants also filled out questionnaires tapping eating disorder symptoms, depression, and personality pathology. Compared with CW, women with restricting and binge-purge AN had significantly lower levels of paroxetine binding (respectively: 1012 + 487 vs. 560 + 253 vs. 618 + 217 fmol/mg protein). Simple correlation analyses showed that, within AN but not within controls, paroxetine binding was inversely related to dieting preoccupations, affective instability, anxiousness, compulsivity, restricted expression and social avoidance but independent of age, body mass index, depression, and other eating symptoms. Findings suggest that reduced peripheral serotonin transporter density in AN relates to increased dieting preoccupations, affective instability and anxiousness-fearfulness.

Serotonin-related gene expression in female monkeys with individual sensitivity to stress

Female cynomolgus monkeys exhibit different degrees of reproductive dysfunction with moderate metabolic and psychosocial stress. In this study, the expression of four genes pivotal to serotonin neural function was assessed in monkeys previously categorized as highly stress resistant (n=3; normal menstrual cyclicity through two stress cycles), medium stress resistant (n=5; ovulatory in the first stress cycle but anovulatory in the second stress cycle), or low stress resistant (i.e. stress-sensitive; n=4; anovulatory as soon as stress is initiated). In situ hybridization and quantitative image analysis was used to measure mRNAs coding for SERT (serotonin transporter), 5HT1A autoreceptor, MAO-A and MAO-B (monoamine oxidases) at six levels of the dorsal raphe nucleus (DRN). Optical density (OD) and positive pixel area were measured with NIH Image software. In addition, serotonin neurons were immunostained and counted at three levels of the DRN. Finally, each animal was genotyped for the serotonin transporter long polymorphic region (5HTTLPR). Stress sensitive animals had lower expression of SERT mRNA in the caudal region of the DRN (P<0.04). SERT mRNA OD in the caudal DRN was positively correlated with serum progesterone during a pre-stress control cycle (P<0.0007). 5HT1A mRNA OD signal tended to decline in the stress-sensitive group, but statistical difference between averages was lacking in analysis of variance. However, 5HT1A mRNA signal was positively correlated with control cycle progesterone (P<0.009). There was significantly less MAO-A mRNA signal in the stress-sensitive group (P<0.007) and MAO-A OD was positively correlated with progesterone from a pre-stress control cycle (P<0.007). MAO-B mRNA exhibited a similar downward trend in the stress-sensitive group. MAO-B OD also correlated with control cycle progesterone (P<0.003). There were significantly fewer serotonin neurons in the stress-sensitive group. All animals contained only the long form of the 5HTTLPR. Thus, all serotonin-related mRNAs examined in the dorsal raphe to date were lower (SERT, MAO-A) or exhibited a lower trend (5HT1A, MAO-B) in the stress sensitive animals, which probably reflects the lower number of serotonin neurons present.

Serotonergic and dopaminergic systems in anorexia nervosa: a role for atypical antipsychotics?

OBJECTIVE

To review serotonergic and dopaminergic system function in anorexia nervosa in terms of potential modulation by atypical antipsychotic medications.

METHOD

A systematic review of clinical, neurobiological and functional neuroimaging findings of serotonergic and dopaminergic system activity in anorexia nervosa was conducted via MEDLINE, PsycINFO and EMBASE psychiatry databases, with a critical review of dysregulation of these systems as therapeutic targets for atypical antipsychotics, in context of evidence regarding the utility and efficacy of these medications in this syndrome.

RESULTS

There is evidence of persistently altered serotonergic and dopaminergic function in anorexia nervosa independent to weight-recovery. Case reports, open-label and single-blinded studies, albeit sparse, suggest that atypical antipsychotics may be beneficial in the management of anorexia nervosa psychopathology beyond weight gain.

CONCLUSIONS

Double-blind placebo controlled studies of atypical antipsychotics in anorexia nervosa with well defined outcome measures are required.

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.

A neurodevelopmental model for anorexia nervosa

This paper integrates genetic and biological data on aetiological risk for anorexia nervosa (AN) with cognitive and psychosocial explanatory models. We have reviewed clinical and basic science data from each of these domains and then used a developmental perspective to formulate a multifactorial threshold model. By positioning interpersonal stress as a central component of this model, psychological, social and biological conceptualisations of AN can be used to generate a data driven, neurodevelopmental hypothesis for the aetiology of this complex disorder.

Anxiolytic effects of acute tryptophan depletion in anorexia nervosa

OBJECTIVE

Recent studies have raised the question as to whether a dysregulation of the neurotransmitter serotonin may contribute to the alterations in mood seen in anorexia nervosa (AN). People with AN tend to be anxious, obsessional, perfectionistic, and harm avoidant. These traits are premorbid and persist after recovery. It has been suggested that increased activity of brain serotonin systems could contribute to this pathologic condition. Dieting in AN, which serves to reduce plasma levels of tryptophan (TRP), may serve to reduce symptoms of dysphoric mood.

METHOD

Fourteen women currently symptomatic with AN (ILL AN), 14 women recovered from AN (REC AN), and 15 healthy control women (CW) underwent acute tryptophan depletion (ATD). Measures of psychological state were self-assessed at baseline and hourly after ATD to determine whether ATD would reduce negative mood.

RESULTS

ILL AN and REC AN had significantly higher mean baseline TRP/LNAA (tryptophan/large neutral amino acids) ratios compared with CW. In contrast to placebo, the ATD challenge demonstrated a significantly greater reduction in the TRP/LNAA ratio for ILL AN (-95%) and REC AN (-84%) compared with CW (-70 %). Both the ILL AN and REC AN had a significant reduction in anxiety on the ATD day compared with the placebo day.

DISCUSSION

These data demonstrate that a dietary-induced reduction of TRP, the precursor of serotonin, is associated with decreased anxiety in people with AN. Restricting dietary intake may represent a mechanism through which individuals with AN modulate a dysphoric mood.

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.

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.