Exaggerated 5-HT1A but normal 5-HT2A receptor activity in individuals ill with anorexia nervosa.

BACKGROUND: Many studies have found disturbances of serotonin (5-HT) activity in anorexia nervosa (AN). Because little is known about 5-HT receptor function in AN, positron emission tomography (PET) imaging with 5-HT receptor-specific radioligands was used to characterize 5-HT1A and 5-HT2A receptors. METHODS: Fifteen women ill with AN (ILL AN) were compared with 29 healthy control women (CW); PET and [11C]WAY100635 were used to assess binding potential (BP) of the 5-HT1A receptor, and [18F]altanserin was used to assess postsynaptic 5-HT2A receptor BP. [15O] water and PET were used to assess cerebral blood flow. RESULTS: The ILL AN women had a highly significant (30%-70%) increase in [11C]WAY100635 BP in prefrontal and lateral orbital frontal regions, mesial and lateral temporal lobes, parietal cortex, and dorsal raphe nuclei compared with CW. The [18F]altanserin BP was normal in ILL AN but was positively and significantly related to harm avoidance in suprapragenual cingulate, frontal, and parietal regions. Cerebral blood flow was normal in ILL AN women. CONCLUSIONS: Increased activity of 5-HT1A receptor activity may help explain poor response to 5-HT medication in ILL AN. This study extends data suggesting that 5-HT function, and, specifically, the 5-HT2A receptor, is related to anxiety in AN.

Neural correlates of habituation to taste stimuli in healthy women.

Recent studies show that specific regions of the cortex contribute to modulation of appetitive behaviors. The purpose of this study was to determine whether neural response in these regions changes over time when a taste stimulus is administered repeatedly. Such a paradigm may be useful for determining whether altered habituation contributes to disturbed eating behavior. This study used a programmable syringe pump to compare administration of a 10% sucrose solution to distilled water in 11 healthy female subjects using functional magnetic resonance imaging. The stimuli were presented in either a sequential or pseudorandom order. An a priori 'Region of Interest' (ROI) based analysis method was used, with ROIs defined in the prefrontal cortex, insula, amygdala, and hippocampus. To test habituation, activation during the first half of each block was compared with activation during the second half. For the pseudorandom blocks, subjects showed habituation in almost all ROIs to water, but in none to sucrose. By contrast, for sequential blocks, both stimuli produced habituation in taste-related brain regions. These data suggest that habituation patterns in healthy subjects may depend on frequency and regularity of stimulus administration.

Personality traits after recovery from eating disorders: do subtypes differ?

OBJECTIVE: We compared individuals recovered from anorexia (AN) and bulimia nervosa (BN) to determine characteristics that are shared by or distinguish eating disorder (ED) subtypes. METHOD: Sixty women recovered for > or = 1 year from AN or BN were compared with 47 control women (CW). Assessments included the Yale-Brown-Cornell Eating Disorder Scale, the Spielberger State-Trait Anxiety Inventory, the Beck Depression Inventory, the Yale-Brown Obsessive Compulsive Scale, the Temperament and Character Inventory, and Structured Clinical Interviews for DSM-IV. RESULTS: Individuals recovered from an ED had similar scores for mood and personality variables that were significantly higher than the scores for CW. Few recovered subjects had Cluster B personality disorder. Most individuals recovered within 6 years of their ED onset. A latent profile analysis identified an "inhibited" and "disinhibited" cluster based on personality traits. CONCLUSION: A wide range of symptoms persist after recovery and do not differ between subtypes of ED. These findings may aid in identifying traits that create vulnerabilities for developing an ED.

Normal brain tissue volumes after long-term recovery in anorexia and bulimia nervosa.

BACKGROUND: Individuals who are ill with anorexia (AN) and bulimia nervosa (BN) often have increased cerebrospinal fluid (CSF) volumes and decreased total gray and white matter volumes. It is unclear whether such disturbances persist after recovery from an eating disorder. METHODS: Magnetic resonance imaging was performed on 40 women who were long-term recovered (>1 year no binging, purging, or restricting behaviors, normal weight, and menstrual cycles, not on medication) from restricting or binge/purging type AN or BN and 31 healthy control women (CW). Voxel-based morphometry (VBM) was used for data analysis. RESULTS: Recovered AN and BN subgroups were similar to CW in terms of cerebrospinal fluid (CSF) volume as well as total or regional gray or white matter volume. CONCLUSIONS: These findings suggest that structural brain abnormalities are reversible in individuals with eating disorders after long-term recovery.

Altered brain activity in women recovered from bulimic-type eating disorders after a glucose challenge: a pilot study.

OBJECTIVE: It is not known whether individuals with bulimic-type eating disorders have a dysregulation of brain pathways that modulate appetite. Taste plays a role in the regulation of appetite and the purpose of the current study was to determine whether bulimic women have alterations in the physiologic response to the blind administration of glucose. METHOD: To avoid the confounding effects of a current eating disorder, and to assess possibly trait-related disturbances, we studied 10 subjects recovered (> or = 1 year) from a bulimic-type eating disorder and 6 control women. Subjects were administered a solution of glucose or artificial saliva (control solution) in alternating blocks during a functional magnet resonance imaging scan. RESULTS: Individuals who recovered from a bulimic-type eating disorder had significantly lower activation in the right anterior cingulate cortex (ACC; Montreal Neurological Institute [MNI] coordinates x = 8, y = 22, z = 28; cluster size = 18 voxels, T = 5.11, Z-score = 3.78) and in the left cuneus (occipital cortex; MNI coordinates x = -12, y = -78, z = 10; cluster size = 21 voxels, T = 4.27, Z-score = 3.36), when glucose was compared with artificial saliva. CONCLUSION: The ACC plays a role in the anticipation of reward. Individuals with bulimic-type eating disorders may have a reduced reward response to nutrients, and thus may be vulnerable to overeating. However, this is a small sample and the current study will need replication in a larger sample size with investigation of additional regions of interest.

Altered brain serotonin 5-HT1A receptor binding after recovery from anorexia nervosa measured by positron emission tomography and [carbonyl11C]WAY-100635.

CONTEXT: Previous studies have shown that women with anorexia nervosa (AN), when ill and after recovery, have alterations of serotonin (5-HT) neuronal activity and core eating disorder symptoms, such as anxiety. OBJECTIVE: To further characterize the 5-HT system in AN, we investigated 5-HT1A receptor activity using positron emission tomography imaging because this receptor is implicated in anxiety and feeding behavior. DESIGN, SETTING, AND PARTICIPANTS: To avoid the confounding effects of malnutrition, we studied 13 women who had recovered from restricting-type AN (mean age, 23.3 +/- 5.2 years) and 12 women who had recovered from bulimia-type AN (mean age, 28.6 +/- 7.3 years) (>1 year normal weight, regular menstrual cycles, no bingeing or purging). These subjects were compared with 18 healthy control women (mean age, 25.1 +/- 5.8 years). Intervention The 5-HT1A receptor binding was measured using positron emission tomography imaging and a specific 5-HT1A receptor antagonist, [carbonyl-11C]WAY-100635. MAIN OUTCOME MEASURE: Specific 5-HT1A receptor binding was assessed using the binding potential measure. Binding potential values were derived using both the Logan graphical method and compartmental modeling. The binding potential in a region of interest was calculated with the formula: binding potential = distribution volume of the region of interest minus distribution volume of the cerebellum. RESULTS: Women recovered from bulimia-type AN had significantly (P<.05) increased [11C]WAY-100635 binding potential in cingulate, lateral and mesial temporal, lateral and medial orbital frontal, parietal, and prefrontal cortical regions and in the dorsal raphe compared with control women. No differences were found for women recovered from restricting-type AN relative to controls. For women recovered from restricting-type AN, the 5-HT1A postsynaptic receptor binding in mesial temporal and subgenual cingulate regions was positively correlated with harm avoidance. CONCLUSIONS: We observed increased 5-HT1A receptor binding in women who had recovered from bulimia-type AN but not restricting-type AN. However, 5-HT1A receptor binding was associated with a measure of anxiety in women recovered from restricting-type AN. These data add to a growing body of evidence showing that altered serotonergic function and anxiety symptoms persist after recovery from AN. These psychobiological alterations may be trait related and may contribute to the pathogenesis of AN.

An open trial of olanzapine in anorexia nervosa.

BACKGROUND: Recent reports raise the possibility that olanzapine can assist weight gain and improve behavioral symptoms during refeeding in anorexia nervosa. METHOD: Seventeen DSM-IV anorexia nervosa subjects hospitalized between May 1999 and October 2000 were enrolled in open-label treatment with olanzapine for up to 6 weeks. Baseline weight and symptoms were compared to patients' status at the end of treatment. RESULTS: Olanzapine administration was associated with a significant reduction in depression, anxiety, and core eating disorder symptoms, and a significant increase in weight. A comparison with our historical data suggests that subjects in this study had a significantly greater decrease in depression. CONCLUSION: These data lend support to the possibility that olanzapine may be useful in treating anorexia nervosa. However, a controlled trial is necessary to demonstrate that olanzapine is efficacious.

Altered 5-HT(2A) receptor binding after recovery from bulimia-type anorexia nervosa: relationships to harm avoidance and drive for thinness.

Several lines of evidence suggest that a disturbance of serotonin neuronal pathways may contribute to the pathogenesis of anorexia nervosa (AN) and bulimia nervosa (BN). This study applied positron emission tomography (PET) to investigate the brain serotonin 2A (5-HT(2A)) receptor, which could contribute to disturbances of appetite and behavior in AN and BN. To avoid the confounding effects of malnutrition, we studied 10 women recovered from bulimia-type AN (REC AN-BN, > 1 year normal weight, regular menstrual cycles, no binging, or purging) compared with 16 healthy control women (CW) using PET imaging and a specific 5-HT(2A) receptor antagonist, [18F]altanserin. REC AN-BN women had significantly reduced [18F]altanserin binding potential relative to CW in the left subgenual cingulate, the left parietal cortex, and the right occipital cortex. [18F]altanserin binding potential was positively related to harm avoidance and negatively related to novelty seeking in cingulate and temporal regions only in REC AN-BN subjects. In addition, REC AN-BN had negative relationships between [18F]altanserin binding potential and drive for thinness in several cortical regions. In conclusion, this study extends research suggesting that altered 5-HT neuronal system activity persists after recovery from bulimia-type AN, particularly in subgenual cingulate regions. Altered 5-HT neurotransmission after recovery also supports the possibility that this may be a trait-related disturbance that contributes to the pathophysiology of eating disorders. It is possible that subgenual cingulate findings are not specific for AN-BN, but may be related to the high incidence of lifetime major depressive disorder diagnosis in these subjects.

Use of nutritional supplements to increase the efficacy of fluoxetine in the treatment of anorexia nervosa.

OBJECTIVE: Selective serotonin reuptake inhibitor (SSRI) medication does not appear to be effective in ill, malnourished anorexia nervosa (AN) patients. However, it may be effective in preventing relapse after weight restoration. The purpose of this study was to determine whether nutritional supplements could potentiate the effects of fluoxetine in underweight AN subjects. METHOD: Twenty-six subjects with AN participated in a trial of fluoxetine. In a double-blind, placebo-controlled manner, subjects received either nutritional supplements or a nutritional placebo. The nutritional supplement included tryptophan (the precursor of serotonin), vitamins, minerals, and essential fatty acids believed to influence serotonin pathway function. RESULTS: There was no significant difference in weight gain between subjects treated with fluoxetine plus nutritional supplements versus fluoxetine plus a nutritional placebo. Moreover, there were no significant differences between groups on mean changes in anxiety or obsessive and compulsive symptoms. DISCUSSION: The results of this study suggest that supplement strategies are not a substitute for adequate nutrition and are ineffective in increasing the efficacy of fluoxetine in underweight AN subjects.

Olanzapine treatment of anorexia nervosa: a retrospective study.

BACKGROUND: Recent reports raise the possibility that olanzapine, which commonly causes weight gain in non-eating-disordered subjects, assisted weight gain and mood during refeeding in anorexia nervosa (AN) patients. METHODS: Eighteen AN subjects who engaged in open treatment with olanzapine were retrospectively questioned about their response. RESULTS: Subjects reported a significant reduction in anxiety, difficulty eating, and core eating disorder symptoms after taking olanzapine. DISCUSSION: These data lend support to the possibility that olanzapine may be useful in AN patients. CONCLUSION: A controlled trial is necessary to prove that olanzapine is efficacious.

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.

Reduced 5-HT2A receptor binding after recovery from anorexia nervosa.

BACKGROUND: Several lines of evidence suggest that a disturbance of serotonin neuronal pathways may contribute to the pathogenesis of anorexia nervosa (AN). This study applied positron emission tomography (PET) to investigate the brain serotonin 2A (5HT2A) receptor, which could contribute to disturbances of appetite and behavior in AN. METHODS: To avoid the confounding effects of malnutrition, we studied 16 women recovered from AN (REC AN, >1 year normal weight, regular menstrual cycles, no bingeing or purging) compared with 23 healthy control women (CW) using [18F]altanserin, a specific 5-HT2A receptor antagonist on PET imaging. RESULTS: REC AN women had significantly reduced [18F]altanserin binding relative to CW in mesial temporal (amygdala and hippocampus), as well as cingulate cortical regions. In a subset of subjects (11 CW and 16 REC AN), statistical parametric mapping (SPM) confirmed reduced mesial temporal cortex 5HT2A receptor binding and, in addition, showed reduced occipital and parietal cortex binding. CONCLUSIONS: This study extends research suggesting that altered 5-HT neuronal system activity persists after recovery from AN and may be related to disturbances of mesial temporal lobe function. Altered 5-HT neurotransmission after recovery also supports the possibility that this may be a trait-related disturbance that contributes to the pathophysiology of AN.