Orbitofrontal cortex volume and brain reward response in obesity.

BACKGROUND/OBJECTIVES: What drives overconsumption of food is poorly understood. Alterations in brain structure and function could contribute to increased food seeking. Recently, brain orbitofrontal cortex (OFC) volume has been implicated in dysregulated eating but little is known how brain structure relates to function. SUBJECTS/METHODS: We examined obese (n=18, age=28.7±8.3 years) and healthy control women (n=24, age=27.4±6.3 years) using a multimodal brain imaging approach. We applied magnetic resonance and diffusion tensor imaging to study brain gray and white matter volume as well as white matter (WM) integrity, and tested whether orbitofrontal cortex volume predicts brain reward circuitry activation in a taste reinforcement-learning paradigm that has been associated with dopamine function. RESULTS: Obese individuals displayed lower gray and associated white matter volumes (P<0.05 family-wise error (FWE)- small volume corrected) compared with controls in the orbitofrontal cortex, striatum and insula. White matter integrity was reduced in obese individuals in fiber tracts including the external capsule, corona radiata, sagittal stratum, and the uncinate, inferior fronto-occipital, and inferior longitudinal fasciculi. Gray matter volume of the gyrus rectus at the medial edge of the orbitofrontal cortex predicted functional taste reward-learning response in frontal cortex, insula, basal ganglia, amygdala, hypothalamus and anterior cingulate cortex in control but not obese individuals. CONCLUSIONS: This study indicates a strong association between medial orbitofrontal cortex volume and taste reinforcement-learning activation in the brain in control but not in obese women. Lower brain volumes in the orbitofrontal cortex and other brain regions associated with taste reward function as well as lower integrity of connecting pathways in obesity (OB) may support a more widespread disruption of reward pathways. The medial orbitofrontal cortex is an important structure in the termination of food intake and disturbances in this and related structures could contribute to overconsumption of food in obesity.

Altered structural and effective connectivity in anorexia and bulimia nervosa in circuits that regulate energy and reward homeostasis.

Anorexia and bulimia nervosa are severe eating disorders that share many behaviors. Structural and functional brain circuits could provide biological links that those disorders have in common. We recruited 77 young adult women, 26 healthy controls, 26 women with anorexia and 25 women with bulimia nervosa. Probabilistic tractography was used to map white matter connectivity strength across taste and food intake regulating brain circuits. An independent multisample greedy equivalence search algorithm tested effective connectivity between those regions during sucrose tasting. Anorexia and bulimia nervosa had greater structural connectivity in pathways between insula, orbitofrontal cortex and ventral striatum, but lower connectivity from orbitofrontal cortex and amygdala to the hypothalamus (P<0.05, corrected for comorbidity, medication and multiple comparisons). Functionally, in controls the hypothalamus drove ventral striatal activity, but in anorexia and bulimia nervosa effective connectivity was directed from anterior cingulate via ventral striatum to the hypothalamus. Across all groups, sweetness perception was predicted by connectivity strength in pathways connecting to the middle orbitofrontal cortex. This study provides evidence that white matter structural as well as effective connectivity within the energy-homeostasis and food reward-regulating circuitry is fundamentally different in anorexia and bulimia nervosa compared with that in controls. In eating disorders, anterior cingulate cognitive-emotional top down control could affect food reward and eating drive, override hypothalamic inputs to the ventral striatum and enable prolonged food restriction.

Development of a novel SCADA system for laboratory testing.

This document summarizes the supervisory control and data acquisition (SCADA) system that allows communication with, and controlling the output of, various I/O devices in the renewable energy systems and components test facility RESLab. This SCADA system differs from traditional SCADA systems in that it supports a continuously changing operating environment depending on the test to be performed. The SCADA System is based on the concept of having one Master I/O Server and multiple client computer systems. This paper describes the main features and advantages of this dynamic SCADA system, the connections of various field devices to the master I/O server, the device servers, and numerous software features used in the system. The system is based on the graphical programming language "LabVIEW" and its "Datalogging and Supervisory Control" (DSC) module. The DSC module supports a real-time database called the "tag engine," which performs the I/O operations with all field devices attached to the master I/O server and communications with the other tag engines running on the client computers connected via a local area network. Generic and detailed communication block diagrams illustrating the hierarchical structure of this SCADA system are presented. The flow diagram outlining a complete test performed using this system in one of its standard configurations is described.

MCMI-II personality scale scores among women with anorexia nervosa or bulimia nervosa.

Issues of personality psychopathology among women who experience eating disorders are of interest to both researchers and clinicians. The MCMI-II (Millon, 1987) may be a useful instrument for use with this population as it measures 13 categories of personality psychopathology. It is surprising to note that no report of MCMI-II scores among women with eating disorders has been published. In this study, adult women with anorexia nervosa, restricting type (n = 27) or binge-eating/purging type (n = 33), or bulimia nervosa, purging type (n = 105), completed the MCMI-II at initial assessment. Significant differences were found as a function of diagnostic group and the overall pattern of elevated scores illustrated prominent personality features of the sample as a whole. Results are discussed with regard to congruence with previous research and the potential implications for understanding the psychodynamics of eating disorders.

Body dissatisfaction, bulimia, and depression among women: the mediating role of drive for thinness.

OBJECTIVE: Past research has called into question the apparent relationship between body dissatisfaction and bulimia among women once effects of depression are statistically controlled. We further investigated interrelations among body dissatisfaction, depression, and bulimia, as well as considered individual differences in drive for thinness, within two samples of young adult women. METHOD: The first sample included women diagnosed with anorexia nervosa (n = 91) or bulimia nervosa (n = 142), whereas the second sample included college student women (N = 228). Respondents completed self-report measures of bulimia, drive for thinness, negative affect, and body dissatisfaction. RESULTS: At the univariate level, all of the above constructs were significantly related to body dissatisfaction. In multiple regression analyses using depression and bulimia as predictors of body dissatisfaction, both were uniquely related to body dissatisfaction. These findings were similar to the results of previous research. However, when drive for thinness was added to the regression equations, drive for thinness was a unique predictor of body dissatisfaction whereas bulimia was not (neither was depression among college women). DISCUSSION: Bulimia, depression, and body dissatisfaction may be the results of incorporation of cultural standards regarding thinness, hence the apparent relationships among these variables. The role of drive for thinness in the pathogenesis of depression and body dissatisfaction among women needs to be investigated further.

Assessment and treatment of bulimia nervosa.

Bulimia nervosa is characterized by binge eating and inappropriate compensatory behaviors, such as vomiting, fasting, excessive exercise and the misuse of diuretics, laxatives or enemas. Although the etiology of this disorder is unknown, genetic and neurochemical factors have been implicated. Bulimia nervosa is 10 times more common in females than in males and affects up to 3 percent of young women. The condition usually becomes symptomatic between the ages of 13 and 20 years, and it has a chronic, sometimes episodic course. The long-term outcome has not been clarified. Other psychiatric conditions, including substance abuse, are frequently associated with bulimia nervosa and may compromise its diagnosis and treatment. Serious medical complications of bulimia nervosa are uncommon, but patients may suffer from dental erosion, swollen salivary glands, oral and hand trauma, gastrointestinal irritation and electrolyte imbalances (especially of potassium, calcium, sodium and hydrogen chloride). Treatment strategies are based on medication, psychotherapy or a combination of these modalities.

Sexual functioning and attitudes of eating-disordered women: a follow-up study.

The sexual experiences and attitudes of eating disorder patients are receiving increased professional attention. However, empirical work in this area has generally focused on these patients at the point of initial evaluation. In the current study we report the results of a follow-up questionnaire completed by women who had been treated in our clinic (N = 42) for either anorexia nervosa (restricting type) or bulimia nervosa (purging type). We found that former anorectic patients were less likely to return the questionnaire and, of those who did, there was a trend toward anorectic women's being less likely to be in a romantic/erotic relationship. Almost all of the women had engaged in sexual intercourse, and former anorectic patients did not differ from bulimics with regard to age at first coitus. Anorectics were less likely than bulimics to have engaged in masturbation and also scored lower on a measure of sexual esteem. Although there were no differences between the two groups with regard to current level of sexual functioning, erotophobia/erotophilia, or sexual satisfaction, the women in our sample exhibited less sexual interest and more negative affect during sex than did a normative sample. Also, nearly 40% of our sample indicated clinically significant levels of sexual discord with their current partner. Results are discussed with regard to prior research, interventions, and further study.

Obsessive-compulsive disorder, trichotillomania, and anorexia nervosa: a case report.

We report a case study of an 18-year-old female who presented with symptoms associated with several discrete diagnostic syndromes: obsessive-compulsive disorder, trichotillomania, major depression, and anorexia nervosa. Improvement in each occurred after treatment with the serotonin selective reuptake inhibitor, fluoxetine, suggesting that such syndromes share a common serotonin neurotransmitter disturbance. Furthermore, the combined effects of medication and psychotherapy resulted in improvement in assertiveness, sense of security, self-worth, flexibility, and self-regulation. We discuss the pharmacological and psychotherapeutic implications of possible psychophysiologic similarities among the previously mentioned syndromes.

Death due to alcoholic complications in a young woman with a severe eating disorder: a case report.

OBJECTIVE: Recently, a good deal of attention has been focused on alcoholism and eating disorders as comorbid conditions. Early identification of biologic, psychologic, and sociocultural factors that contribute to comorbid alcoholism and eating disorders may improve the outcome for such patients. METHOD: The following case report is of a 26-year-old woman who developed a severe eating disorder in her early teens that was followed by alcoholism. RESULTS: The combination of eating disorder and alcoholism in this patient led to approximately 70 hospitalizations for medical complications of her alcoholism. This paper chronicles her last few living months including her death due to alcoholic complications.