Wednesday, 5 October 2016

Anorexia Nervosa

Anorexia nervosa is a form of eating disorder of bio-psychological origin, and whose effects are characterized by low weight, under-nutrition, and reduction of body mass, which results in thinning. The psychological basis of the condition is fear of weight gain, which the affected person associates with an increase in body mass and loss of body shape. The condition predominantly affects females, and its etiology is still unknown. Nonetheless, affected females usually consider themselves to be overweight, and thus use food restriction as a way of reducing their apparent weight, in addition to restoring their body shape by reducing the amount of subcutaneous fat tissue and adipose tissue around the body. However, food restriction leads to under-nutrition, and this predisposes affected females to nutritional deficiencies - and their related ill-effects (Bühren et al, 2014). Thus, there is need to understand the condition in order to manage it.  The condition can be conceptualized using a biopsychosocial model. This model is described below.
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Biopsychosocial Model
The model has three distinct aspects which are explained hereafter. The biological aspect of the model is used to define the probable etiological mechanism of the condition. Then, the psychological aspect of the model serves to correlate the condition to the psychological functioning of the affected individual. Finally, the sociological aspect of the model serves to relate the condition to the surrounding environment, and predisposing environmental factors including media influence and peer pressure. Each of these three aspects of the model is discussed below.
Biological Aspect
In 2012, the condition was estimated to affect about 0.4% of all females worldwide, while its prevalence among the global male population was estimated to be 0.04% (Hughes, 2012). The exact etiology of the condition is presently unknown but studies have shown that the factors described hereafter precipitate its development.  Genetics is a predisposing factor, as the condition exhibits a highly heritable pattern, with the daughter of an affected mother being more likely to develop the condition than a daughter born to an unaffected mother (Bühren et al, 2014).  However, a study done by Hughes, and published in 2012, relates this observation to childhood depression and anxiety. According to Hughes, a mother who was once affected by the condition is more likely to pressurize her daughter to value a specific body shape, and even castigate her if she appears to be gaining weight (2012). Thus, the affected daughter becomes nervous and anxious as she attempts to mold into the body model that her mother values and this ultimately leads to food restriction, thus anorexia nervosa.
Obstetric complications related to prenatal conditions do lead to the development of the condition. The implicated prenatal complications include eclampsia, pre-eclampsia, maternal anemia, placental infraction, maternal diabetes mellitus, and neonatal cardiac and cardiovascular abnormalities (Hughes, 2012). In a study done by Bühren et al, and published in 2014; it was shown that neonatal complications do sometimes engender an unhealthy form of harm avoidance, which ultimately leads to anorexia nervosa.
Neuroendocrine dysregulation has also been cited as one the mechanisms that leads to the development of the condition (Bühren et al, 2014). In a quantitative research published in 2016 by Geisler et al, it was shown that the condition develops following dysregulation of the neuroendocrine pathways that regulate hunger and satiety centers in the brain. The implicated hormones are ghrelin, orexin, neuropeptide Y, and leptin. Subsequent to the neuroendocrine dysregulation, these hormones operate in concert in the brain system to produce early satiety as well as significantly increase the threshold of hunger (Geisler et al., 2016).
Infections, especially those that affect the gastrointestinal tract are also known to precipitate the development of anorexia nervosa (Bühren et al, 2014). In a study done by Fragiskos Gonidakis, Vasilliki Kravvariti, and Eleftheria Varsou, and published in 2015, the role of gastrointestinal infections and diseases in precipitating the development of both anorexia nervosa and bulimia were documented.  Gastrointestinal infections, especially those caused by mycoplasma and streptococcus bacteria, do reduce the absorptive capacity of the digestive tract, and thus less digested food is absorbed and assimilated into the body, hence a reduction in body mass due to the rate of anabolism being slower than the rate of catabolism (Gonidakis, Kravvariti & Varsou, 2015). This ultimately results in anorexia.
Psychological Aspect
According to a study done by Buhren et al, anorexia nervosa results from abnormal psychological functioning of the affected female (2014). The study relates anorexia nervosa to both cibophobia and sitophobia, which are considered as the differential diagnoses of anorexia nervosa (Buhren et al., 2014). Cibophobia and sitophobia are terms used to describe an irrational aversion to food, and fear of eating respectively. Moreover, anorexia nervosa has also been shown to be associated with low self-esteem and a feeling of low self-worth; which is partly caused by peer pressure and detrimental media pressure (Ehrlich et al., 2015).
Sociological Aspect
The environment that surrounds the affected female does contribute significantly to the development of the condition. According to a study done by Ehrlich et al, the rate of diagnosis of the condition has increased significantly after the 1960, and this is related to the internalization of media-approved body ideals. The internalization of non-natural ideals has made a lot of young females vulnerable to media pressure, as well as peer pressure, which ultimately drives them to restrict their food intake so as reduce their body mass, and thus decrease their body volume and, hence attain the ideal body shape and appearance (Ehrlich et al., 2015). This results in the development of anorexia nervosa.
The biopsychosocial model of anorexia nervosa aims to provide a framework that relates the probable etiologies of the condition to its effects and outcomes. The model encompasses three distinct aspects; biological, psychological and sociological aspects. The biological aspects of the model relate anorexia nervosa to its organic origins. The psychological and sociological aspects relate the condition to the psychological make-up of the individual, and psychological functioning as well as how the individual relates with environmental strain.
Bühren, K., Schwarte, R., Fluck, F., Timmesfeld, N., Krei, M., Egberts, K., ... & Herpertz‐
            Dahlmann, B. (2014). Comorbid psychiatric disorders in female adolescents with first‐
            onset anorexia nervosa. European Eating Disorders Review22(1), 39-44.
Ehrlich, S., Geisler, D., Ritschel, F., King, J. A., Seidel, M., Boehm, I., ... & Smolka, M. N.
            (2015). Elevated cognitive control over reward processing in recovered female patients
            with anorexia nervosa. Journal of Psychiatry & Neuroscience: JPN40(5), 307.
Geisler, D., Borchardt, V., Lord, A. R., Boehm, I., Ritschel, F., Zwipp, J., ... & Walter, M.
            (2016). Abnormal functional global and local brain connectivity in female patients with
            anorexia nervosa. Journal of Psychiatry & Neuroscience: JPN41(1), 6.
Gonidakis, F., Kravvariti, V., & Varsou, E. (2015). Sexual function of women suffering from
            anorexia nervosa and bulimia nervosa. Journal of Sex & Marital Therapy41(4), 368-
Hughes, E. K. (2012). Comorbid depression and anxiety in childhood and adolescent anorexia
            nervosa: Prevalence and implications for outcome. Clinical Psychologist16(1), 15-24.

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