Biological Explanation for Anorexia Nervosa Essay

Incidences of Anorexia Nervosa have appeared to increase sharply in the USA, UK and western European countries since the beginning of the 60s (Gordon, 2001). The increasing prevalence of the disease has led the World Health Organisation to declare eating disorders a global priority area within adolescent mental health (Becker et al. 2011). Anorexia has in many ways become a modern epidemic (Gordon, 2000) and with a mortality rate of 10% per decade (Gorwood et al. 2003), the highest of any mental disorder (Bulik et al. 2006), it is an epidemic that social and biological scientists have been working tirelessly to understand.

Parallel to this, the focus on genetics is Particularly convicted in twin studies, which establish a comparison between monozygotic twins that are identical and dizygotic twins, which are opposingly non-identical. This distinction can be identified in Torgersens study, which compared MZ and same sex DZ twins where one proband had an anxiety disorder, and it was discovered that such disorders were 5x more frequent in MZ twin pairs, who mutually shared identical genetics.

It is believed that faulty genes can cause some disorders that have a psychological effect. A way in which this can be tested is by doing studies on twins as they have the similar genetics. McGuffin et al did a study in 1996 where they compared 109 sets of twins in order to investigate how likely each twin was to develop depression. They looked at the concordance rates for depression in MZ and DZ twins, they expected that MZ twins either both have depression or neither have depression. So therefore its expected to find a higher concordance for depression in MZ twins that in DZ twins. The results showed that if one non identical twin developed depression that there was a 20% likelihood that the other would too, in identical twins this rose to 46%. This study therefore proves that genetics can have a massive impact on abnormality.

While it has been long assumed that bulimia and anorexia have stemmed from insecurities and poor choices; DNA, genetics, endorphins, cholecystokinin, and CCK levels, among other things, are all important deciding factors of whether or not someone will be plagued with the diseases. Among the two, bulimia nervosa has had the most backed research on what could be the cause and nature of the disease. Bulimia Nervosa is a binge eating disorder. During these binges the participants eat without their food hormone receptors turning off resulting in them eating more than what would be FDA approved. After one of their binges they quickly purge themselves in a hope to lose the weight they gained during their binges. Pinpointing the causes of it have proven difficult because the disorder has both mental and psychical components, and it develops in

The inaccurate obsession with food seems to be the cause of bulimia; however, the inaccurate obsession with weight seems to be the cause of anorexia. A majority of research suggest that the media is responsible for this, due to the fact they idolize the thin, slender figure. For bulimics, the delight of binging comes at the cost of extreme guilt which can only be resolved by purging; a never ending cycle. For anorexics, these thin messages on the media can make them feel shameful and hate to look at their own body, which makes food the sworn enemy. In one research article it was proposed that individuals with an external locus of control (believing that their lives are determined by outside forces such as fate and other people) were found to exhibit more of the bulimic and anorexic traits than those individuals who had an internal locus of control (believing that one controls his/her own fate) (Fouts and Vaughn, 2002).

This can also be accounted for distant relatives who are unlikely to share the same environment. We can therefore assume that to confirm a genetic base for schizophrenia, research must separate genetic influences from environmental influences. In order to do this, researchers must look at the evidence presented through twin studies. A set of MZ twins share the same genes, therefore if only one of the develops schizophrenia, it is more likely to be through environmental factors.

Another study strategy to demonstrate the genetic component of a disease, and help to discriminate it from the environmental component is the twin study, which compares the correlation to the disease between monozygotic (MZ), with concordance among dizygotic twins (DZ). This type of epidemiological study 7parte the assumption that twins MZ and DZ suffer similar environmental influence, however, the MZ are genetically identical while the DZ not necessarily presenting genetic identity as similar as two brothers generated at different

Along with Florida State University psychology professor Pamela Keel, PhD, Klump is now using those findings to examine how natural changes in ovarian hormone levels may contribute to bulimic behaviors in twins. Preliminary analyses suggest that heritability influences disordered eating most when estrogen levels are at their highest. Klump is also involved with a study of the genetic underpinnings of anorexia conducted by University of North Carolina at Chapel Hill psychologist Cynthia Bulik, PhD, and other researchers from around the world. As part of a 13-country Genetic Consortium for Anorexia Nervosa, they plan to conduct the largest ever genomewide association study for the disorder, pulling together resources and DNA samples of more than 4,000 females with anorexia and 4,000 controls. However, new and as-yet-unpublished fMRI brain imaging work by Oregon Research Institute psychologist Eric Stice, PhD, suggests that in some females, bulimia may be hard-wired. Stice examined brain activation among 33 female adolescents and 43 young women after they tasted a chocolate milkshake. Over a one-year follow-up period, he found that those who showed greater activation of key reward regions in the brain—particularly the gustatory cortex, somatosensory cortex and striatum—reported increases in bulimic behavior. Similar research by Columbia University's Rachel Marsh, PhD, shows that the

The Academy for Eating Disorders, AED, takes the position that eating disorders are “biologically based” (Klump, 2009, p. 97) due to the findings from twin studies research. This position is supported by the longitudinal study conducted by Patton and colleagues (1999), in which they hypothesize there are biological predictors in the development of eating disorders among adolescent girls

Firstly a biological approach was studied by Holland (1988) on genetic concordance between identical twins and non-identical twins. Holland was trying to discover the connection between anorexia and genetics through twins. Holland's study consisted of taking pairs of Monozygotic (identical) and Dizygotic (non-identical) with one of the twins suffering from anorexia;

Many researchers have found that genetics are linked to eating disorders. Studies have shown that genetics are responsible for 56% of the onset of bulimia, anorexia, and binge eating (Johnson and Bulik). The Eating Disorder Review said that a person is four times more likely to become bulimic and twelve times more likely to become anorexic if he or she has a sister or mother who suffers from an eating disorder (Kittleson 44). Studies of identical twins have also

The Diagnostic and Statistical Manuel of Mental Disorders 5th edition defines anorexia nervosa as an eating disorder characterized by self-starvation and excessive weight loss; it is a serious and potentially life-threatening disorder. According to the DSM 5, the typical diagnostic symptoms of anorexia nervosa are: dramatic weight loss leading to significant low body weight for the individuals age, sex, and health; preoccupation with weight; restriction of food, calories and fat; constant dieting; feeling “fat” or overweight despite weight loss and fear about gaining weight or being “fat.” Many individuals with anorexia nervosa deny feeling hungry and often avoid eating meals with others, resulting in withdrawal from usual friends and activities

Researchers have discovered an area on chromosome 1 that appears to be associated with an increased susceptibility to anorexia. Others can suffer from psychological reasons. People that feel low self-worth sometimes become anorexic to make themselves feel better. Anorexia’s may have an extreme drive for perfectionism, which means they may never thing they’re thin enough. A lot of people suffer because of sociocultural reasons. The media is filled with images of thin models and actors, which associates success and worth with being thin. Peer pressure from friends, coworkers, and classmates also causes some people to feel there not fitting it.

a. According to Doctor Thomas Insel and director of NIMH, scientist and researchers have always been interested in the role of genetics on eating disorders but they are still far away from knowing specific geneses that causes eating disorder

Eating disorders tend to run in families and female relatives are the most often to be affected. Some recent studies from researchers found that mothers who are too concerned about their children’s weight and appearance, it may put them at increased risk of developing an eating disorder. (Hoffman). Ultimately, genetic research may prove to be the key to unlocking our understanding of environmental risk factors for eating disorders (Mazzeo and Bulik). Multiple studies have been undertaken to that show possible genetic likeliness toward developing eating disorders as a result of inheritance (News Medical).