Eating is so central to human nature that disturbances in normal eating behavior can be very difficult to understand. An eating disorder is a psychological disorder in which the basic function of eating is disturbed. This disorder occurs when an individual (usually female) suffers extreme disturbances in eating behavior caused by an obsessive (and irrational) fear of gaining weight.
Anorexia nervosa
Anorexia nervosa is a serious condition marked by an inability to maintain a normal healthy body weight. A person with anorexia weighs less than 85% of ideal body weight. Psychologists measure their patients weight by calculating body mass index, or BMI. Anorexia nervosa is 9 times more common in females than males. Amenorrhea is a common criterion of anorexia in women which causes women and girls who have begun menstruating to stop having menstrual periods for at least 3 consecutive months. The typical age of onset for anorexia nervosa is adolescence although more and more cases are being reported in childhood and older adulthood.
Anorexia nervosa is a visible eating disorder where it is noticeable that the patients are thin and they cover up their emaciation (severe underweight) by wearing layers of clothes or otherwise hiding their bodies. Even in the most extreme phases of emaciation, individuals fear weight gain. They have a distorted image of their body, often believing that they are fat and need to lose more weight. Anorexic individuals place excessive importance on weight and shape as a measure of self-evaluation. In fact, their weight becomes a determining factor for their sense of worth and self-esteem. There is also denial of illness. Even when facing severe medical complications, individuals with anorexia nervosa insist that everything is fine.
Anorexia nervosa has two subtypes, restricting and binge eating/purging. People with the restricting type of anorexia nervosa simply refuse to eat and/ or engage in excessive exercise as a way of preventing weight gain. In the binge eating/purging subtype, individuals may engage in either binge eating (eating an unusually large amount of food in a short period of time and feeling out of control), purging (using self-induced vomiting, laxatives, or diuretics [water pills]), or both behaviors.
Bulimia Nervosa
Bulimia nervosa is an invisible eating disorder where there is a repeated pattern of eating an excessive amount of food in a very short period of time (bingeing) and then engaging in behaviors to compensate for the extreme food intake and to avoid weight gain (purging). the characteristic feature of a binge is feeling out of control. The pattern of binge eating also varies. The frequency can range from occasionally to a few times per week to 20 or 30 times per day. Like anorexia nervosa, bulimia nervosa is around 9 times more common in females than males. The incidence of bulimia has increased since 1960 and is more common in urban than rural populations.
The physical symptoms of bulimia nervosa Corrosion of dental enamel by exposure to stomach acids during vomiting, Dehydration and anemia, Irritation and enlargement of salivary glands due to frequent vomiting, Menstrual irregularities, Electrolyte imbalances.
The DSM-IV-TR distinguishes between two kinds of bulimia: purging and non-purging types. The purging subtype of bulimia nervosa includes those individuals who vomit or use laxatives, diuretics, or other agents. The non-purging subtype includes those individuals who compensate via fasting or excessive exercise. People with bulimia tend to be more impulsive (acting before thinking) and have higher novelty-seeking (stimulus or sensation-seeking) behavior.
Binge eating Disorder
The DSM-5 created a new diagnostic category called other specified feeding or eating disorder for eating behaviors that are disordered but do not meet diagnostic criteria for either anorexia or bulimia nervosa. The DSM-5 other specified feeding or eating disorder category includes disorders like atypical anorexia nervosa, bulimia nervosa of low frequency and/or limited duration, night eating syndrome. Binge eating disorder (BED) is characterized by regular binge eating behavior but without the regular compensatory behaviors that are part of bulimia nervosa. Because BED is a recent addition to the DSM, little is known about its morbidity and mortality. BED is associated with obesity as well as depression, anxiety, and personality pathology.
References
Beidel, B., Cynthia, M., & Stanley, M. A. (2017). Abnormal Psychology. Pearson Education.
Getzfeld, A. R. (2010). Essentials of abnormal psychology. John Wiley & Sons.
Hansell, J. H., & Damour, L. K. (2007). Abnormal psychology. Wiley Global Education.
Nolen-Hoeksema, S., & Jennings, H. (2001). Abnormal psychology. New York: McGraw Hill.