Eating disorders are psychological illnesses defined by abnormal eating habits that may involve either insufficient or excessive food intake to the detriment of an individual’s physical and mental health. Bulimia nervosa and anorexia nervosa are the most common specific forms of eating disorders.
Bulimia nervosa is a disorder characterized by binge eating and purging. Purging can include self-induced vomiting, over-exercising, and the usage of diuretics, enemas, and laxatives. Anorexia nervosa is characterized by extreme food restriction to the point of self-starvation and excessive weight loss. The extreme weight loss often causes women and girls who have begun menstruating to stop having menstrual periods, a condition known as amenorrhea, although some women who meet the other DSM-5 criteria for anorexia nervosa still report some menstrual activity. The DSM-5 currently specifies two subtypes of anorexia nervosa—the restricting type and the binge/purge type. Those who suffer from the restricting type of anorexia nervosa lose weight by restricting food intake and sometimes by over-exercising, whereas those suffering from the binge/purge type overeat and/or compensate through some method of purging. The difference between anorexia nervosa binge/purge type and bulimia nervosa is the body weight of a person. Those diagnosed with anorexia nervosa binge/purge type are well under a healthy bodyweight, while those with bulimia nervosa may have a body weight that falls within the range from normal to overweight and obese. Though primarily thought of as affecting females (an estimated 5–10 million being affected in the UK), eating disorders affect males as well. An estimated 10 – 15% of people with eating disorders are males (Gorgan, 1999), with an estimated 1 million UK males being affected.
Although eating disorders are increasing all over the world among both men and women, there is evidence to suggest that it is women in the Western world who are at the highest risk of developing them and the degree of westernization increases the risk. Nearly half of all Americans personally know someone with an eating disorder.
The skill to comprehend the central processes of appetite has increased tremendously since leptin was discovered, and the skill to observe the functions of the brain as well. Interactions between motivational, homeostatic and self-regulatory control processes are involved in eating behavior, which is a key component in eating disorders.
The precise cause of eating disorders is not entirely understood, but there is evidence that it may be linked to other medical conditions and situations. Cultural idealization of thinness and youthfulness have contributed to eating disorders affecting diverse populations. One study showed that girls with ADHD have a greater chance of getting an eating disorder than those not affected by ADHD. Another study suggested that women with PTSD, especially due to sexually related trauma, are more likely to develop anorexia nervosa. One study showed that foster girls are more likely to develop bulimia nervosa. Some think that peer pressure and idealized body-types seen in the media are also a significant factor. Some research shows that for certain people there are genetic reasons why they may be prone to developing an eating disorder. Recent studies have found evidence of a correlation between patients with bulimia nervosa and substance use disorders. In addition, anxiety disorders and personality disorders are common occurrences with clients of eating disorders. People with eating disorders may have a dysfunctional hunger cognitive module which causes various feelings of distress to make them feel hungry.
While proper treatment can be highly effective for many suffering from specific types of eating disorders, the consequences of eating disorders can be severe, including death (whether from direct medical effects of disturbed eating habits or from comorbid conditions such as suicidal thinking).
More information about this disorder can be found at WikiPedia.