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eating disorders,in psychology, disorders in eating patterns that comprise four categories: anorexia nervosa, bulimia, rumination disorder, and pica. Anorexia nervosa is characterized by self-starvation to avoid obesity. People with this disorder believe they are overweight, even when their bodies become grotesquely distorted by malnourishment. Bulimia is characterized by massive food binges followed by self-induced vomiting or use of diuretics and laxatives to avoid weight gain. Some anorexic patients combine bulimic purges with their starvation routine. These disorders generally afflict women—particularly in adolescence and young adulthood—and are much less common among men. Some researchers believe that anorexia and bulimia are caused by chemical imbalances in the brain; one study has linked bulimia to deprivation of tryptophan, an amino acid used by the body to make the neurotransmitter serotonin. Others contend that these disorders are rooted in societal ideals that value slenderness. Rumination disorder generally occurs during infancy, and involves repeated regurgitation accompanied by low body weight. Infants suffering from rumination disorder may re-ingest the regurgitated food. Pica, also found primarily among infants, is characterized by eating various non-nutritive substances like plaster, paint, or leaves. Obesityobesity,
condition resulting from excessive storage of fat in the body. Obesity is now usually defined using a formula known as the body mass index (BMI), in which weight (in kilograms) is divided by height (in meters) squared.
..... Click the link for more information. is not generally considered an eating disorder, since its causes tend to be physiological.
Disorders characterized by abnormal eating behaviors and beliefs about eating, weight, and shape. The three major diagnoses are anorexia nervosa, bulimia nervosa, and binge eating disorder. In addition, there are many cases of abnormal eating that have only some of the features required for an eating disorder diagnosis; these cases are classified as eating disorders not otherwise specified. Obesity is classified as a general medical condition and not as an eating disorder (a psychiatric condition) because it is not consistently associated with psychological or behavioral problems.
There are also three childhood eating disorders: (1) Pica is a persistent pattern of eating nonnutritive substances in infants or young children. (2) Rumination disorder involves repeated regurgitation and rechewing of food. This behavior is not the result of a gastrointestinal or medical condition; the partially digested food comes back into the mouth without any observable nausea, disgust, or attempt to vomit. (3) Feeding disorder of infancy or early childhood is the persistent failure to eat adequately, as reflected in insufficient weight gain for age. Pica and rumination disorder are thought to be uncommon and frequently associated with developmental delays and mental retardation. Perhaps half of the pediatric hospitalizations for inadequate weight gain (which constitute 1–5% of all pediatric hospitalizations) may be due to feeding disorder of infancy or early childhood.
Anorexia nervosa is characterized by a refusal to maintain a minimal normal body weight (defined as 15% below average weight for height), an intense fear of becoming fat, and, if female, amenorrhea for at least 3 months. The majority of cases of anorexia nervosa are classified as restricting type; these individuals achieve abnormally low weight by severely dieting, fasting, and often by exercising compulsively. In severe cases, patients refuse to eat and can die of starvation or severe medical complications. Another subtype of anorexia nervosa is binge eating/purging type. Despite being emaciated or dangerously thin, persons with anorexia nervosa perceive themselves as overweight (distorted body image), deny the seriousness of their condition, and have an intense fear of becoming fat.
Anorexia nervosa occurs in roughly 1% of adolescent and young adult females. Most cases (90%) are female, and the majority are Caucasian and come from middle-class or higher socioeconomic groups. Anorexia nervosa is more prevalent in industrialized countries that share western views regarding thinness as an ideal. It develops most frequently during adolescence.
Persons with anorexia nervosa frequently manifest symptoms of depression and anxiety. The restricting type of anorexia nervosa is associated with obsessionality, rigidity, perfectionism, and overcontrol, whereas the binge/purge subtype is associated with greater mood instability and impulsivity across a wide range of areas, including substance abuse.
Although some cases of anorexia nervosa show no evidence of medical problems, prolonged starvation affects most organ systems, and a wide array of medical problems tend to be present. Long-term mortality from anorexia nervosa is estimated at 5–10% with most deaths resulting from starvation, cardiac events, or suicide.
The causes of anorexia nervosa are not yet understood but are likely to involve a complex combination of genetic, familial, psychological, and sociocultural factors. The onset of anorexia nervosa tends to follow a period of dieting and is frequently triggered by a stressful life events or transitions.
Since the starvation and weight loss can be life-threatening, initial treatment efforts need to focus on weight gain and the reestablishment of regular eating patterns. Inpatient hospitalization is frequently necessary. Although significant psychological issues tend to be present, it is generally ineffective to address these until weight has been stabilized. Once weight gain is achieved, psychotherapies can become useful. Relapse rates are high. See Psychotherapy
Bulimia nervosa is characterized by recurrent episodes of binge eating (eating large amounts of food while experiencing a subjective sense of lack of control over the eating), the regular use of extreme weight compensatory methods (for example, self-induced vomiting), and dysfunctional beliefs about weight and shape that unduly influence self-evaluation or self-worth.
Bulimia nervosa occurs in roughly 2% of adolescents and adults. It is most common in females (90% of cases), Caucasians, and middle-class or higher socioeconomic groups. The prevalence of bulimia has increased over the past few decades, and is also becoming more common in non-Caucasian groups.
Persons with bulimia nervosa have high rates of depression, anxiety, and substance abuse problems. Although this condition is less dangerous than anorexia nervosa, medical complications can occur. Dental erosion and periodontal problems are common. Electrolyte imbalance and dehydration can result in serious medical complications, including cardiac arrhythmias. In rare cases, esophageal bleeding and gastric ruptures occur.
Bulimia nervosa is likely to result from a combination of genetic, familial, psychological, and sociocultural factors. Although many persons have weight and diet concerns, the development of bulimia is thought to arise only in vulnerable individuals and usually after a stressful event. Bulimia nervosa is a self-maintaining vicious cycle.
Bulimia nervosa can often be treated successfully with outpatient therapies. Cognitive behavioral therapy and interpersonal psychotherapy have been found to be most effective for reducing binge eating and vomiting and improving associated concerns such as depression, self-esteem, and body image. These two therapies also have the best results over the long term. Certain types of pharmacotherapy, notably antidepressant medications, are also effective.
Binge eating disorder
Binge eating disorder is characterized by recurrent episodes of binge eating but, unlike bulimia nervosa, no extreme weight control behaviors (purging, laxatives, fasting) are present. Persons with binge eating disorder have chaotic eating patterns and frequently overeat as well as binge.
Although obesity is not required for the diagnosis, many people with binge eating disorder are overweight. Binge eating disorder is estimated to occur in 3% of the general population but in roughly 30% of obese persons. Binge eating disorder occurs most frequently in adulthood, affects men nearly as often as women, and occurs across different ethnic groups.
Obese binge eaters are characterized by higher levels of psychiatric problems (depression, anxiety, substance abuse) and psychological problems (poor self-esteem, body image dissatisfaction) than non-binge eaters and closely resemble persons with bulimia nervosa. Overweight persons with binge eating disorder are at high risk for further weight gain and weight fluctuations and associated medical complications. The etiology of binge eating disorder is unknown.
Cognitive behavioral therapy is effective for reducing binge eating and improving associated concerns such as depression, self-esteem, and body image, but does not seem to result in weight loss. There is some evidence that behavioral weight control treatment can reduce binge eating and facilitate weight loss. Antidepressant medications appear to reduce binge eating but do not produce weight loss; relapse is rapid after discontinuation of the medication. See Affective disorders