Anorexia nervosa is an eating disorder characterized by self-starvation, unrealistic fear of weight gain, and conspicuous distortion of body image.
The term anorexia nervosa comes from two Latin words that mean "nervous inability to eat." Anorexics have the following characteristics in common:
- inability to maintain weight at or above what is normally expected for age or height
- intense fear of becoming fat
- distorted body image
- in females who have begun to menstruate, the absence of at least three menstrual periods in a row, a condition called amenorrhea
There are two subtypes of anorexia nervosa: a restricting type, characterized by strict dieting and exercise without binge eating; and a binge-eating/purging type, marked by episodes of compulsive eating with or without self-induced vomiting and/or the use of laxatives or enemas. A binge is defined as a time-limited (usually under two hours) episode of compulsive eating in which the individual consumes a significantly larger amount of food than most people would eat in similar circumstances.
Anorexia nervosa was not officially classified as a psychiatric disorder until the third edition of Diagnostic and Statistical Manual of Mental Disorders (DSM) in 1980. It is, however, a growing problem in the early 2000s among adolescent females. Its incidence in the United States has doubled since 1970. The rise in the number of reported cases reflects a genuine increase in the number of persons affected by the disorder and not simply earlier or more accurate diagnosis. Estimates of the incidence of anorexia range between 0.5 percent and 1 percent of Caucasian female adolescents. Over 90 percent of patients diagnosed with the disorder as of 2001 are female. The peak age range for onset of the disorder is 14 to 18 years. In the 1970s and 1980s, anorexia was regarded as a disorder of upper- and middle-class women, but that generalization is as of 2004 also changing. Studies indicate that anorexia is increasingly common among females of all races and social classes in the United States.
Causes and symptoms
While the precise cause of the disease is not known, anorexia is a disorder that results from the interaction of cultural and interpersonal as well as biological factors.
The rising incidence of anorexia is thought to reflect the present idealization of thinness as a badge of upper-class status as well as of female beauty. In addition, the increase in cases of anorexia includes "copycat" behavior, with some patients developing the disorder from imitating other girls.
The onset of anorexia in adolescence is attributed to a developmental crisis caused by girls' changing bodies coupled with society's overemphasis on female appearance. The increasing influence of the mass media in spreading and reinforcing gender stereotypes has also been noted.
The risk of developing anorexia is higher among adolescents preparing for careers that require attention to weight and/or appearance. These high-risk groups include dancers, fashion models, professional athletes (including gymnasts, skaters, long-distance runners, and jockeys), and actresses.
Genetic and biological influences
Girls whose biological mothers or sisters have or have had anorexia nervosa appear to be at increased risk of developing the disorder.
A number of theories have been advanced to explain the psychological aspects of the disorder. No single explanation covers all cases. Anorexia nervosa has been given the following interpretations:
- Overemphasis on control, autonomy, and independence: Some anorexics come from achievement-oriented families that stress physical fitness and dieting. Many anorexics are perfectionists who are driven about schoolwork and other matters in addition to weight control.
- Evidence of family dysfunction: In some families, a daughter's eating disorder serves as a distraction from marital discord or other family tensions.
- A rejection of female sexual maturity: This rejection is variously interpreted as a desire to remain a child or as a desire to resemble males.
- A reaction to sexual abuse or assault.
- A desire to appear as fragile and nonthreatening as possible: This hypothesis reflects the idea that female passivity and weakness are attractive to males.
- Inability to interpret the body's hunger signals accurately due to early experiences of inappropriate feeding.
Although anorexia nervosa largely affects females, its incidence in the male population is rising in the early 2000s. Less is known about the causes of anorexia in males, but some risk factors are the same as for females. These include certain occupational goals and increasing media emphasis on external appearance in men. Homosexual males are under pressure to conform to an ideal body weight that is about 20 pounds lighter than the standard attractive weight for heterosexual males.
When to call the doctor
A healthcare professional should be contacted if a child or adolescent is suspected of having anorexia nervosa or displays early signs of the disorder, such as the following:
- fear of gaining weight
- distorted body image
- recent weight loss
- restrictive or abnormal eating patterns such as skipping meals or eliminating once-liked foods
- preoccupation with food and dieting
- compulsive exercising
- purging behaviors such as vomiting or using laxatives
- withdrawal from friends and family
- wearing baggy clothes to hide weight loss
Diagnosis of anorexia nervosa is complicated by a number of factors. One is that the disorder varies somewhat in severity from patient to patient. A second factor is denial, which is regarded as an early sign of the disorder. Many anorexics deny that they are ill and are usually brought to treatment by a family member.
Anorexia nervosa is a serious public health problem not only because of its rising incidence, but also because
Most anorexics are diagnosed by pediatricians or family practitioners. Anorexics develop emaciated bodies, dry or yellowish skin, and abnormally low blood pressure. There is usually a history of amenorrhea in female patients, and sometimes of abdominal pain , constipation, or lack of energy. The patient may feel chilly or have developed lanugo, a growth of downy body hair. If the patient has been self-inducing vomiting, she may have eroded tooth enamel or Russell's sign (scars on the back of the hand). The second step in diagnosis is measurement of the patient's weight loss. DSM-IV specifies a weight loss leading to a body weight 15 percent below normal, with some allowance for body build and weight history.
|SOURCE : Diagnostic and Statistical Manual of Mental Disorders IV .|
|1. Refusal to maintain body weight at or above a minimally normal weight for age and height. Body weight is less than 85 percent of what is expected.|
|2. Intense fear of gaining weight or becoming fat, even though patient is underweight.|
|3. Undue influence of body weight or shape on self-evaluation, or denial of the seriousness of current underweight condition.|
|4. Absence of at least three consecutive menstrual cycles in previously menstruating females.|
|Restricting type: No regular episodes of binge-eating or purging (self-induced vomiting or misuse of laxatives, diuretics, or enemas).|
|Binge-eating/purging type: Regular episodes of binge-eating or purging (self-induced vomiting or misuse of laxatives, diuretics, or enemas).|
The doctor will need to rule out other physical conditions that can cause weight loss or vomiting after eating, including metabolic disorders, brain tumors (especially hypothalamus and pituitary gland lesions), diseases of the digestive tract, and a condition called superior mesenteric artery syndrome. Persons with this condition sometimes vomit after meals because the blood supply to the intestine is blocked. The doctor will usually order blood tests, an electrocardiogram, urinalysis, and bone densitometry (bone density test) in order to exclude other diseases and to assess the patient's nutritional status.
The doctor will also need to distinguish between anorexia and other psychiatric disorders, including depression, schizophrenia , social phobia, obsessive-compulsive disorder , and body dysmorphic disorder. Two diagnostic tests that are often used are the Eating Attitudes Test (EAT) and the Eating Disorder Inventory (EDI).
Treatment of anorexia nervosa includes both short- and long-term measures and requires assessment by dietitians and psychiatrists as well as medical specialists. Therapy is often complicated by the patient's resistance or failure to carry out a treatment plan.
Hospitalization is recommended for anorexics with any of the following characteristics:
- weight of 40 percent or more below normal or weight loss over a three-month period of more than 30 lbs (13.6 kg)
- severely disturbed metabolism
- severe binging and purging
- signs of psychosis
- severe depression or risk of suicide
- family in crisis
Hospital treatment includes individual and group therapy as well as refeeding and monitoring of the patient's physical condition. Treatment usually requires two to four months in the hospital. In extreme cases, hospitalized patients may be force-fed through a tube inserted in the nose (nasogastric tube) or into a vein (hyperalimentation).
Anorexics who are not severely malnourished can be treated by outpatient psychotherapy. The types of treatment recommended are supportive rather than insight-oriented and include behavioral approaches as well as individual or group therapy. Family therapy is often recommended when the patient's eating disorder is closely tied to family dysfunction. Self-help groups are often useful in helping anorexics find social support and encouragement. Psychotherapy with anorexics is a slow and difficult process; about 50 percent of patients continue to have serious psychiatric problems after their weight has stabilized.
Anorexics have been treated with a variety of medications, including antidepressants , antianxiety drugs, selective serotonin reuptake inhibitors, and lithium carbonate. The effectiveness of medications in treatment regimens is as of 2004 debated. However, at least one study of fluoxetine (Prozac) showed it helped the patient maintain weight gained while in the hospital.
A key focus of treatment for anorexia nervosa is teaching the principles of healthy eating and improving disordered eating behaviors. A dietician or nutritionist plays an important role in forming a nutrition plan for the patient; such plans are individualized and ensure that the patient is consuming enough food to gain or maintain weight as needed and stabilize medically. The anorexic's weight and food intake are closely monitored to ensure that the plan is being followed.
Figures for long-term recovery vary from study to study, but reliable estimates are that 40 to 60 percent of anorexics make a good physical and social recovery, and 75 percent gain weight. The long-term mortality rate for anorexia is estimated at around 10 percent, although some studies give a lower figure of 3 to 4 percent. The most frequent causes of death associated with anorexia are starvation, electrolyte imbalance, heart failure, and suicide.
Short of major long-term changes in the larger society, the best strategy for prevention of anorexia is the cultivation of healthy attitudes toward food, weight control, and beauty (or body image) within families. Early treatment such as counseling may help to prevent early signs of disordered eating from progressing into more serious behaviors.
There are many strategies that parents can undertake to help encourage healthy attitudes toward weight, food, and exercise in their children. These include the following:
- teaching children the importance of healthy eating and exercise
- avoiding using food as a punishment or reward
- instilling healthy eating and exercise habits by example
- being a good role model by promoting healthy body image and encouraging children and adolescents to find role models in the media who do the same
- encouraging children or teens who wish to diet to talk to a healthcare professional about healthy strategies to lose weight
Amenorrhea —The absence or abnormal stoppage of menstrual periods.
Binge —A pattern of eating marked by episodes of rapid consumption of large amounts of food; usually food that is high in calories.
Body dysmorphic disorder —A psychiatric disorder marked by preoccupation with an imagined physical defect.
Hyperalimentation —A method of refeeding anorexics by infusing liquid nutrients and electrolytes directly into central veins through a catheter.
Lanugo —A soft, downy body hair that covers a normal fetus beginning in the fifth month and usually shed by the ninth month. Also refers to the fine, soft hair that develops on the chest and arms of anorexic women. Also called vellus hair.
Purging —The use of vomiting, diuretics, or laxatives to clear the stomach and intestines after a binge.
Russell's sign —A scraped or raw area on the patient's knuckles, caused by self-induced vomiting.
Superior mesenteric artery syndrome —A condition in which a person vomits after meals due to blockage of the blood supply to the intestine.
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American Anorexia/Bulimia Association. 418 East 76th St., New York, NY 10021. Telephone: 212/734–1114.
National Association of Anorexia Nervosa and Associated Disorders. Web site: http://www.anad.org.
National Institute of Mental Health Eating Disorders Program. Building 10, Room 3S231. 9000 Rockville Pike, Bethesda, MD 20892. Telephone: 301/496–1891.
Rebecca J. Frey, PhD Stephanie Dionne Sherk