Eating disorders are characterized by a persistent disturbance of eating patterns that lead to poor physical or psychological health. The major eating disorders are pica, rumination disorder, avoidant/restrictive food intake disorder, anorexia nervosa, bulimia nervosa, and binge-eating disorder.
Eating disorders happen as a result of severe disturbances in eating behavior, such as unhealthy reduction of food intake or extreme overeating. These patterns can be caused by feelings of distress or concern about body shape or weight, and they harm normal body composition and function. A person with an eating disorder may have started out just eating smaller or larger amounts of food than usual, but at some point, the urge to eat less or more spirals out of control.
Eating disorders are very complex, and despite scientific research to understand them, the biological, behavioral, and social underpinnings of these illnesses remain elusive. Eating disorders frequently develop during adolescence or early adulthood, but some reports indicate their onset can occur during childhood or later in adulthood. Many adolescents are able to hide these behaviors from their family for months or years.
Eating disorders are not due to a failure of will or behavior; rather, they are real, treatable medical illnesses in which certain maladaptive patterns of eating take on a life of their own. With anorexia nervosa, individuals starve themselves to be thin, experiencing extreme weight loss. An estimated 0.4 percent of females suffer from anorexia nervosa in a twelve-month period. Bulimia nervosa is binge eating followed by purging (vomiting). An estimated 1 to 1.5 percent of females have bulimia nervosa in a twelve-month period. A third disorder, binge-eating disorder, is characterized by frequent episodes of out-of-control eating. A cycle develops where feelings of shame and disgust caused by obesity, which is brought on by overeating, lead to bingeing again. Community surveys have estimated that 1.6 percent of females and 0.8 percent of males experience binge-eating disorder in a twelve-month period.
Eating disorders frequently occur together with other psychiatric illness such as depression, substance abuse, or anxiety disorders. In addition, people who suffer from eating disorders can experience a wide range of physical health complications, including serious heart conditions and kidney failure, which may lead to death. Recognition of eating disorders as real and treatable diseases is critically important.
Anorexia nervosa is characterized by emaciation, a relentless pursuit of thinness, an unwillingness to maintain a normal or healthy weight, a distortion of body image, an intense fear of gaining weight, a lack of menstruation among girls and women, and extremely disturbed eating behavior. Some people with anorexia lose weight by dieting and exercising excessively; others lose weight by self-induced vomiting or misusing laxatives, diuretics, or enemas. More characteristics of anorexia nervosa include:
Many people with anorexia also have coexisting psychiatric and physical illnesses, including depression, anxiety, obsessive behavior, substance abuse, cardiovascular and neurological complications, and impaired physical development.
Bulimia nervosa is characterized by recurrent and frequent episodes of eating unusually large amounts of food (binge-eating), and feeling a lack of control over the eating. This is followed by some type of behavior that compensates for the binge, such as purging (vomiting, excessive use of laxatives or diuretics), fasting, and/or excessive exercise. Usually, bulimic behavior is done secretly. Additional symptoms include:
Binge-eating disorder is characterized by recurrent binge-eating episodes during which a person feels a loss of control over his or her eating. Unlike bulimia, binge-eating episodes are not followed by purging, excessive exercise, or fasting. As a result, people with binge-eating disorder are often overweight or obese. Characteristics include:
Researchers are unsure of the underlying causes and nature of eating disorders. Unlike a neurological disorder, which generally can be pinpointed to a specific lesion on the brain, an eating disorder likely involves abnormal activity distributed across neural systems. With increased recognition that mental disorders are brain disorders, more researchers are using tools from both modern neuroscience and modern psychology to better understand eating disorders. Additionally, eating disorders appear to run in families so research on genetic factors continues.
Other factors—psychological, interpersonal, and social—can play a role in eating disorders. Psychological factors that can contribute to eating disorders include low self-esteem, feelings of inadequacy or lack of control in life, depression, anxiety, anger, or loneliness.
Interpersonal factors include troubled family and personal relationships, difficulty expressing emotions and feelings, a history of being teased or ridiculed based on size and weight, or a history of physical or sexual abuse. Social factors that can contribute include cultural pressures that glorify thinness and place value on obtaining the "perfect" body, narrow societal definitions of beauty that include only women and men of specific body weights and shapes, or cultural norms that value people on the basis of physical appearance and not inner qualities and strengths.
People with anorexia nervosa see themselves as overweight even though they are dangerously thin. In bulimia nervosa, despite their usually weighing within the normal range for their age and height, sufferers, like individuals with anorexia, may fear gaining weight, desire to lose weight, and feel intensely dissatisfied with their bodies. Many with binge-eating disorders are overweight for their age and height. Feelings of self-disgust and shame associated with this illness can lead to bingeing again, creating a cycle of binge-eating.
Eating disorders can be treated, and a healthy weight can be restored. The sooner these disorders are diagnosed and treated, the better the outcomes are likely to be. Because of their complexity, eating disorders require a comprehensive treatment plan involving medical care and monitoring, professional interventions, nutritional counseling, and, when appropriate, medication management.
Treatment of anorexia calls for a specific program that involves four main phases: restoring the person to a healthy weight lost to severe dieting and purging; treating psychological disturbances such as distortion of body image, low self-esteem, and interpersonal conflicts; reducing or eliminating behaviors or thoughts that lead to disordered eating; and preventing relapse.
Some research suggests that the use of medications, such as antidepressants, antipsychotics, or mood stabilizers, may be modestly effective in treating patients with anorexia by helping to resolve mood and anxiety symptoms that often co-exist with anorexia.
Different forms of psychotherapy, including individual, group, and family-based, can help address the psychological reasons for anorexia nervosa. Some studies suggest that family-based therapies, in which parents assume responsibility for feeding their afflicted adolescent, are the most effective in helping a person with anorexia gain weight and improve eating habits and moods. Others have noted that a combined approach of medical attention and supportive psychotherapy designed specifically for anorexia patients is more effective than psychotherapy alone. The effectiveness of treatment depends on the unique situation of each patient.
Hospital-based care (including inpatient, partial hospitalization, intensive outpatient, and/or residential care in an eating disorders specialty unit or facility) is necessary when an eating disorder has led to physical problems that may be life-threatening or when it is associated with severe psychological or behavioral problems.
The course and outcome of anorexia nervosa vary across individuals; some fully recover after a single episode, some fluctuate between weight gain and relapse, and others chronically deteriorate over many years. The mortality rate among people with anorexia has been estimated at .56 percent per year which is about 12 times higher than the annual death rate due to all causes of death among females ages 15 to 24 in the general population. The most common causes of death are complications of the disorder, such as cardiac arrest, electrolyte imbalance, and suicide.
The primary goal of treatment for bulimia is to reduce or eliminate binge-eating and purging behavior. Nutritional rehabilitation, professional intervention, and medication management are often employed. As with anorexia, treatment for bulimia often involves a combination of options and depends on the needs of the individual.
To reduce or eliminate binge-and-purge behavior, a patient may undergo nutritional counseling and psychotherapy, especially cognitive behavioral therapy (CBT), or be prescribed medication. Some antidepressants, such as fluoxetine (Prozac), can be used to treat eating disorders and may help patients who also have depression and/or anxiety. Medication can also help reduce binge-eating and purging behavior, reduce the chance of relapse, and improve eating attitudes. CBT that has been tailored to treat bulimia has also been shown to be effective in changing bingeing-and-purging behavior and eating attitudes. Therapy may be individually oriented or group-based.
The treatment goals and strategies for binge-eating disorder are similar to those for bulimia. Fluoxetine and other antidepressants may reduce binge-eating episodes and help alleviate depression in some patients. Patients with binge-eating disorder may also be prescribed appetite suppressants. Psychotherapy, especially CBT, in an individual or group environment, is also used to treat the underlying psychological issues associated with binge-eating.
People with eating disorders often do not recognize or admit that they are ill. As a result, they may strongly resist getting and staying in treatment. Family members or other trusted individuals can be helpful in ensuring that the person with an eating disorder receives needed care and rehabilitation.