Anorexia nervosa Health Article

Definition

Anorexia nervosa (AN) is an eating disorder characterized by an intense fear of gaining weight and becoming fat. Because of this fear, the affected individual starves herself or himself, and the person's weight falls to about 85% (or less) of the normal weight for age and height.

Description

AN affects females more commonly than males—90% of those affected are female. Typically, the disorder begins when an adolescent or young woman of normal or slightly overweight stature decides to diet. As weight falls, the intensity and obsession with dieting increases. Affected individuals may also increase physical exertion or exercise as weight decreases to lose more pounds. An affected person develops peculiar rules concerning exercise and eating. Weight loss and avoidance of food is equated in these patients with a sense of accomplishment and success. Weight gain is viewed as a sign of weakness (succumbing to eat food) and as failure. Eventually, the affected person becomes increasingly focused on losing weight and devotes most efforts to dieting and exercise.

Anorexia nervosa is a complex eating disorder that has biological, psychological, and social consequences for those who suffer from it. When diagnosed early, the prognosis for AN is good.

Causes

The exact causes of AN are not currently known, but the current thinking about AN is that it is caused by multiple factors. There are several models that can identify risk factors and psychological conditions that predispose people to develop AN. The predisposing risk factors include:

• female gender
• perfectionism
• personality factors, including being eager to please other people and high expectations for oneself
• family history of eating disorders
• living in an industrialized society
• difficulty communicating negative emotions such as anger or fear
• difficulty resolving problems or conflict
• low self-esteem

Specialists in family therapy have demonstrated that dysfunctional family relationships and impaired family interaction can contribute to the development of AN. Mothers of persons with AN tend to be intrusive, perfectionistic, overprotective, and have a fear of separation. Fathers of AN-affected individuals are often described as passive, withdrawn, moody, emotionally constricted, obsessional, and ineffective. Sociocultural factors include the messages given by society and the culture about women's roles and the thinness ideal for women's bodies. Developmental causes can include adolescent "acting out" or fear of adulthood transition. In addition, there appears to be a genetic correlation since AN occurs more commonly in biological relatives of persons who have this disorder.

Precipitating factors are often related to the developmental transitions common in adolescence. The onset of menarche (first menstrual cycle) may be threatening in that it represents maturation or growing up. During this time in development, females gain weight as part of the developmental process, and this gain may cause a decrease in self-esteem. Development of AN could be a way that the adolescent retreats back to childhood so as not to be burdened by maturity and physical concerns. Autonomy and independence struggles during adolescence may be acted out by developing AN. Some adolescents may develop AN because of their ambivalence about adulthood or because of loneliness, isolation, and abandonment they feel.

Symptoms

Most of the physical symptoms associated with AN are secondary to starvation. The brain is affected— there is evidence to suggest alterations in brain size, neurotransmitter balance, and hormonal secretion signals originating from the brain. Neurotransmitters are the chemicals in the brain that transmit messages from nerve cell to nerve cell. Hormonal secretion signals modulate sex organ activity. Thus, when these signals are not functioning properly, the sex organs are affected. Significant weight loss (and loss in body fat, in particular) inhibits the production of estrogen, which is necessary for menstruation. AN patients experience a loss of menstrual periods, known as amenorrhea. Additionally, other physiologic systems are affected by the starvation. AN patients often suffer from electrolyte (sodium and potassium ion) imbalance and blood cell abnormalities affecting both white and red blood cells. Heart function is also compromised and a person affected with AN may develop congestive heart failure (a chronic weakening of the heart due to work overload), slow heart rate (bradycardia), and abnormal rates and rhythms (arrhythmias). The gastrointestinal tract is also affected, and a person with AN usually exhibits diminished gastric motility (movement) and delayed gastric emptying. These abnormalities may cause symptoms of bloating and constipation. In addition, bone growth is affected by starvation, and over the long term, AN patients can develop osteoporosis, a bone loss disease.

Physically, people with AN can exhibit cold hands and feet, dry skin, hair loss, headaches, fainting, dizziness, and lethargy (loss of energy). Individuals with AN may also develop lanugo (a fine downy hair normally seen in infants) on the face or back. Psychologically, these people may have an inability to concentrate, due to the problems with cognitive functioning caused by starvation. Additionally, they may be irritable, depressed, and socially withdrawn, and they obsessively avoid food. People affected with AN may also suffer from lowered body temperature (hypothermia), and lowered blood pressure, heart rate, glucose and white blood cells (cells that help fight against infection). They may also have a loss of muscle mass.

In order to diagnose AN, a patient's symptoms must meet the symptom criteria established in the professional's handbook, the Diagnostic and Statistical Manual of Mental Disorders, also called the DSM. These symptoms include:

• Refusal to maintain normal body weight, resulting in a weight that is less than 85% of the expected weight.
• Even though the affected person is underweight, he or she has an intense fear of gaining weight.
• Distorted body image, obsession with body weight as key factor in self-evaluation, or denial of the seriousness of the low body weight.
• Amenorrhea.