What is anorexia nervosa?
Anorexia nervosa is a serious and potentially life-threatening mental illness. Anorexia nervosa is an eating disorder defined by an inability to maintain one’s body weight within 15 percent of their Ideal Body Weight (IBW). Other essential features of this disorder include an intense fear of gaining weight, a distorted image of one’s body, denial of the seriousness of the illness, and—in females—amenorrhea, an absence of at least three consecutive menstrual cycles when they are otherwise expected to occur.
There is no specific test than can diagnose this complex illness. Rather, a diagnosis of anorexia nervosa is made when a physician or a mental health professional recognizes the signs, symptoms and patterns of thinking and behavior that characterize this illness. It should be further noted that a number of common medical illnesses can cause symptoms that are similar to those seen in anorexia nervosa. Therefore it should be stressed that prior to a diagnosis of anorexia nervosa being made, a person should have a complete medical evaluation to rule out common illnesses with similar symptoms (thyroid disease, inflammatory bowel disease, etc.).
Who develops anorexia nervosa?
Like all eating disorders, anorexia nervosa tends to occur in adolescence, but can develop at any time throughout one’s lifetime. It predominately affects adolescent girls and young adult women, although it also occurs in boys, men, older women and younger girls. Others especially at risk for eating disorders include athletes, dancers and models for which thinness has become a “professional requirement.”
Many people with anorexia nervosa are also diagnosed with other psychiatric illnesses including depression, anxiety and substance abuse disorders. It has also been suggested that the presence of depression and anxiety disorders may increase the risk of developing anorexia nervosa later in life.
Slightly less than one percent of females will be diagnosed with the illness throughout the course of their lives. Historically, anorexia nervosa was thought to be most common in upper-middle class Caucasian females. Over the past few decades, it is clear that women of all ethnicities and socioeconomic backgrounds are confronted with the challenges of anorexia nervosa. Males are significantly less likely to have anorexia nervosa, but it has been suggested that as awareness grows, more males are being treated for this severe mental illness.
What are the common signs of anorexia nervosa?
The main symptoms of Anorexia Nervosa are a preoccupation with food and an inability to maintain normal body weight. One of the most frightening aspects of the disorder is that people with anorexia nervosa continue to think they “look fat” even when have become dangerously thin. Individuals with anorexia nervosa may develop odd and ritualistic eating habits such as cutting their food into tiny pieces, refusing to eat in front of others or fixing elaborate meals for others that they themselves don't eat. Food and weight become obsessions as people with this disorder constantly think about their next encounter with food.
In addition to decreasing their food and liquid intake, people with anorexia nervosa will often exercise excessively as another means of weight loss. They might also try increasing caffeine intake (to increase urination and water loss) or abusing laxatives as other means of weight loss.
As people become thinner, their body starts to experience physical changes associated with malnutrition and starvation. Their nails and hair become brittle, their skin may become dry and yellow and they may grow fine hair (called lanugo) on parts of their body previously without hair. People with anorexia nervosa often complain of feeling cold as their body loses the ability to maintain its temperature. They may also report feeling tired, without energy, or unable to focus both due to their malnutrition and to the hormonal (e.g., thyroid) changes that may occur.
The starvation experienced by persons with anorexia nervosa can cause damage to vital organs such as the heart, kidneys and brain. Pulse rate and blood pressure drop, and people suffering from this illness may experience irregular heart rhythms or heart failure which can lead to death in certain situations. Nutritional deprivation along with purging behaviors causes electrolyte abnormalities such as low potassium and low sodium. Nutritional deprivation also leads to calcium loss from bones, which can become brittle and prone to breakage (e.g., osteoporosis). Nutritional deprivation also leads to decreased brain volume which can cause changes in a person’s thinking. In the worst-case scenario, people with anorexia can actually starve themselves to death. Anorexia nervosa has the highest mortality rate of any psychiatric illness, both due to the complications of malnutrition and the high rate of suicide in this population.
What are the causes of anorexia nervosa?
Scientists have studied the role of genetics, environment and biochemistry of people with anorexia nervosa. Although its precise cause remains unknown, scientists agree that it is caused by a combination of genetic and environmental factors. Eating disorders tend to run in families, with female relatives most commonly affected. Close relatives of a person with anorexia nervosa are more than 10 times more likely to have an eating disorder themselves than someone without this illness in their family. Scientific studies have shown that certain chemicals in the brain, specifically the neurotransmitters norepinephrine and serotonin, are not functioning optimally in patients with anorexia nervosa, something which can worsen in times of malnutrition and starvation.
Behavioral and environmental influences also play a role in vulnerability to the illness and stressful life events have been found to increase the risk of developing anorexia nervosa. This has been shown from a scientific standpoint: the hormones controlling the body’s response to stressful events, specifically cortisol and vasopressin, have been shown to be dysfunctional in people with anorexia nervosa.
What treatments are available for anorexia nervosa?
Recovery from anorexia nervosa is possible. In long term studies of people with this illness, about one-half fully recover, many have intermittent periods of recovery and relapse, and a small percentage continue to experience a more chronic form of anorexia nervosa with ongoing symptoms of this and other eating disorders. It is still unknown exactly how to predict who will have a short-lived course of this illness and for whom it will be a more chronic and debilitating illness.
Fortunately, most of the complications experienced by persons with anorexia nervosa are reversible when they restore their weight through engagement in treatment. People with this disorder should be diagnosed and treated as soon as possible because eating disorders are most successfully treated when diagnosed early. Some patients can be treated as outpatients, but others may need medical hospitalization to stabilize their dangerously low weight through “re-feeding” treatment. This may include the use of feeding tubes, intravenous fluids, and structured diets with supervised meals. Weight gain is usually gradual: one to three pounds per week is considered safe and desirable. Given the large overlap between medical and psychiatric symptoms of anorexia nervosa, coordination of care between different medical and mental health professionals is of upmost importance.
A variety of psychotherapeutic approaches are used to help people with anorexia nervosa. Individual therapy is a standard treatment for this illness. Dialectical behavioral therapy (DBT) can help to teach coping skills and cognitive behavioral therapy (CBT) can be used to change unhealthy thoughts and behaviors. Group therapy is often advised to create a safe environment where people can share their experiences with others. Family therapy is important—particularly if the individual is living at home and is a child or young adolescent—and is specifically useful in mobilizing family support for this complex illness.
Unfortunately there is no medication that can cure anorexia nervosa. In fact, many psychiatric medications have been studied and have been found to be unhelpful in the treatment of this complex illness. In general, certain psychiatric medications may be useful in treating isolated symptoms of anorexia nervosa, but this is beyond the scope of this review and should be discussed at length with one’s treating physicians. While not indicated for anorexia nervosa itself, medication treatment of coexisting anxiety, depression, and other mental illnesses can very helpful for people with anorexia nervosa.
Families and friends can be most helpful in encouraging their loved ones to seek treatment for this complex mental illness. With coordinated treatment and the support of family and friends, most people with Anorexia Nervosa can expect to see a decrease in their symptoms as they go on to live meaningful lives.
Reviewed by Ken Duckworth, M.D., and Jacob L. Freedman, M.D., January 2013