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What Is Anorexia Nervosa, the Most Lethal Mental Illness?

By Natasha Tracy  •   April 30, 2019

Photo Credit: by @CANPharmacyKing
Photo Credit: by @CANPharmacyKing

Do you know the facts around anorexia nervosa? Do you know that anorexia nervosa is considered the deadliest mental illness? Do you know how people are dying of anorexia nervosa? These are extremely important things to understand considering some studies have the rate of anorexia nervosa among women at four percent. That means that up to one in 25 women may suffer from the potentially lethal eating disorder. Read on to learn about what anorexia nervosa is and how treatment can help avoid unfortunate outcomes.

What Is Anorexia Nervosa?

According to Medscape, anorexia nervosa is:

“. . . a potentially life-threatening eating disorder characterized by the inability to maintain a minimally normal weight, a devastating fear of weight gain, relentless dietary habits that prevent weight gain, and a disturbance in the way in which body weight and shape are perceived.”

In the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), anorexia nervosa is considered a feeding and eating disorder, in the same category as bulimia nervosa and binge eating disorder. In order to meet the criteria for the diagnosis of anorexia nervosa, these three criteria must be met:

1. Restriction of energy [food, calorie] intake relative to requirements leading to a significantly low body weight in the context of age, sex, developmental trajectory, and physical health. Significantly low weight is defined as a weight that is less than minimally normal or, for children and adolescents, less than that minimally expected.

2. Intense fear of gaining weight or becoming fat, or persistent behavior that interferes with weight gain, even though at a significantly low weight.

3. Disturbance in the way in which one's body weight or shape is experienced, undue influence of body weight or shape on self-evaluation, or persistent lack of recognition of the seriousness of the current low body weight.

In other words, those with anorexia nervosa restrict their eating, are terrified of gaining weight or becoming overweight and they don’t comprehend the real way their body looks or the impact of their significantly low weight. This is an extremely dangerous combination of symptoms.

Anorexia nervosa is different from other feeding and eating disorders as it solely involves calorie restriction. For example, bulimia nervosa involves both the bingeing (an unhealthy intake of too many calories) and restricting of calories.

Who Gets Anorexia Nervosa?

Anorexia nervosa is predominantly diagnosed in white, adolescent women of middle and upper socioeconomic status. That said, anorexia nervosa is found across all developed countries, ages, races and socioeconomic statuses and in both men and women.

It is much more common in women, thought to be present in 0.3-1.0 percent of all women in the United States with some studies finding it to be as high as 4 percent of women across a lifetime. It is estimated that 0.1-0.3 percent of men suffer from anorexia nervosa.

As noted, anorexia nervosa can occur at any age, but it is estimated that 85 percent of people experience an onset of the illness between the ages of 13-18. People who are younger than 11 or who are older when anorexia nervosa develops have a worse prognosis.

No one factor causes anorexia nervosa. Rather, the illness is caused by a complex combination of biological, psychological and social factors. The following are risk factors for developing anorexia nervosa, although it’s important to understand that one can have one or more of these risk factors and still not develop the disorder:

• Female sex

• Family history of eating disorders

• Perfectionistic personality

• Difficulty communicating negative emotions

• Difficulty resolving conflict

• Low self-esteem

Using studies that involve twins and triplets, it has been estimated that the genetic component of anorexia nervosa is between 50-80 percent. This is similar to bipolar disorder and schizophrenia.

What Makes Anorexia Nervosa So Lethal?

The mortality data for anorexia nervosa shows a higher risk of death in those with anorexia nervosa than in those who smoke heavily. This risk of death is higher than in other eating disorders like binge eating disorder and bulimia nervosa.

It’s a combination of things that makes anorexia nervosa so lethal.

First, those with anorexia nervosa can die of starvation or complications thereof. Starvation typically leads to malnutrition which then leads to a protein deficiency and disruption of many organ systems such as cardiovascular and renal (relating to the kidneys) systems. Any number of complications can result. Some examples of anorexia nervosa complications include:

• Cardiomyopathy (a disease of the heart muscle)

• Hypokalemia (a possibly lethal potassium imbalance)

• Peripheral neuropathy (nerve damage)

• Hair loss

• Thrombocytopenia (low blood platelet count; internal bleeding can occur)

• Infertility

While these types of complications are common with severe cases of anorexia nervosa, less than 10 percent of those with anorexia nervosa actually die of starvation and its complications.

A major cause of death for those with anorexia nervosa is suicide. In fact, death by suicide is more common than death by the complications of starvation. It is estimated that about 31 percent of those with anorexia nervosa suffer from suicidal ideation and more than eight percent actually attempt suicide. The risk of suicide in this group is 10 times higher than in the general population.

Indicators of a higher risk of suicide attempts include:

• Previous suicide attempts

• Physical pain

• Drug use

• Laxative use

And while the risk of suicide is high in all those with anorexia nervosa, it’s even higher in those with comorbid (co-occurring) disorders and unfortunately, such disorders are common. It’s thought that between 33-50 percent of those with anorexia nervosa have a comorbid mood disorder such as depression. Moreover, about 50 percent have a comorbid anxiety disorder.

Those with anorexia nervosa who have a comorbid substance use disorder or a personality disorder (such as borderline personality disorder) are also at particularly high risk of death from suicide and other complications.

Treating Anorexia Nervosa Helps

Treating anorexia nervosa can be difficult due to the symptoms of the illness wherein a person often doesn’t understand the severity and impact of his or her own condition. That said, anorexia nervosa treatment happens every day and it does work.

People with anorexia nervosa are typically treated in the hospital if they have severe medical complications and/or require refeeding, in a psychiatric facility if severely ill yet are medically stable or on an outpatient basis. Typically, a team of people help treat a person with anorexia nervosa. This team includes a psychiatrist to monitor medication, a psychologist for psychotherapy, a nutritionist to help with diet, and other specialists as needed. Individual team makeups vary and jobs of each specialty often overlap.

Psychological therapy treatment is typically the norm. Many therapies have been shown to be useful in treating anorexia nervosa. These include:

• Individual therapy (insight-oriented)

• Cognitive analytic therapy

• Cognitive behavioral therapy (CBT) / Enhanced cognitive behavioral therapy (CBT-E)

• Cognitive remediation therapy (CRT)

• Interpersonal therapy (IPT)

• Motivational enhancement therapy

• Dynamically informed therapies

• Group therapy

• Family-based therapy (FBT)

• Specialist supportive clinical management (SSCM)

• Relatives and caregiver support groups

It’s clear that due to the multitude of psychotherapies that have been shown to work in anorexia nervosa treatment, there is a very good chance there is a therapy or therapies that will suit any individual.

Drugs to Treat Eating Disorders Like Anorexia Nervosa

Drugs are typically used to treat the complications of anorexia nervosa and/or an individual’s comorbid disorders. Additionally, supplements like vitamin D and calcium are typically used to treat and prevent further bone loss. It’s worth noting that medication without therapy, is not nearly as effective for most people. It’s also important to know that treating anorexia nervosa with drugs is typically not indicated until the person has been stabilized with weight restoration.

Two types of medications used to treat anorexia nervosa are antidepressants and atypical antipsychotics.

Antidepressants like the selective serotonin reuptake inhibitor (SSRI) fluoxetine (Prozac) are often useful when the person with anorexia nervosa is also suffering from mood symptoms stemming from depression. Antidepressants may also help stabilize recovery once people have obtained 85 percent or more of their expected weight.

The SSRI antidepressant type is generally preferred over other types of antidepressants but serotonin norepinephrine reuptake inhibitors (SNRIs) may also be useful, particularly if there are concurrent obsessive-compulsive issues.

Another type of medication, atypical antipsychotics, also knowns as neuroleptics, may also be used. This isn’t because people with anorexia nervosa are considered psychotic, this is not the case, it just happens that atypical antipsychotics have been found to be useful in many non-psychotic disorders.

In the case of atypical antipsychotics, low-dose

olanzapine (Zyprexa) may be useful during anorexia nervosa inpatient treatment, especially in the context of anxiety, obsessive eating-related thought patterns and treatment resistance due to failure to engage with treatment.

Prognosis of Anorexia Nervosa

Unfortunately, only about half of all people with anorexia nervosa experience a full recovery. It’s also a fact that many people need multiple attempts at treatment to obtain recovery. However, while some never officially “recover”, with consistent treatment, they go on to live happy and healthy lives, living successfully with the challenge of an eating disorder.


1. Various,

Anorexia Nervosa. Medscape. Updated November 5, 2018.

2. Unknown,

Eating Disorder Statistics. National Association of Anorexia Nervosa and Associated Disorders. Accessed April 15, 2019.


The purpose of the above content is to raise awareness only and does not advocate treatment or diagnosis. This information should not be substituted for your physician's consultation and it should not indicate that use of the drug is safe and suitable for you or your (pet). Seek professional medical advice and treatment if you have any questions or concerns.