FactCheck Q A: do eating disorders have the highest mortality rate of all mental illnesses?

The Conversation is fact-checking claims made on Q&A, broadcast Mondays on the ABC at 9:35pm. Thank you to everyone who sent us quotes for checking via Twitter using hashtags #FactCheck and #QandA, on Facebook or by email.

At the less serious end, in terms of loss of self-esteem and self-confidence, but more serious end, poor diet and so on, and at the very serious end, eating disorders, which are the mental illness type which has the highest mortality rate. – Shadow Minister for Climate Change and Energy, Mark Butler, speaking on Q&A, October 3, 2016.

Shadow Minister for Climate Change and Energy, Mark Butler, told Q&A that “eating disorders … are the mental illness type which has the highest mortality rate”.

Is that true?

Checking the source

When asked to provide sources to support his statement, a spokesperson for Mark Butler pointed The Conversation to the National Eating Disorders Collaboration website, which says:

The mortality rate for people with eating disorders is the highest of all psychiatric illnesses and over 12 times that seen in people without eating disorders.

The National Eating Disorders Collaboration is linked to the federal Department of Health, and brings together people and organisations with an expertise and/or interest in eating disorders. So it is quite a reliable source.

However, we can also test his statement against publicly available research.

Do eating disorders have the highest mortality rate of all mental illness types?

Many studies, meta-reviews and meta-analyses reveal the high mortality rates for eating disorders, in particular anorexia nervosa. (Meta-analyses and meta-reviews involve researchers reading and compiling the results from many studies and use complex statistics to identify bigger trends).

Is it the highest? It depends a bit on what you mean by “mental illness type”. It’s definitely among the highest.

The most recent meta-review published in 2014 found that while the mortality ratio for eating disorders is higher than for most other psychiatric disorders, some substance use disorders had higher mortality ratios.

The Diagnostic and Statistical Manual of Mental Disorders (DSM) published by the American Psychiatric Association and used internationally to classify and diagnose mental disorders, defines substance use disorders as psychiatric condition. It defines eating disorders as:

… characterised by a persistent disturbance of eating or eating-related behaviour that results in the altered consumption or absorption of food and that significantly impairs physical health or psychosocial functioning.

Eating disorders defined in the DSM-5 include anorexia nervosa, bulimia nervosa and binge-eating disorder, amongothers. Eating disorders affect men and women of all ages, with the highest incidence among girls and women. Many cases emerge in adolescence.

It’s worth noting that there are some overlaps between eating disorders and substance use disorders as well as anxiety and depression. It’s not always clear what caused what, or what the cause of death was because a person may have many physical and psychological conditions.

What does the research show?

A report written by Deloitte Access Economics for the Butterfly Foundation estimated that there were 913,986 people in Australia with eating disorders in 2012. That’s 4% of the population. The report estimated that 1,829 people died from eating disorders in Australia in 2012.

A number of international reviews and meta-analyses comparing mortality rates of psychiatric disorders show that substance use disorders and eating disorders have the highest risk of death.

The most recent meta-review, published in 2014, summarised data and findings from research of over 1.7 million patients. The authors estimated (in Table 1 of the study here) that the mortality risk is higher for opioid use, cocaine use, and amphetamine use than for anorexia nervosa. The authors said that:

All disorders had an increased risk of all-cause mortality compared with the general population, and many had mortality risks larger than or comparable to heavy smoking. Those with the highest all-cause mortality ratios were substance use disorders and anorexia nervosa.

A systematic review published by British researchers in 1998 compared the mortality rates of 27 mental disorders. It also found that eating disorders had among the highest risks of premature death among both genders, but prescription and legal drug abuse, opioid abuse were higher in some analyses.

A meta-analysis of mortality rates in eating disorders published in 2011 reported that anorexia nervosa had a significantly higher mortality ratio than schizophrenia and bipolar disorder.

A 1995 meta-analysis of 42 studies of eating disorder case reports noted that:

The aggregate annual mortality rate associated with anorexia nervosa is more than 12 times higher than the annual death rate due to all causes of death for females 15-24 years old in the general population (0.00045 deaths per year) and more than 200 times greater than the suicide rate in the general population (0.00002 suicides per year).

What are people with eating disorders dying from?

Deaths associated with eating disorders are typically caused by medical complications (such as cardiovascular issues and multiple organ failure), suicide or complications relating to substance use.

A United States study reported on the causes of death in a group of eating disorder patients between 1979 and 1997. Of the 52 deceased patients, 20 died from medical causes, 13 died from suicide, 10 died from causes related to substance use, and nine died from “traumatic causes” (which was not further defined in that study). Examples of deaths from medical causes include acute alcohol intoxication, cardiorespiratory issues, issues with the liver and other major organs, and pneumonia.

Although high rates of mortality are reported for eating disorder patients, there are a large proportion of people with these conditions who go on to engage in successful treatment, and recover. Inpatient or outpatient treatment usually involves a combination of nutritional management, psychotherapy, and medication.

Verdict

Mark Butler was broadly correct. Many studies show that eating disorders are among the mental illness types with the highest mortality rate.

Is it the highest? It’s hard to say for sure. Twostudies that compile much of the research in this area confirm that substance use disorders and eating disorders have the highest mortality risk of all psychiatric conditions.

Some patients may experience more than one psychiatric disorder. It’s not always clear what role an eating disorder may have had in a person’s death, as there may be many influencing factors.

So it is hard to make a clear statement about which psychiatric conditions have the highest mortality rate of all. – Zali Yager.

Review

This is a sound analysis. It is worth noting that all eating disorders are associated with elevated mortality and suicide, as sometimes the general public fixate on anorexia nervosa. – Tracey Wade.

If this article has raised concerns about eating disorders, please contact the Butterfly Foundation national hotline on 1800 33 4673; or visit their website for support and resources for eating disorder sufferers and their families and carers.

If this article has raised issues for you or if you’re concerned about someone you know, call Lifeline on 13 11 44.

Zali Yager receives funding from the Australian Research Council, Australian Anti-Doping Association, and Oregon Health and Science University. She is a member of the Academy for Eating Disorders and has previously collaborated with the Butterfly Foundation on research projects.

Tracey Wade does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond the academic appointment above.