Researchers from the Swinburne Anorexia Nervosa (SWAN) Research Group have discovered what is believed to be the first biomarker for anorexia nervosa. Biomarkers are typically used in the detection and treatment of physical illnesses, but have never before been used in relation to mental disorders.
Over 70 million people internationally live with eating disorders bout one person dies every hour as a direct result of an eating disorder.
Eating disorders have the highest mortality rate of any mental illness with anorexia being the most deadly mental illness.
One study found that people with anorexia are 56 times more likely to commit suicide than people without an eating disorder.
Research has also found that up to half of the people with an eating disorder are likely to misuse alcohol or illicit drugs at a rate five times higher than the general population.
Due to the effect of eating disorders on the body and mind, treatment options usually include psychological and nutritional counselling and monitoring, according to the National Eating Disorders Association.
“There are various models of treatment for eating disorders,” says Anna Hindell, LCSW-R, a psychotherapist based in New York.
“There are residential programs, hospital programs, day treatment programs. For the majority of people who have eating disorders, and the people I see are high functioning individuals, usually very perfectionistic types, who do well with a mix of psychotherapy, sessions with a nutritionist, and at times, psychopharmacology.”
With eating disorder treatment, 60% of patients make a full recovery. However, only 1 in 10 people with an eating disorder will seek and receive treatment.
Biomarkers are present in an individual regardless of their present state of health.
Therefore it is hoped that with more research, health professionals will be able to use biomarkers as a screening tool to identify those who may be at greater risk of developing anorexia nervosa and thus implement measures to help prevent people developing the condition in the first place.
This research, as outlined below, was published in the Australian & New Zealand Journal of Psychiatry.
The challenges of diagnosis
Anorexia nervosa is a life-threatening eating disorder that generally begins in early adolescence. It is often secretive and associated with persistent denial of symptoms and resistance to treatment. It has the highest mortality rate of all mental illnesses and low rates of recovery. It can be hard to diagnose and even harder to treat.
Mental illnesses are diagnosed with the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) and the International Classification of Diseases. Both methods rely on patients describing symptoms and a clinician's professional expertise. The effects of this condition and the method for diagnosing it actively work against each other. In a condition as time critical as anorexia nervosa, the need for accurate diagnosis and early intervention is key. And that's where biomarkers come in.
What are biomarkers and why are they important?
Biomarkers are characteristics of our bodies that can be measured. They include factors such as blood sugar, heart rate and bone density. They help us detect, screen, prevent and treat physical illnesses, but up until now have not been established for use in clinical practice for any mental illness.
Square Wave Jerks and Anxiety as Distinctive Biomarkers for Anorexia Nervosa
Head of the SWAN Research Group, Dr. Andrea Phillipou, found that a combination of a type of atypical, twitching eye movement, called "square wave jerks," together with anxiety, is a promising two-element biomarker for anorexia nervosa.
Square wave jerks (moving the eyes away and returning them to fixation) were observed in people currently with anorexia nervosa, people who had recovered, and sisters of people with anorexia nervosa. The finding in sisters is critical, because it reveals there is likely a genetic, inherited link.
This discovery of square wave jerks and anxiety as distinctive biomarkers for Anorexia Nervosa it is hoped will revolutionise the screening, detection and diagnosis of the illness.
New and more effective treatments
Biomarkers also tell us about the underlying biological mechanisms involved in an illness.
"Eye movements use very specific brain regions, so when we see these types of atypical eye movements, we have a pretty good idea about which brain areas are not working the way they should," says Dr. Phillipou.
"These areas are also involved in other functions related to anorexia nervosa—such as body image—so it gives us an idea of which brain areas we could target with treatments such as non-invasive brain stimulation."
Prevention over cure
Biomarkers are present regardless of illness state. Think of it as genetic determinism: your body is genetically pre-programmed for various outcomes—some better than others.
"If we're able to do this, we'll be able to implement things to help prevent people developing the condition in the first place."
It's a discovery that has the power to rewrite someone's life story.
Published in the Australian & New Zealand Journal of Psychiatry.