Last week, I blogged about a study that examined personality traits and clinical variables associated with excessive exercise in eating disorder patients. In that study, 2 out of 5 participants engaged in excessive exercise. Today, I’m going to discuss a study that suggests over-exercise in disordered eating patients is associated with suicide behaviour.
Suicide rates in eating disorder patients are high. One meta-analysis suggested that out of all eating disorder related deaths, 1 in 5 are suicides. (Keep in mind, these numbers are really hard to pin down as they depend a lot on the sample population, sample size, and how the authors did their statistics, among other things.)
Another analysis found that the standardized mortality ratio (ratio of observed deaths in the study sample/expected deaths in the population of the same age but without the disease/disorder you are studying) for suicide in eating disorders was 31 for patients with anorexia nervosa and 7.5 for patients with bulimia nervosa. Moreover, around 25-35% of bulimia nervosa and 3-20% of anorexia nervosa patients attempt suicide at least once in their lifetime …
Eating disorder not otherwise specified (EDNOS), the catch-all diagnosis for eating disorder patients that don’t neatly fit into the DSM-IV anorexia nervosa (AN) or bulimia nervosa (BN) categories, is often thought to be less severe. Patients with sub-threshold AN or BN (missing one or two criteria) fall into the EDNOS (a large proportion, perhaps the majority, of patients). The inherent assumption in the word sub-threshold is that the patient is not as sick. Symptom frequency and behaviours are not that bad.
Increasingly, research is showing otherwise (which comes as no surprise for those of us who have struggled with eating disorders).
One study that has illustrated this quite nicely was published in 2009 by Dr. Scott Crow and colleagues in the American Journal of Psychiatry (freely available online here). Given that most ED mortality research has focused on anorexia nervosa, Crow et al wanted to compare mortality (from all-causes and suicide specifically) in patients with anorexia nervosa as well as bulimia nervosa and EDNOS. Furthermore, they were interested in studying a heterogenous sample over an extended period, …
You often hear that anorexia nervosa has the highest mortality rate of any psychiatric illness, but you might struggle to find the rates for bulimia nervosa or EDNOS. Even for AN, the most common cause of death is rarely reported and the reported rates often vary a lot (depending on the study (and the media outlet).
I wanted to find out what are: (1) the mortality rates in BN and EDNOS and (2) the common causes of death in these disorders. A relatively recent meta-analysis (click here for some background, pros and cons of meta-analyses) of 36 studies, which addressed some of my questions, was published by Arcelus and colleagues.
They excluded studies that had less than 15 patients and/or <1-year follow-up.
So, what did they find?
Mortality in Anorexia Nervosa: