Symptom fluctuation and diagnostic crossover are common in eating disorder patients. A study by Eddy et al. (2008) – who followed patients over an average of 7 years – showed that crossover between subtypes and full-syndrome diagnoses is very common : of those initially diagnosed with anorexia nervosa, almost 73% crossed over to another diagnosis (between symptoms and to bulimia nervosa). More specifically, roughly 50% experienced fluctuation between subtypes (restricting, AN-R, and binge/purge type, AN-BP) and roughly 35% crossed over to bulimia nervosa (a subset experienced both). Of those initially diagnosed with bulimia, roughly 14% crossed over to AN-BP and of those, 3.91% crossed over to AN-R.
This finding (though, well-known to ED specialists and even more well-known to patients) has important implications for treatment. For example, CBT and anti-depressants seem to have positive results in bulimic patients, but not so much in anorexics. What then, about those that crossover from AN-R/AN-BP to BN? Would they, too, benefit from these interventions?
In order to answer those questions, it would be helpful to know who whether we can actually predict who …
I’ve been thinking a lot lately about the eating disorder not otherwise specified (EDNOS) category. ED-NOS is a diagnostic category for all individuals with subthreshold anorexia or bulimia nervosa or those with a mix of symptoms that don’t fit neatly into AN or BN. ED-NOS is essentially everything else. A mixed bag, if you will. It doesn’t tell the clinician nor the researcher anything useful, outside of what it isn’t. So, is there any use for it? If it doesn’t tell the clinician about patient symptoms or guide choice of treatment, why even bother? Does it help researchers understand EDs or do they just want to avoid this messy and heterogenous group (that by the way makes up most of those with eating disorders)? In this entry (and many more to come), I want to further explore these questions.
There’s been a push by researchers to minimize the amount of people who fall into this category. This has namely been done by loosening the criteria for anorexia and bulimia diagnoses for the next edition of the Diagnostic and …
This study is a follow up on the previous study (last entry) which examined the problems with the EDNOS classification, the frequency of transitions between eating disorders and how the DSM should be changed to reflect the clinical reality of eating disorders (and what is the clinical reality?)
In this study, Eddy and colleagues followed 246 women who were initially diagnosed with either AN or BN, for an average of 9 years. The main goal was to study the growing disparity between (1) the consensus that eating disorders are not stable overtime and how (2) the current diagnostic criteria which do not adequately address this, by following the clinical presentation of EDs overtime and providing suggestions for the upcoming DSM-V.
EDNOS is an often ignored category in research – in main part because it is difficult to study such a heterogeneous group. Nonetheless, Eddy et al summarize some interesting findings on diagnostic crossovers and subthreshold EDs:
Eating disorders are rarely static. Symptoms fluctuate, waxing and waning as circumstances change. Often, these fluctuations lead to diagnostic crossover – between subtypes of one disorder or to a different eating disorder altogether. The heterogeneity of symptom severity and frequency led to the establishment of the “eating disorder not otherwise specified” diagnosis in the Diagnostic and Statistical Manual. Essentially, it is everything that doesn’t quite fit into the “anorexia nervosa” or “bulimia nervosa” categories. (For example, I would guess that it is a common diagnosis for patients who fail to meet the “amenorrhea” criterion for the AN diagnosis.)
ED-NOS is a category for everything that doesn’t conform to some rather arbitrary criteria required for bulimia nervosa and anorexia nervosa, meaning: it is the diagnosis for a lot of people. Okay, that’s not very scientific, I know, but I wouldn’t trust these numbers anyway – usually people who fall into this category don’t feel “sick enough” to seek treatment, in the USA they have difficulty getting treatment coverage, and many just don’t think they have a problem (and nor …