As I promised two days ago, here are my thoughts on the other changes made to the DSM. I blogged previously about my thoughts related to the changes made about anorexia nervosa, so now it's onto the other diagnoses.

Bulimia Nervosa

The changes to the BN diagnosis were twofold:

• the frequency of binge eating and purging was decreased from 2x/week for 3 months to 1x/week for three months


• the "non-purging" BN subtype was eliminated, and merged with Binge Eating Disorder

The first criteria is pretty straightforward and there is quite a bit of evidence to indicate that so-called "sub-threshold" bulimia is just as severe as "threshold" bulimia in the DSM-IV (Krug et al, 2008; Wilson and Sysko, 2009). This change isn't anything I have any desire to argue with.

The second criteria is more problematic. The drafters of the ED criteria for DSM-V had this rationale about the change:

DSM-IV requires that sub-type (purging or non-purging) be specified. A literature review indicated that the non-purging subtype had received relatively little attention, and the available data suggested that individuals with this subtype more closely resemble individuals with Binge Eating Disorder. In addition, precisely how to define non-purging inappropriate behaviors (e.g., fasting or excessive exercise) is unclear.

Deletion of this subtype is recommended. This also requires rewording of Criterion B.

Criterion B specifies "inappropriate compensatory behaviors," and these behaviors would be limited to self-induced vomiting, and misuse of laxatives and/or diuretics. To some extent, I see the difficulties in defining fasting or excessive exercise- it isn't clear. But my next question would be then to define the "misuse" of laxatives and diuretics. So if you binge and then you can't take a crap and you swallow a few pills, is that misuse? What if the box says take two to four pills, and you always take four because you're convinced that any less wouldn't get the food out. Is that misuse? You're following the directions on the box, after all. If they specified "use" of laxatives and diuretics to specifically try and "undo" a binge, then I wouldn't probably be so prickly. It's clear that it's a purging behavior. But misuse? If the idea is to get rid of unclear definitions, I'm not entirely sure they did that.

My other question is this: I thought fasting and exercise were kind of considered forms of purging. I'm not sure what the distinction is--does purging have to involve your mouth or your butt? Sorry to be kind of crass, but I'm still trying to figure that one out. It's one thing to remove the subtypes and just create a "bulimia nervosa" definition that encompasses both purging and non-purging types, but I'm not positive on the wisdom of removing fasting and excessive exercise from the BN criteria.

The DSM-V draft criteria cited a study titled "The Validity and Utility of Subtyping Bulimia Nervosa," which came to the following conclusions:

Another possible reason for the lack of data on individuals with BN-NP may be a problem in diagnosing these subjects. Individuals who would qualify for the diagnosis BN-NP may go unnoticed or be wrongly diagnosed as BED or ED-NOS as a result of incomplete assessment of nonpurging compensatory behaviors. Both dieting and exercising are common in the general population, and are not necessarily pathological. There is no clear criterion to decide at what point the amount of exercising and dieting exceeds a cut-off point and becomes abnormal. This does not mean that nonpurging compensatory behaviors are clinically irrelevant. A number of studies have provided information that both purging and nonpurging compensatory behaviors are important clinical markers, for example, they both have high rates of comorbidity; their frequency is associated with severe maladaptive core beliefs and they are associated with impaired social functioning. The lack of clear definitions of nonpurging compensatory behaviors combined with their clinical relevance highlights the need for better diagnostic criteria.

Although the number of subjects with BN-NP [non-purging bulimia nervosa] is generally lower than that of BN-P [purging bulimia] and BED, in some studies the rates are comparable to, or in favor of, BN-NP, notably for three of the five general population studies. This may be a result of the more standard use of (semi-) structured diagnostic interviews in this type of study, in which the presence of nonpurging compensatory behaviors is routinely checked. Again, this calls for increased attention to the formulation of clear and easy to apply diagnostic criteria for nonpurging compensatory behaviors.

The study called for one of three possible solutions to this subtyping issue:

1. Maintain the current situation by keeping BN-NP as a subtype separate from BN-P as in DSM-IV, that is, a distinction between purging and nonpurging types of compensatory behavior in people who binge eat.


2. Eliminate nonpurging compensatory behavior as a diagnostic criterion. Individuals
   receiving a diagnosis of BN-NP in DSM-IV would be designated as having BED.


3. Inclusion of BN-NP in a broad BN category, as suggested by Walsh and Sysko, where a combination of binge eating with only nonpurging forms of compensatory behavior would be considered an atypical form. This would require a clear definition of the normal/abnormal boundaries of food restriction and exercising.

Obviously, the decision was made in favor of option 2.

How the specific vagaries of diagnosis will affect treatment remains to be seen. The irony is that most treatments for BED recommend physical activity--which is fine, but not for someone who uses exercise as a compensatory behavior. The debate isn't settled, and I'm not sure what I would do myself if I got to have the DSM Magic Wand.

Binge Eating Disorder

Binge eating disorder was included, which was a HUGE victory (no pun intended). BED is been fairly well defined for quite some time, and there are specific treatments that can help people struggling with binge eating.

The frequency of binge eating was specified at 1x/week for three months to make it more in line with the BN diagnosis. This seemingly low threshold for binge frequency has gotten some people up in arms. Writes psychiatrist Allen Frances in an article titled "Opening Pandora's Box":

Binge Eating Disorder will have a rate in the general population (estimated at 6%) and this will probably become much higher when the diagnosis becomes popular and is made in primary care settings. The tens of millions of people who binge eat once a week for 3 months would suddenly have a “mental disorder”― subjecting them to stigma and medications with unproven efficacy.

This is certainly a valid concern (a diagnosis should adequately capture all people who are ill with a disorder and none of those who aren't), but just because a diagnosis is more common doesn't mean it's not real. Also, the problems with people being subjected to medication seems more of a problem with our messed-up health care system and non-specialists making rather specialized diagnoses (I wouldn't want my cardiologist trying to diagnose my foot problem) than with the actual diagnostic criteria.

If the criteria for BED was just one binge a week for three months, I'd be much more willing to concede Dr. Frances' point. However, there are other criteria for BED that include feeling overly guilty or disgusted with oneself; the feeling of not being able to stop eating; feeling depressed afterwards; etc. Occasional overeating is unlikely to happen alone and result in "marked distress."

Still, Frances' overall argument is interesting and timely and well worth reading.

Purging Disorder

Rachel at The F Word pointed out the lack of formal inclusion of purging disorder in the DSM-V by highlighting this paragraph from the EDNOS section:

The work group is considering whether it may be useful and appropriate to describe other eating problems (such as purging disorder–recurrent purging in the absence of binge eating, and night eating syndrome) as conditions that may be the focus of clinical attention. Measures of severity would be required, and these conditions might be listed in an Appendix of DSM-5. If these recommendations are accepted, the examples in Eating Disorder Not Otherwise Specified will be changed accordingly.

I'm not surprised that purging disorder didn't make it in as a stand-alone diagnosis, not because the data isn't good--it is--but that it's rather new. Rachel has a whole post devoted to purging disorder that is well worth reading, and you can find more studies on purging disorder here.

For most people, anorexia nervosa and binge eating seem pretty much as opposite as you can get: one involves extreme food denial, and one involves extreme food consumption. There also appear to be preexisting biochemical differences between the two disorders. On the other hand, all types of eating disorders show a correlation with mood and anxiety disorders, and tend to overlap with numerous addictive disorders as well.

Several years ago, Christopher Fairburn proposed a transdiagnostic model of eating disorders, which essentially states that in EDs "shared, but distinctive, clinical features tend to be maintained by similar psychopathological processes" that include low self-esteem, interpersonal difficulties, mood intolerance, and perfectionism. Supporting this theory is the high degree of "switching" from one ED to another, a process formally known as diagnostic migration.

Yet the issue remains: how can two disorders that appear to be almost (ahem) mirror images of each other be the same and yet be different?

In a recent article titled "Affect, cognition, awareness and behavior in eating disorders. Comparison between obesity and anorexia nervosa," a Hungarian psychiatrist looked at differences between AN and obesity. Now, obesity isn't a mental health disorder, nor should it be one; however, binge eating disorder is very real. Since the original text is in Hungarian (with only an English abstract), I don't know whether this is a translation mistake or whether the author is trying to assert that obesity is a mental illness. For the sake of MY arguments and thinking, however, I'm going to think of "obesity" in this article as BED since this appears what the author really should be getting at.

Cserjési makes a cogent point in the abstract:

"Previous studies suggested that emotional disturbances (depression, anxiety and alexithymia), cognitive impairments and distortion of body image are frequently associated with anorexia nervosa. However, obesity is mostly regarded as a weight management problem."

Which is quite true. Although many still view anorexia as a choice and a diet gone too far, there is a slow shift to seeing it as a real mental illness. BED is sadly even further behind.

The results of this study, however, are far more intruiging.

Neuropsychological tasks showed common deficit in attention capacity. Obese patients, both children and adult showed impaired shifting capacity and mental rigidity associated with frontal lobe based executive functions. Obese patients had difficulty in categorizing negative emotions (sadness), anorexic patients in treating happy faces. Obese group evaluated positively the overweight body on the implicit level. Anorexic group did not evaluate positively the ultra thin body. Conclusion: our results suggest that restrictive anorexia nervosa has several common features with anxiety disorder, while obesity can be associated most probably with addictive pathologies.

Impaired set shifting (also called cognitive inflexibility) is now being considered as one of the trademarks of anorexia, as is the relationship between anorexia and anxiety disorders, especially OCD. And Nora Volkow's work out of the National Institute on Drug Abuse has been examining the similarities between obesity, compulsive or binge eating and addiction. (h/t Tiptoe for the last link)

This hasn't totally resolved the issue, as there is plenty of evidence that anorexia shares similarities with addiction and that anxiety is a problem in binge eating. But examining these disorders for their similarities and differences not just in behavior but in underlying neuropsychology will hopefully tell us more about what is really going on and what really causes eating disorders.

I've read a fair bit on the history of anorexia, of the fasting saints of the Middle Ages, of the initial medical reports in the 1600s, followed by the formal medical diagnoses in the mid-1800s. Clearly, anorexia is not a new disease.

The history of bulimia and binge eating disorder, however, is much fuzzier. There were the Roman vomitoriums, yes, but otherwise the history is vague until about the 1900s.

However, a new article in New Scientist writes about a famous composer who likely suffered from binge eating disorder (and also lead poisoning). Could Handel's suffering have helped inspire his great works, such as The Messiah, the article asks?

The year 1737 marked a turning point for England's most celebrated composer. George Frideric Handel had been entertaining London society with his Italian operas since 1720. Each season he staged several, for which he wrote the music, hired the singers and directed 50 or more performances. Then he abandoned opera and wrote the type of music he is best remembered for, his English oratorios. Handel's operas had been peopled by gods and heroes, played by strutting superstar singers. Now his themes tended towards the tragic, his characters mere mortals and his music more personal. What prompted the change? Ill health, says Handel authority David Hunter.

Handel's contemporaries were well aware of his binges, and they were not afraid to ridicule his food intake or his weight.

Handel was clearly obese. According to friends and admirers he "paid more attention to [his food] than is becoming in any man" and was "corpulent and unwieldy in his motions". Others were less kind, making him the butt of jokes and mocking verses. "He consumed what even by the standards of his well-fed peers were embarrassingly large amounts of food and drink," says Hunter. His odd behaviour indicates something other than simple greed: Handel couldn't control his eating, even if it meant losing friends or facing ridicule.

One secret binge caused a rift between Handel and one of his oldest friends, the painter Joseph Goupy. In 1744 or 1745, Handel invited Goupy home for dinner, warning him that business wasn't going too well so the meal would be frugal. Dinner over, Handel excused himself. He was gone so long, Goupy went looking for him - and found Handel stuffing himself with "such delicacies as he had lamented his ability to afford his friend". Furious, Goupy left, and had soon produced a new portrait of Handel, one in which he was caricatured as an organ-playing pig (above).

This loss of control over eating certainly characterizes binge eating disorder, and Hunter tentatively diagnosis the great composer with BED, though he speculates Handel may also have been suffering from other conditions, such as lead poisoning and heavy drinking. But even in the 1700s, without the thin-is-in culture, fat and overeating were derided.

Certainly Handel's diagnoses, whatever they may be, do not detract from his music. I've sung parts of the Messiah in various choirs, and it's a lovely piece of music. But I never knew that Handel might have struggled with some of the same demons that I did, which makes it all the more poignant.

Image courtesy New Scientist.

Foods, especially sweet ones, activate the pleasure center in your brain. It makes sense for such a primal need (fuel) to be associated with pleasure. Think of it as insurance for the species: pleasure is the motivation to pursue food so you don't die.

Walt Kaye did research looking at how sugar water activated these pleasure regions in women who have recovered from anorexia. Compared to normal controls, recovered anorexics showed a blunted pleasure response to sugar water. This gives some insight on how people with AN can ignore the drive to eat- it's just not as pleasurable.

The assumption for people who are considered "overweight" or obese is that eating is extremely pleasurable, so they do it more. Aside from the assumption that overweight people intrinsically eat more than thinner people, what the found was the complete opposite. Compared to their leaner counterparts, obese women showed a lower pleasure response when they tasted a milkshake.

Says an AP story about the study:

Eating can temporarily boost dopamine levels. Previous brain scans have suggested that the obese have fewer dopamine receptors in their brains than lean people. And a particular gene version, called Taq1A1, is linked to fewer dopamine receptors...

...Brain scanning showed that a key region called the dorsal striatum — a dopamine-rich pleasure center — became active when they tasted the milkshake, but not when they tasted the comparison liquid that just mimicked saliva.

Yet that brain region was far less active in overweight people than in lean people, and in those who carry that A1 gene variant, the researchers reported. Moreover, women with that gene version were more likely to gain weight over the coming year.

Some of the other comments by the researchers were just smashingly ridiculous (such as "don't condition your brain to eat lots of Ho-Ho's"), but I think the study raises many poignant questions for people with eating disorders.

I think this study should be repeated in people who binge eat, whether they have BED or bulimia, because this could likely be eye-opening to what actually goes on inside the brain. And perhaps this blunted pleasure response to food could be part of what links anorexia to bulimia. However, says Volkow, dopamine "is not just about pleasure." Dopamine is a regulatory hormone, conditioning and training the brain, as well as helping in impulse control. Just as serotonin's functions go deeper than mood, so does dopamine's role extend far beyond pleasure.

This research forms one more piece of the puzzle, one more factor that explains why and how eating disorders start and how the brain keeps them going.

Several interesting notes:

Eric Stice, the lead researcher on the current paper, also helped with Walt Kaye's study on taste response in recovered anorexics

The different headlines from this same paper:

Brain's reaction to yummy food may predict weight (AP)
Milkshake study reveals brain's role in obesity (Reuters)
Obesity caused by deficit of brain 'pleasure centers': study (AFP)

Nice leap on the last one there, folks. Yikes. The editor who let that one pass really ought to be flogged.