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The role of science

Posted Jun 18 2010 1:38pm
This third post in my 2010 ICED Conference series also has to do with Dr. Kelly Vitousek's keynote address (which is also the source for my AN and Competitive Scrabble post). The title of her talk was "Coming Together Without Losing Our Way," and the best succinct summary I can give of her talk was: controversial. Although I don't personally like controversy (can't everyone just play nice and get along?), it can also be useful because it forces people to clarify their thoughts and positions on certain subjects. Dr. Vitousek's talk did that for me.

Much of Dr. Vitousek's talk focused on the difficulties with identifying eating disorders (specifically anorexia) as brain diseases. Her first point was, in my opinion, a fantastic one: what do we mean when we say "brain disease"? Are we all referring to the same thing?

After hearing Dr. Vitousek speak, I can assure you that we're not.

Dr. Vitousek said that there are three main arenas in which people talk about "brain disease" related to anorexia (the commentary underneath each point is quoted from Dr. Vitousek's talk- I can't promise that every word is exactly as she spoke since I was taking notes via typing and not recording, but it's pretty accurate)
1) The acute brain disorder brought on by semi-starvation

However, starvation brain disorder isn't anorexia, and a person can have severe starvation but not AN. It could be that anorexia causes the brain disorder, but semi-starvation itself isn't a brain disorder.

2) The temperamental traits linked to anorexia, but still not anorexia.

Except that traits are not brain diseases, they're not specific to AN, not uniform in AN, and not essential for AN. They are also not all bad, and they're not going away. Some traits may be tweaked or worked around or invested elsewhere. We think that people are "less to blame" if their brains are at fault. (This next is a direct quote that Dr. Vitousek said should be on a bumper sticker). "Traits don't kill people. AN kills people." It's where traits are put that's the most serious problem. Some traits that help keep EDs running can be drafted to work towards recovery. Increasingly experts who study these issues underscore the powerful potential of these traits.

3) It's some variant on a more specific model of AN brain disorder. Hard wired appetitive dysregulation? Anomalous response to starvation? Problems perceiving body size and shape? Cluster of disordered beliefs?

In my own thinking, option #3 seems to make the most sense. Starvation isn't a brain disorder (though it can trigger one if you have the genetic predisposition to anorexia), nor are the temperamental traits linked to anorexia. These traits can be tremendously adaptive, as Dr. Vitousek pointed out. I think these traits can be markers for having a predisposition to anorexia, but that's far from saying "Here's what anorexia is." Frankly, I think the brain disorder called anorexia is a combination of all of the aspects of option #3. My reading of Dr. Walt Kaye's research on interoceptive awareness (and I will talk more about interoceptive awareness from another ICED talk by Bryan Lask) seems to indicate that this could be one of the lynchpin features of anorexia.

After making these three points, Dr. Vitousek began to deconstruct the use and meaning of the word "brain disorder" with respect to anorexia.

[The use of the term] Brain disorder somehow makes patients' suffering is more "respectable" and more sympathetic if symptoms are seen as wholly beyond their control. Neuroimaging has offered some great PR of learning models and psychotherapy. There have been changes in brain scans due to psychotherapy in anxiety disorders. Treatments for EDs can be psychological even when we use a brain disorder model.

What I'm uncertain of is where Dr. Vitousek got the idea that the brain disease model means that psychotherapies for eating disorders are useless. All the evidence shows that they're very much not useless. Secondly, we shouldn't use the term brain disorder because it's less stigmatizing and gives patients that warm fuzzy feeling. I use the term because I think it's the most accurate description for what is actually happening in anorexia nervosa. Is the fact that it helps us waste less time on the Blame Game an advantage? Yep. But that doesn't have any effect on how accurate or true the brain disease model is. Some people respond to the brain disease model with a "screw it" attitude, because if it's biology, then they're well and truly screwed. Is that a disadvantage to the model? Yep. But that's not a problem with the model, it's a problem with how we are interpreting it.

Nor by saying that eating disorders are brain disorders am I trying to erase the influence of environmental factors, both the larger cultural factors at play and the individual life events that work to increase or decrease our risk for developing an eating disorder. Some of us are at higher risk than others for developing an eating disorder, and there is no doubt that environment plays a role. But I also firmly believe that biology is a HUGE predisposing factor to determining our risk for developing an eating disorder.

Dr. Vitousek then went on to critisize science as a tool for learning more about eating disorders--specifically neuroimaging--and how to treat them. I didn't take too many notes on this particular segment because I was too busy personally seething. Neuroimaging is a new field, and it looks a rather lot like a bunch of pretty pictures of brains. The subject is usually covered in the media along the lines of "such-and-such made the brains light up!" Which isn't accurate- our brains (sadly) don't glow. Neuroimaging studies determine the rate at which certain areas of the brain use oxygen, which is a proxy for their metabolic activity. High oxygen use means high metabolic activity means lots of neurons firing. The levels of oxygen use are color-coded, hence the pretty pictures.

Dr. Vitousek rightly pointed out that people are unduly swayed by pretty pictures of brains. Again, this is a problem with how we interpret these studies rather than an inherent problem with the studies themselves. And there are certainly other problems that neuroimaging studies have, such as small sample sizes and the fact that the scans aren't as sensitive as we would like them to be. Much of the time in eating disorder research, however, the neuroimaging studies have simply confirmed what we already suspected, only now we had actual hard data rather than a hunch or information from a few little mousies.

Should we rely solely on neuroimaging studies to teach us more about eating disorders? Nope, and not even Walt Kaye (Dr. Anorexia Neuroimage himself) would say so. Nor is science the only way of learning more about eating disorders. But it does provide the clearest path forward.
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