"The effects of undernutrition..."
One of the most profound things I learned in treatment for anorexia was how much the symptoms of my eating disorder (obsession with food, increased anxiety and insomnia, agitation, hyperactivity) were as much symptoms of starvation as they were symptoms of anorexia. Not that this made eating any easier--it didn't--but it helped put a context to all of the frightening thoughts and compulsions I was having. Eating seemed to make them worse, but only after a while did eating make them somewhat better.
Undernutrition may actually be at the core of many of the traits and symptoms researchers initially thought were caused by anorexia. Many people with anorexia are probably more obsessive, anxious, and perfectionistic than average; since these traits existed before the eating disorder, they aren't caused by undernutrition, but they sure can be exaggerated. Even just a quick read of Keys' starvation study indicates that many of the behavior changes brought about by semi-starvation can be significant. Many brain imaging studies of anorexia are performed after weight restoration and a period of recovery and normal eating because starvation has such profound effects on the brain.
There have been numerous studies that have reported on psychological changes that occur during refeeding (Konrad et al 2007), but two interesting studies appeared within the past week that seemed to emphasize the role of refeeding in the psychological recovery from EDs.
The first article was from the French journal Encephale, which looked at the relationship between social phobia, anorexia, and the stage of treatment (Coulon, Jeammet, and Godart, 2009). Because the journal is in French, I'm going to have to stick with the abstract, but the results were still interesting. Social phobia has been loosely associated with AN, but the researchers were trying to figure out whether the social phobia might be a by-product of malnutrition rather than an actual trait of the anorexia sufferer. In this sense, it's kind of the proverbial chicken-and-egg question: which came first, the undernutrition or the symptoms of the eating disorder?
And what did the researchers say about how stage of treatment in anorexia affected social phobia? They found a correlation between social phobia and symptoms of AN as well as "total clinical picture" of the patient, but no relationship between social phobia and nutritional status (as measured by BMI). The researchers concluded that "We therefore feel that a diagnosis of social phobia can only be confirmed after an acute state of AN, thus allowing for preferential treatments. Other studies must be conducted in order to continue to explore the links between social phobia and AN."
This doesn't preclude the pre-illness onset of social phobia--in fact, a 2004 study found that approximately one in five ED sufferers met the diagnostic criteria for social phobia before the onset of their disorder (Kaye et al, 2004). However, due to the eating disorder, social phobia can appear in a person who had no previous symptoms of the disorder. So is that social phobia a true, independent disorder, or is it related to undernutrition? This study says that social phobia might be related to undernutrition, but we don't know for sure yet.
The second study looked at the hypothesized relationship between anorexia and autism spectrum disorders (ASDs; Time Magazine had a good article earlier this year on the issue that I blogged about here). Specifically, the study looked at the difficulties people with AN have with respect to the emotional Theory of Mind (eToM), with understanding and interpreting others' emotions (Oldershaw et al, 2009). People with ASDs often have difficulty understanding other people's emotions, and the fact that AN sufferers also had difficulty with this seemed to be a neurological link between the two disorders.
The researchers compared a group of currently ill AN patients with both recovered AN patients and healthy controls, and found that the emotional deficits seen in acutely ill AN patients had essentially disappeared in the recovered AN patients. Furthermore, there were few differences in emotional tasks in recovered AN patients and healthy controls, which indicates that the emotional deficits are more related to the current state of undernutrition than they are a person's temperament.
Conclude the researchers:
These findings indicate almost complete normalization of emotion recognition ability as well as the restoration of eToM in recovered patients, despite the observation of difficulties in both domains in currently ill patients. Findings suggest that similarities between AN and ASD in poor eToM are restricted to the currently ill AN state and such difficulties in AN may be a factor of starvation.
However, other similarities between AN and ASDs remain, such as difficulties with set-shifting and impaired central coherence (i.e., you can't see the forest because of the trees) that seem to extend long beyond recovery. That, however, is its own blog post that will hopefully be up soon.
4 comments:
Unfortunately I wasn't able to download the full paper (Oldershaw et al. 2009) from PubMed; I have only read the Abstract. I note from the Abstract that the study was cross-sectional; i.e. comparing ill and (weight) recovered anorexic patients with healthy controls. I'd be interested to see the results of a longitudinal study with repeated measures on the same participants in response to intervention (re-feeding).
The autism spectrum is very large and includes a variety of components apart from ToM, which is why many researchers focus on autistic traits rather than autism per se. The available evidence suggests that some (not all) people with anorexia nervosa (AN) or a history of the illness possess a varying number of autistic traits. Perhaps the more traits they possess, the harder full recovery actually is?
From a personal perspective, I do have an ASD. It's relatively mild, but it certainly made my childhood difficult because I was socially 'retarded' relative to other kids of the same age - yet academically advanced. I did have close friends, but it took me a long time to 'work people out'. Similarly, they struggled to understand me and my quirks (including poor eye contact). Many didn't try and I was bullied as a kid. My ASD was a big factor in the development of my AN because I became very anxious at puberty when my body changed, alongside the 'social rules'. I effectively withdrew into AN to escape from the world and to create my own, highly controlled world (not that this was a conscious 'choice').
Gillberg et al. have shown that people with longstanding AN often had childhood social difficulties and repetitive behaviours - and many more autistic traits than people who have a more transient form of AN. They are also less responsive to (e.g.) family therapy.
I imagine that research in this field will conclude that autistic traits can contribute to the development and maintenance of AN, and that starvation enhances these traits, but only a small number of people with AN actually qualify for a diagnosis of ASD.
Cathy,
I agree with your last paragraph whole-heartedly. I see a link between AN and OCD as well; that doesn't mean everyone with OCD has an eating disorder, nor that everyone with an eating disorder also has OCD. But I'm guessing there's still some overlap in neural circuitry.
Social situations are not my strong point, perhaps because I'm over-analyzing everyone's reactions. I have always felt more comfortable with teachers, professors, etc, than people my own age (until my mid-20s).
You're right about the cross-section vs. longitudinal study, in that repeating the measurements on the acutely ill AN patients after weight restoration would have been more valuable. However, this is probably a good study to apply for funding for a longitudinal study. What I think would be interesting to see is if there are any differences in these eToM tasks between those who are able to maintain their weight and those who slip backwards. I would expect there would be a difference based on nutritional status, given this study, but it would be interesting to see if there are any predictive factors during acute illness that could possibly be targeted with therapy to improve outcome.
I'm going to go to the UK to visit you sometime, and we are going to have one giant nerd-fest! :)
Lol - I'd enjoy some nerdy debate Carrie; I am happily geeky! Oh, and I'd have to warn you that I'd harp on for hours about my cats :)
I imagine that the IoP group will follow these patients up longitudinally, but were keen, meanwhile, to get the initial cross-sectional data published ASAP.
I agree with your remark about OCD and AN. Personally I feel that both ASD and OCD contributed to my AN. In fact, I seem to have all the traits that increase vulnerability to obsessive and ritualistic behaviours, including AN...
With regard to your comment about eToM and risk of relapse: Personally, difficulty understanding others, fear of change/unpredictability and fear of unfamiliar social situations has had a huge (negative) impact on my recovery from AN. AN kept me so busy (counting calories, exercising ritualistically etc.) that I didn't need to worry whether or I 'fitted in' (to society). Without AN I felt 'lost' in the world, so I somehow developed a collection of alternative obsessive and repetitive behaviours...
Nowadays my struggles don't concern my weight or calorie counting; although I am still slightly underweight, I fit very few of the criteria for AN. However, I do struggle hugely with anxiety - and I have many repetitive behaviours and obsessions. I am very fortunate to have lovely parents amd some wonderful, close friends who find my quirks amusing...
Has you kitty settled in to your new home?
One part I don't understand about this first study is -- if there had been a correlation between undernutrition and social anxiety wouldn't there have also been a correlaiton between current BMI and social anxiety/phobia? Undernutrition doesn't mean a low BMI, but a low BMI is usually accompanied by undernutrition. . .
From my understanding of what you said, the researchers found a correlation between the entire clinical picture of AN and social anxiety. Could it be that people with social anxiety are more likely to be predispoed to AN or vice versa?
A:)
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