13 questions - Anorexia Nervosa
1. Describe the diagnostic criteria and the symptoms of anorexia:
Answer:
DSM IV →
BMI <17.5 (kg/m2) → relatively high, in clinics BMI is 12-15.
Amenorrhoea (no menstruation, low fat percentage = low leptin = disturbed hormone
regulation)
Distorted body image
Fear of gaining weight
DSM V →
Restriction of food intake leading to weight loss or a failure to gain weight resulting in a
"significantly low body weight" of what would be expected for someone's age, sex and height.
Fear of becoming fat or of gaining weight.
Have a distorted view of themselves and of their condition. Including the person thinking that
they are overweight when they are actually underweight, or believing that they will gain weight
from eating one meal. A person with anorexia might also make excuses or deny that there is a
problem with being at a low body weight.
2. There are two types of anorexia. Describe the differences:
Answer: The two types of AN are the restricting type and the binging/purging type. The
restricting type can be identified as the patient highly restricting their food intake. In contrast,
the binging/restricting type is characterized by regularly engaging in binging episodes and
purging behaviors, such as self-induced vomiting and/or the misuse of laxatives or diuretics.
3. In what way does culture play a role in anorexia?
Answer:
1. Culture has a very important role in AN. In a study, the prevalence of eating disorders
(ED) was tested in Curacao compared to NL. Black women were significantly less
affected by ED than white women. Incidents of ED in Curacao were much lower
, compared to NL, because the population in Curacao is mainly black. However, white
women from Curacao almost have the same prevalence of ED as white women from NL.
Moreover, moving to NL as a black person from Curacao makes ED comparable to the
white population. → where you live influences your chances of developing an eating
disorder.
2. Cultural influence can also be seen by the prevalence rates between rural and large
cities. For bulimia, there are differences between regions and it is way more in the large
cities. For anorexia, there is not that much difference between regions in the
Netherlands.
3. Also, social media has a role in developing anorexia, due to the unrealistic beauty
standards that develop because we are more used to seeing distorted images of people
due to photoshop and such things.
4. How is AgRP related to anorexia?
Answer: Dieting will lead to decreases in the adiposity signals leptin and insulin and in the
hypothalamic POMC, while NPY and AgRP go up. When leptin goes down, AgRP increases to
make you hungry again. But when AgRP is disturbed and doesn’t go up when leptin goes down,
when you diet, you won’t feel an increase in hunger. AN patients have chronically low AgRP
(12% of the AN in Utrecht have a dysfunctional AgRP gene).
5. Who can be used as controls in anorexia research?
Answer: Actually, this is difficult to find because even extremely fit people cannot compete with
the level of activity of AN patients. However, ballet students can be used as controls as they are
very thin, highly active but they are also at risk of developing anorexia.
6. What is known about the serotonin levels in anorexic patients?
Answer: Serotonin levels in AN patients are low. Firstly, this could be because serotonin is
synthesized from the amino acid tryptophan and when restricting your food intake you don’t get
enough nutrients for the biosynthesis of serotonin. Secondly, recovered AN patients have
reduced 5HT2A receptors. However, the problem is that it cannot be said if it is the cause or
consequence of the disease because there is no data prior to onset of AN.
, 7. Is OCD the cause or the consequence of anorexia? Describe what both views mean
regarding the required treatment.
Answer: It is important to consider whether the OCD-like symptoms are the cause or
consequence of anorexia because this is important for the consideration of treatment. Does it
start with anxiety/depression/OCD which leads to anorexia, or does it start with anorexia which
results in anxiety/depression/OCD. Treatment of anxiety/depression/OCD with SSRIs led AN
patients to lose more weight compared to controls, which is very bad for AN patients. So this is
not a possible treatment for anorexia. However, it does diminish the depression symptoms,
because when the subjects lost weight due to the drug, they did not get more depressed, which is
to be expected after more weight loss. Evidence for treatment of anorexia and looking at OCD as
a consequence of anorexia is the Mandometer treatment: Weight gain after drugs-free treatment
with the Karolinska Mandometer is followed by a reduction in anxiety, depression and obsessive
behavior: If you treat the eating, the OCD disappears without specific treatment of that.
8. Describe anorexia based activity (ABA) and if this is a cause or a consequence of the
eating disorder
Answer:
Anorexia based activity is a phenomenon that has been demonstrated in a wide variety of animal
species. If you restrict food, the subject is going to move. Which is counterintuitive, because you
would think you have to save energy! In anorexic patients they also tend to be hyperactive,
which is related to the food restriction. In animal models, this is also shown: the more you
restrict food, the more a rat will run in the running wheel.
It seems that this is a consequence of the eating disorder: Dieting leads to weight loss and the
weight loss leads to hyperactivity. This happens because weight loss activates the NPY release
and increases appetitive behavior, which leads to hyperactivity. And this hyperactivity is
rewarding, dopamine and orexin levels go up, which causes the Anorexia nervosa patients to
become addicted to dieting and hyperactivity, leading to further weight loss.
9. What has the Minnesota Starvation experiment taught us about anorexia?
, Answer: In the Minnesota Starvation experiment, the participants lost a significant amount of
their body weight in a short period of time. There were several physical symptoms, such as
restlessness, hyperactivity, reduction of body temperature, and of course massive decrease in
their body weight. Psychological symptoms included increased moodiness, depression,
impulsivity, and compulsive and rigid tendencies (become upset with any breaks in routine).
Interestingly, participants were mostly preoccupied with food. The physical and psychological
symptoms resemble the symptoms of AN. This could be interpreted that the symptoms associated
with weight loss cause the OCD like symptoms typically seen in AN.
10. Is there an animal model for Anorexia research and if so, how does it work?
Answer:
There is one animal model for AN: You give a rat unrestricted and voluntary access to a running
wheel but restricted access to food (only 1 hour per day). Normally, sedentary and running rats
will remain their constant body weight because the running rat will eat more as it burns more
calories and the sedentary rat will eat less since there is no need for high caloric intake.
However, when restricting the food the running rats will increase their running activity.
Moreover, the more you restrict the food the more running activity can be seen, where the rats
will essentially run themselves to death. This is what is called anorexia based activity (ABA).
The first day, the running rats eat 100% of the food but the following days they constantly keep
decreasing the food but keep running more ( second day, they eat 20%, the following days, they
eat around 25-30%). While the sedentary rats will eat 50% of the food, and not run.
11. What is happening in the brain of the ABA model participants and what does this tell us
about possible treatments for humans?
Answer:
Dieting will decrease leptin, insulin, and POMC, and increase NPY and AgRP. Norepinephrine
also increases and gives you the signal to eat carbohydrates. In addition, orexin goes up and
increases eating and running behavior. This leads to an increase in dopamine outflow and the
reward system is activated due to hyperactivity. When given an orexin (R1) or dopamine (DA1)
antagonist, the hyperactivity will decrease and ABA model subjects will not develop the running
and eating behavior.
