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Feb 15 2013

Psychopathology Sum-Up: Bulimia Nervosa

[This is a guest post by Tetyana Pekar]

Tetyana is about to defend her MSc in Neuroscience at the University of Toronto. She is passionate about making eating disorder research more accessible to the public. She writes the Science of Eating Disorders blog where she aims to make sense of the latest findings in eating disorder research for lay audiences. She can be reached at [email protected]

What is bulimia nervosa?

Bulimia nervosa (BN) is a serious eating disorder (ED) characterized by cycles of bingeing and compensatory behaviors. The most common compensatory behaviour is self-induced vomiting, but others include laxatives, diuretics, fasting, and excessive exercise. It is a common misconception that all BN patients self-induce vomiting—not so, while most do, there is a sizeable minority that does not (Keski-Rahkonen et al, 2009).

Individuals with BN are typically normal weight or overweight. This isn’t by chance; it is almost by definition. If someone binges and purges but is underweight, they will most likely be diagnosed with anorexia nervosa (AN) binge/purge subtype. Importantly, these diagnostic categories are not static, distinct groups, as over 50% of those diagnosed with restricting type AN cross over to bingeing/purging type within 5 years of ED onset, and about one-third cross over to BN (Eddy et al. 2008). So, take these diagnostic categories with a grain of salt.

Prevalence & Mortality

EDs have a high mortality rate, but keep in mind that prevalence and mortality statistics always depend on the duration of the study, the study size, and the population studied (among other things). However, most studies converge on a lifetime prevalence of BN somewhere between 1-2% (0.9-1.5 among women and 0.1-0.5% among men) (Smink et al., 2012).

The standardized mortality ratio (bulimia patients/normal, age-controlled population) for BN varies from ~2-5 (Arcelus et al., 2011). In one study of 906 individuals with BN, 3.9% died in the mean follow-up of 19 years, with suicide accounting for 23% of those deaths (Crow et al., 2009).

Causes

As much as people like the point the finger at the media and ‘thin culture,’ this explanation cannot be the whole story. After all, we are all exposed to images of thin models, and yet only 1-2% of women experience BN at some point in their lives. What is it about this percentage of women that makes them susceptible to BN?

Certainly, genetics plays a role.

Family studies are useful for determining if a particular disorder aggregates in families, though they cannot decipher if that aggregation is due to genetic risk factors of shared environmental factors (such as an over-emphasis on weight and appearance). These studies have shown that first-degree relatives of BN patients have a 4.4-9.6 higher likelihood of having BN than relatives of healthy controls (Kassett et al., 1989; Stein et al., 1999; Strober et al., 2000; ).

Twin studies are another good way to delineate the effects of genes and environment. These studies have shown that between 54-83% of the variation we see in BN is accounted for by genetic effects (Bulik et al. 1998, 2010; Kortegaard et al. 2001; Wade et al. 1999). (Note, this DOES NOT mean genes cause 54-83% of the disorder.)

This does not mean there are genes for BN (genes code for proteins, after all). However, commonly occurring temperament and personality traits might account for some of the genetic risk factors. Traits such as perfectionism, obsessionality, sensitivity to reward and punishment, and impulsivity often occur before ED onset and persist following recovery for many patients (Kump et al., 2004).

In addition, neurotransmitter systems, such as serotonin and dopamine, appear to modulate a lot of the traits associated with eating disorders. Indeed, serotonin might play an important function in the development of BN (and, along with the effects of estrogen, might partly explain why females are much more likely to suffer from EDs than males.)

It is almost important to emphasize that EDs are not “Western” disorders that arise solely due to an overemphasis on thinness. To provide just a few examples, blind women are not immune to EDs, and Iranian women living in Tehran exhibit similar levels of disordered eating behaviours as their counterparts in Los Angeles.

Behaviour does not occur in a vacuum. Genetics and environment both play a role. (For more on causes, see this post.)

Comorbidities

Eating disorders are generally highly comorbid with depression and anxiety disorders (Blinder et al., 2006). As mentioned earlier, patients with eating disorder tend to score high on perfectionism, neuroticism, impulsivity (particularly for BN patients), harm avoidance and obsessive-compulsive disorder. Among BN patients, the most common personality disorder appears to be borderline personality disorder (Sansone et al., 2005).

Treatment & Outcomes

Treatment for BN can include outpatient, inpatient, and/or residential treatments, among other things. As readers of FtB are well aware, any hard to treat diseases and disorders always attract pseudoscientific treatments. So, what treatments are evidence-based?

SSRIs, interestingly enough, have been shown to be effective in reducing the frequency of bingeing and purging in BN patients compared to placebo, particularly fluoxetine/Prozac (reviewed in Flament et al., 2012 and Hay et al., 2012). Cognitive-behavioural therapy is also widely considered to be an evidence-based treatment for BN (though, I have my reservations) (Murphy et al., 2010). In the end, the most important thing is to have a strong therapeutic alliance between the patient and the treatment team/therapist, as well as motivation to change.

In terms of outcomes, the results depend on length of follow-up, duration of illness, and sample population (i.e., how sick are the patients?). However, one large review found that about 45% of BN patients fully recovered, 27% improved, and 23% had a chronic course (Steinhausen et al., 2009).

Problems with the DSM

Compared to the problems with anorexia nervosa (AN), there are not as many. However, here are two things that annoy me:

  • Arbitrary frequency and duration criteria (2x/week for 3 months) (This will be reduced to 1x/week in the DSM-V.)
  • Too focused on weight (“compensatory behavior in order to prevent weight gain” and “self-evaluation is unduly influenced by body shape and weight”). These can certainly be true, but they don’t have to be. Bingeing and purging can just be a tool to regulate emotions.

Common Myths

Here are some other common myths that I haven’t mentioned yet:

  • BN patients throw up everything they eat. No, but some do, sometimes. The frequency and extent of behaviours varies a lot.
  • BN patients should just eat 5-small meals a day. Well, yes, but the problem has got nothing to do with not knowing how to eat well in theory.
  • BN is on the increase. Actually, studies suggest is pretty stable or even decreasing.
  • It is an effective weight control method (i.e., it is safe). I suppose, if you are okay with the plethora of medical complications (including death).

And one that bothers me the most:

  • BN is just about vanity. Actually, for me, bingeing and purging is incredibly anxiety reducing, and I’m usually symptomatic when I’m stressed, overwhelmed, or feel like crap about myself (not productive enough, for example). A sense of calmness and tranquility often follows self-induced vomiting (and I’m not alone in feeling this way).

Hopefully I’ve covered the basics. If you want to know more about BN, feel free to ask me questions in the comments, send me an email or check out BN-related posts on my blog here.


Tetyana was diagnosed with restricting type anorexia when she was in grade 10, started bingeing and purging at the end of first year in university. Her eating disorder has been all over the place, and she enrolled in outpatient treatment in high-school. She will be attending Women in Secularism conference. (Where I finally get to meet her!) You can follow her on Twitter.

Previous Psychopathology-Sum Ups:

Specific Phobias
Bipolar Disorder
Types of Antidepressants

11 comments

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  1. 1
    And How

    Ashley, I enjoyed this post.

    I have a question if you care to comment. Do you think that it is possible that young men and men who become addicted to steroids could possibly share the same psychopathology?

    I see a lot of parallels. Including, that men who are hooked on steroids will work out obsessively. I would argue they are not working out for health reasons, but rather emotional reasons. Of course, the difference is that working out, is generally speaking a healthy activity so it is viewed differently. But the goal for working out is different as well and is combined with the dangers of steroid use. To me, men who use steroids have obvious serious emotional issues going on and they seem rooted in the same thinking as female eating disorders.

    We aren’t going to have worldwide issue of steroid use among men because most of the world’s men don’t have access to these drugs, nor do they have the cultural pressure of pushing the perfect body craze like is the case here in the US.

    Please understand, in no way am I trying to discount female eating disorder problems in making a statement well men have problems too. My bringing this up, is actually the opposite. I am wondering whether you see any parallels in the psychopathology between men and women as it relates to my comments?

  2. 2
    And How

    I just noticed this was a guest post. So, my queston is really for Tetyana as well.

  3. 3
    Kate Donovan

    For me, I see parallels in only the most ephemeral sense. The psychopathology of eating disorders doesn’t necessarily link directly to obsessive exercising. Furthermore, the thoughts behind exercising in eating disorders seem to be very very different than the motivations behind those abusing steroids. The similarity between the two things your describing strikes me as superficial–appearing the same, but different motivationally and in terms of treatment. However, Tetyana may have other thoughts.

  4. 4
    And How

    I’ll expand a bit.

    My thoughts were that the exercising is parallell to the binging and vomiting; both having the same root cause of emtions playing out with body image. Perfect body for the male (muscles) and ideal body for the female (thin). Both actions, working out and binging/ vomiting have this emotional components in that they ultimately make the person suffering feel better.

    I’m not a doctor or psychiatrist and am not really trying to argue I know what the hell I’m talking about though. Just thoughts.

  5. 5
    Tetyana Pekar (@scienceofeds)

    That’s an interesting parallel that I must admit I never thought about (re: steroid abuse). I can’t really comment on it because I don’t know much about steroid abuse and the effects of steroid on the brain. I can see a better link to exercising because exercising, of course, has lots of effects on the brain, and thus how we feel.

    I don’t want to discount the body image links, because they do exist, but the extent to which they play a role in eating disorders is really overblown, in my opinion. Really overblown. Of course, every female and male feels pressure to look a certain way, and I don’t think that those of us with eating disorders feel it any more or less than any other person. I think that attributing eating disorder behaviours to body image/societal pressure is largely (though not entirely) a scapegoat. Dr. Cynthia Bulik it calls it the “tyranny of face validity.” It seems like a valid idea, and it makes sense, but that doesn’t make it true.

    I have little knowledge about the motivations for steroid abuse, though, and the psychopathology associated with it. So, it is really hard for me to comment on that, unfortunately.

  6. 6
    And How

    I cannot know with any level of certainty, but I also suspect the link to body image is overblown.

    I have a hypothesis that is an extension of the one I have already given. I’ll try to express it in a way that hopefully it makes sense.

    I see many different types of mental disorders share a common root. Namely, that an addictive behavior(s) has developed. To further expand:

    Those with eating disorders have become “addicted” to the behaviors associated with ed’s. The steroid abuser is “addicted” to the behaviors of that problem – steroids and exercise. The sex addict is “addicted” to predatory sexual behavior and sexual release. The person who hoards is “addicted” to collecting. Compulsive hand washing and cleaning hass it’s “addictive” behaviors. And the list goes on and on.

    My question is do all these conditions with “addictive” symptoms share the generalized traits you list: obsessive-compulsive, perfectionism, depression, neuroticism, and I would add lack of impulse control. You mention harm avoidance, but I’m not familiar with that term. Also, it seems to me there is an emotional component to all of these behaviors as well – in that acting on the behavior makes the person feel better and reduces anxiety.

    To my mind, the question becomes why do these “addictions” manifest themselves in the symptoms associated with eating disorders with some, abberant sexual habits with others, aberrant personal hygiene habits with others.

    Other questions, are the general traits simply descriptive and the actual problems are localized to specific areas of the brain? Or are the traits themselves the problem and we can’t yet explain why they shows up as ed with one patient, steroid abuse with another, etc.

    I also believe the nature vs. nurture dilema is always a factor. I would first say, that assuming one’s parents were well intentioned, I do NOT think blaming one’s parents is productive. I don’t even think it is productive if they were abusive. I think the goal should be to understand and make adjustments in one’s perspective and thinking to achieve better health. But I see the links between nurture and mental health issues as undeniable, in what I’ve read.

    I see it that it whenever possible, one should review how one was socialized and allow the therapist to “re-parent” where needed. I am not suggesting, counseling or professional therapy serves as stand alone treatment, just that it is an additional tool to gain opimal health.

    I am not saying all these problems are the same, because obviously they are not. But I have always wondered about what I see as similarities. I think the study of neuroscience is where many answers lie to these questions.

  7. 7
    badgersdaughter

    I’m a middle-aged woman and a diabetic (type 2 non-insulin-dependent) and I have been suffering from anxiety (now thankfully beginning to dissipate with the help of an understanding therapist). For me, my disordered eating,my anxiety, and my blood sugar levels are all closely correlated with each other and with my levels of estrogen and cortisol. I was shocked to realize not long ago that I will occasionally eat to push my blood sugar a bit because it makes me sleepy, and then I have a nap and my anxiety is reduced. I notice it is very difficult to eat in the morning, though, when my blood sugar and cortisol are at their highest, and very difficult to eat in the evening, when I’m anxious because I’m alone and also because it’s really hard for me to go out where there are people. I’m doing better, truly.

    But before I leave this dreadful stage behind, I wanted it to be put on the record that it’s been my experience that disordered eating can be linked to factors, such as cortisol (which in turn effects blood sugar), that are not as well understood. It’ was especially interesting to me to find out that there is an old study done on the diabetes drug metformin to successfully treat many cases of entrenched depression. I’d love to see these connections explored by competent people.

  8. 8
    Tetyana Pekar (@scienceofeds)

    Thanks for the explanation/expansion.

    “Those with eating disorders have become “addicted” to the behaviors associated with ed’s. The steroid abuser is “addicted” to the behaviors of that problem – steroids and exercise. The sex addict is “addicted” to predatory sexual behavior and sexual release. The person who hoards is “addicted” to collecting. Compulsive hand washing and cleaning hass it’s “addictive” behaviors. And the list goes on and on.”

    The addiction analogy is commonly used in eating disorders but it does have problems. What’s the addiction in anorexia nervosa, for example? An addiction to dieting? Hunger? But I do agree that these behaviours have a compulsive component and subsequent release of anxiety/depressive symptoms.

    “Other questions, are the general traits simply descriptive and the actual problems are localized to specific areas of the brain? Or are the traits themselves the problem and we can’t yet explain why they shows up as ed with one patient, steroid abuse with another, etc.”

    None of these would be localized to one brain region, though of course some brain regions are more important than others. I think those predisposed to anorexia nervosa, for example (which often leads to bulimia), find restricting anxiolytic. That’s obviously a risk factor, since most others don’t. It is hard for me to comment on other addictive behaviours, because I just don’t know, but I agree the questions are fascinating.

    We also have to be careful, because having outward similarities doesn’t mean the etiologies are similar.

  9. 9
    Tetyana Pekar (@scienceofeds)

    Thank you for your comment. Those are definitely interesting points. I’ll look up any links with respect to cortisol and disordered eating, I haven’ explored that yet. Thanks!

  10. 10
    karmacat

    I am a psychiatrist who treats patients with eating disorders. I just wanted to thank Tetyana for such a great summary of anorexia and bulimia

  11. 11
    Tetyana Pekar (@scienceofeds)

    :)

  1. 12
    Shared Genetics Between Disordered Eating and Periods (Menses) | Science of Eating Disorders

    [...] By the way, check out my guest post on Ashley Miller’s/Kate Donovan’s blog about bulimia… [...]

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