Quantitative

Emotion Fluctuations in Anorexia and Bulimia Nervosa: A Rollercoaster or Not So Much?

Tetyana 2 Comments

Restricting, bingeing, and purging are powerful ways to regulate emotional states. However, these behaviours probably play different roles in emotional regulation. Whereas restriction is hypothesized to pre-empt the onset of highly emotional states, bingeing and purging is thought to act as a coping mechanism to deal with overwhelming emotional states once they’ve already been activated. 

In BN there is abundant evidence that the binge–purge cycle functions as a means of emotion regulation. Binging [and I would arguing purging too! ] facilitates a temporary suppression of painful self-awareness and helps the self to dissociate from painful emotions or to block negative affect as demonstrated in both laboratory studies and diary studies in daily life.

In AN, restrictive eating patterns have been linked with a narrowing of emotional functioning, flattening of affect and lack of outward display of emotion. As such, Waller, Kennerley, and Ohanian (2007) argue that both binge– vomit-cycle and

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The Benefits of Starving – Part II (Restricting Reduces Anxiety in Anorexia Nervosa)

Tetyana 10 Comments

What is different about anorexia nervosa sufferers that, in contrast to most dieters, enables them to maintain a persistent calorie deficit? Although no one can truthfully claim they know the full answer to that question, we do know that part of the answer most likely lies with serotonin (5-HT), a molecule that neurons use to communicate with each other.

I’ve written about serotonin in the context of anorexia nervosa before, so I’ll just do a brief summary of the important points here:

  • Serotonin has a lot of functions in the body; it plays a role in regulating appetite (satiety), sleep, mood, behaviour, learning and memory, and a variety of other things
  • Serotonin has been implicated in obsessionality, harm avoidance, and behavioural inhibition
  • Alterations in serotonin function have been linked to many disorders, including depression, OCD, anxiety, and eating disorders
  • Serotonin is made from tryptophan, an essential amino
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CCK and the "Hunger Trap" in Anorexia Nervosa (Why Gaining Weight is Hard)

Tetyana 4 Comments

Cholecystokinin (CCK) is a digestive hormone that stimulates fat and protein digestion, and promotes the feeling of satiety. CCK is released after food consumption to promote digestion (by releasing digestive enzymes from the pancreas and stimulating bile secretion). In rats and monkeys, injection of CCK induces satiety, though it seems (from what I’ve skimmed), the extent to which CCK regulates food intake in humans is not well-established. Previous research on the role of CCK in anorexia nervosa (AN) has found conflicting results, in part because of methodological issues related to measuring levels of CCK. In a recent study, Cuntz and colleagues (2013, freely available online), having developed a better assay for measuring CCK, wanted to clarify its role in AN patients.

The authors had the following goals and hypotheses (I omitted one):

  • Objective 1: Compare CCK levels between AN patients and healthy controls before and after a meal
  • Objective
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Why Banning Pro-Ana is a Bad Idea

Tetyana 5 Comments

Is banning content that is thought to “promote” eating disorders such as anorexia nervosa (pro-ana) a good idea? I want to put aside the question of whether the goal is even possible (I would argue that it is not) and focus instead on what might happen if pro-ana content is banned or threatened to be banned from mainstream social networks, blogging platforms, and web hosts.

If you only read mainstream news media, you might think that pro-eating disorder websites are evil communities seeking to lure unsuspecting young adolescents into a world of extreme dieting, lying, and who knows what else, all under the guise of being a “lifestyle.”

Well, as I’ve blogged before, the picture is not so simple:

Ultimately, it seems that the support on offer on pro-ana websites is—for all the scare stories about “purging tips” and users egging one another on with their latest BMIs—little more

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Comorbid PTSD and Eating Disorders: Can Treating One Improve The Other?

Tetyana 7 Comments

Women with bulimia nervosa are three times more likely to struggle with PTSD than women without eating disorders, according to a study by Dansky and colleagues (1997). In that study, 37% of individuals with bulimia nervosa had lifetime PTSD, compared to 12% of women without eating disorders. That’s almost two in five.

Treating eating disorders is hard, but treating eating disorders with comorbid conditions is way harder. There is no consensus, it seems, as to what disorder(s) to treat first, or whether they should be treated simultaneously:

Brewerton (2004) suggests that eating problems should be addressed prior to treating PTSD because bingeing and purging contribute to a state of physical and emotional dysregulation. Fairburn (2008), however, suggests that significant comorbid disorders be treated prior to beginning CBT for eating disorders.

The issue is quite complex,

For example, the presence of severe depression, of which hopelessness and difficulty

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How Much Can We Learn About Eating Disorders From Animal Research?

Liz 4 Comments

I have been studying the neurobehavioral aspects of food and drug reinforcement for the past 5 years (read more about it on my profile page). This involves using rats to mimic basic human behaviors surrounding food and drug intake. I then manipulate various neurotransmitter systems by using drugs and observe the effects this manipulation has on the behaviors I am interested in.

What’s important to this type of research is that we constantly challenge and evaluate the validity of using these animal models to study complex human diseases and disorders. Validity can be divided into several categories, but I’m going to focus on two in particular and relate them to an animal model of binge food intake.  These two types of validity are predictive validity and construct validity:

  1. Predictive validity, when comparing animal research to human research, refers to the ability for some measure of animal behavior
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Calorie Restriction, Anorexia Nervosa, and Memory Gaps

Tetyana 48 Comments

This post has been translated into Russian by Polina here.

I have often heard anorexia nervosa sufferers complain of “memory gaps,” particularly during the times they were really sick. As if they weren’t really there.  It can be scary and unnerving, to say the least. A few months ago, a Tumblr user asked me about this:

Hi Tetyana, I’m not sure if this is merely based on my own subjective experience of if there is any grounding at all, but I was wondering if there could perhaps be a link between EDs and a sort of memory loss. It’s hard to describe but I definitely seem to have huge “gaps” in my memory of during that time, as if I selectively block things out. I have limited inaccurate knowledge with regards to memory on a molecular/neurological basis so I do not know if there’s anything there. Perhaps with calorie

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Posttraumatic Stress Disorder in Women with Bulimia Nervosa

Tetyana 6 Comments

Posttraumatic stress disorder (PTSD) is 3-5 times more prevalent in individuals with bulimia nervosa (BN) than those without (Dansky et al., 1997). However, the relationship between PTSD and BN–in particular, how PTSD might affect or moderate bulimic symptoms–remains largely unexplored. In a recent study, Trisha Karr and colleagues followed 119 women (20 with PTSD and BN, and 99 with BN only) for a 2 week period to investigate whether participants with comorbid PTSD + BN differed from those with BN only on the:

  1. Levels of negative affect (negative emotional state/mood) and affect variability (fluctuation between negative and positive states)
  2. Frequency of bulimic behaviours
  3. Relationship between emotional states (negative or positive affect) and bulimic behaviours

They used the ecological momentary assessment (EMA) tool to track behaviours and emotional states close to when they occur. I’ve blogged about a study using EMA before (‘What’s The Point of Bingeing/Purging? And Why … Continue reading →

The Genetics of Thin-Ideal Internalization

Tetyana 7 Comments

The Tripartite Model of body image dissatisfaction postulates that three factors (peers, parents, and media) affect body image dissatisfaction and disordered eating through thin-ideal internalization and appearance comparison.

Thin-ideal internalization is the extent to which one accepts or “buys into” socioculturally defined beauty standards of thinness. The idea is that the more someone internalizes these standards, the more likely they are to engage in behaviours to achieve their “ideal”, and the more likely they are to develop an eating disorder.

A growing number of of studies have been done evaluating the validity of this model. Although I’m not well-read on the subject, it does seem like there is a growing number of studies showing an association between thin-ideal internalization and disordered eating practices.

But is the picture complete? Are peers, parents, and media the only or even the main factors that influence the extent of … Continue reading →

Bingeing and Purging: Keeping the “Positives” and Eliminating The Negatives?

Liz 11 Comments

I have been fascinated and perplexed by reports of the seemingly invigorating and anxiety reducing effects of bingeing and purging (purging by self-induced vomiting). Personally, I cringe at the idea of self-induced vomiting and have always wanted to avoid vomiting at all costs, including during food poisoning. The insight from recent blog entries and the subsequent comments has made an impact on me. I see that the motivation to engage in bingeing/purging behavior can be intense and can provide an effective way increase positive affect and reduce stress. The ameliorating effects of bingeing/purging remind me of drug addiction, with bingeing/purging behavior as the “drug.”  This made me wonder, what happens in the brain to impart such “addiction-like” reinforcement?

I know there are reports of opiate and endorphin release following purging, but to me, this seemed like an effect meant to counter the intense aversion (and discomfort?) of the act … Continue reading →