Endophenotypes and Biomarkers in Eating Disorders: Genetic Underpinnings, Personality Traits, Vulnerabilities – Part 2

This post continues the discussion of the chapter on eating disorders by Carolina Lopez, Marion Roberts, and Janet Treasure from The Handbook of Neuropsychiatric Biomarkers, Endophenotypes and Genes (2009). Part 1 focused on neurotransmitter biomarkers, and this second part will focus on the neuropsychological biomarkers.

NEUROPSYCHOLOGICAL BIOMARKERS

Attentional biases

Attentional bias is the tendency for individuals to attend to or be distracted by emotionally relevant stimuli over neutral stimuli. Attentional biases have been observed in several studies:

  • Current AN and BN individuals showed bias towards food, body-related stimuli.
  • Past AN but not past BN showed bias towards body shape concerns.
  • Both current and “long-term recovered” AN showed “abnormally higher activation in the medial prefrontal and anterior cingulate cortices in response to food stimuli using fMRI [brain imaging]” (232)

These biases can be minimal but annoying: waiting in line at the pharmacy, staring into space and finding your focus … Continue reading →

Endophenotypes and Biomarkers in Eating Disorders: Genetic Underpinnings, Personality Traits, Vulnerabilities – Part 1

There have been some interesting discussions on the F.E.A.S.T. Facebook group over the past month regarding the role of genetics, personality traits, environmental factors and their role (or lack thereof) in the development of eating disorders and their prognosis. A parent group may seem like an unlikely forum for several hundred-odd comment threads on etiology; however, what we (caregivers, patients or clinicians) believe to underlie these disorders naturally informs our attitudes, decisions and choices with regards to treatment and our relationship to the disorders themselves:

Is this something they will have to manage their entire life?
Does anyone ever fully recover?
I had bulimia as a young adult and now my son has an eating disorder, too – did I pass on “bad genes”, bad habits, or is it a coincidence?
Is her rigidity and anxiety merely a side affect of starvation, or should we treat those as an underlying
Continue reading →

Maintaining Change Following Intensive Eating Disorder Treatment

It is a relatively well known fact that eating disorders have a high relapse rate and many people, myself included, find themselves in multiple intensive – residential, inpatient, even partial hospitalization – treatments. One may ask if such intensive treatments really work or if long term intensive care is just a band-aid of sorts. I know I’ve had to ask myself, “why is this going to work this time when it hasn’t worked in the long run before.”

There is even debate in the field on whether residential treatment actually has evidence supporting its effectiveness (see Tetyana’s post here). I can speak from experience that the various intensive treatments I’ve personally done have saved my life and given me more perspective, skills training, and support than I could have had otherwise. However, despite having made significant changes, I’ve had more than my share of slips and relapses.

I … Continue reading →

Is Anorexia Nervosa a Version of Autism Spectrum Disorders?

Patients with anorexia nervosa often have difficulties recognizing and regulating emotions. This  conclusion that is largely based on data from  common tests such as Reading the Mind in the Eyes assessing  emotion recognition, and questionnaires like Difficulties in Emotion Regulation Scale (DERS) assessing emotion regulation (see my post here).  Although that study compared currently ill patients with healthy controls (thus raising the possibility that the resulting data was due to the effects of starvation or due to the chronic nature of the ED  in the sample, ~7.5 year on average), there is some evidence that some of these difficulties persist post-recovery.

Individuals with autism (ASD, or autism spectrum disorders) also have difficulties with emotion recognition and regulation, leading some investigators to hypothesize that AN and ASD may share common etiology. Providing further support for this hypothesis are studies suggesting that AN might be overrepresented in ASD and … Continue reading →

Diabulimia: Disordered Eating in Type 1 Diabetic Patients

Type 1 diabetes mellitus (DMT1) is a lifelong chronic disorder that occurs when the body is unable to produce enough insulin – a hormone that is required for carbohydrate metabolism. Patients must learn to manage their disorder by monitoring their blood sugar levels on a regular basis, carefully selecting the foods they eat and how much exercise they do. Before insulin was extracted and purified (at University of Toronto!), type 1 diabetes, which usually occurs in children and adolescents, would very quickly lead to death – the body, unable to take in the very thing it needs to survive.

Unfortunately,  patients with type 1 diabetes are at increased risk of developing eating disorders or disordered eating behaviours. Diabulimia refers to an eating disorder in patients with DMT1 who reduce or skip insulin doses to reduce their weight.

The exact prevalence rates vary study by study, depending on the population sample, … Continue reading →

Emotion Recognition and Regulation in Anorexia Nervosa

Should anorexia nervosa (AN) – or subtypes of AN – be classified as part of the autism spectrum disorders (ASD)? That’s a question that has been receiving some attention in the literature in the last few years, although there are only a handful of studies, most of which are small and limited in scope (thus limiting interpretation of the results).

In the Time Magazine article  “A Genetic Link Between Anorexia and Autism?” the author mentions a study – which I decided to cover today – on emotion regulation and recognition in patients with AN. It is not directly evaluating the link between AN and ASD, but it is related and a good starting point. I was originally going to write about two papers, but I will save the other one  (Is anorexia nervosa a version of autism spectrum disorders?) for another time.

The study design in this paper … Continue reading →

The Ethics of Force Feeding in Anorexia Nervosa

I’m cheating. This is not a real blog post.
I’m going to plug a piece I just wrote for another publication/blog (see below) called:

Anorexia Nervosa: The Ethical Dilemma of Force Feeding. Check it out, leave a comment.

I’m “cheating” in part because I’ve been busy  (mostly writing my thesis, but also writing and editing other articles, editing essays, tutoring, and all sorts of fun things that leave me with less time for the blog), and in part because it is relevant and I think it will be of interest to SEDs readers.

Here is the story:
A friend of mine asked me to write an article for Inquire UofT. Inquire is an interuniversity publication and the University of Toronto chapter is at its infancy–as is their blog. My friend told me I could write about anything I wanted but the topic had to be current and controversial. … Continue reading →

Genetics: Friend or Foe in Ending Eating Disorder Stigma?

Refrigerator mothers or the idealization of thin models? Toxic families or toxins in our diets? Oh, if only determining the cause (because it has to be just one, right?) of eating disorders was that simple. All behaviour has a biological basis, a neurobiological correlate. The way our brains function—and the resulting behaviours — is due to complex interactions between our genome, epigenome, and the environment. Eating disorders do not have a single cause; we cannot put the blame solely on families, or thin models, vanity or genetics.

As a science grad student, I am interested in how non-scientists interpret scientific findings on mental disorders, particularly eating disorders. With respect to eating disorders, I am interested in how patients’ understanding of the science shapes the way they view themselves and their eating disorders, as well as how it shapes their treatment and recovery.

In a recent paper, Michele Easter wanted to find out … Continue reading →