Neuroscience of Eating Disorders
If you've never had, or never known someone with an eating disorder, you might not feel like this episode applies to you. We promise you, it does, it applies to all of us.
Because when it comes to eating disorders, it just feels so simple. Why can't this person just start (or stop) eating? But what if we told you it has very little to do with eating, and everything to do with how the brain sees the body?
In this month's deep-dive episode, Laine walks us through the science behind the deadliest diagnosis in mental health. Using findings from scientists Riva, Southgate, Tchanturia, Treasure, Stanghellini, Ballerini, and Mancini we discuss things like:
how the brain understands the body
how this can and will rewire the brain
why its so hard to stop
a major takeaway to not only help stop unnecessary death but also change society and create more beauty and self-empowerment in our lives
A small disclaimer: We will be connecting the research to understanding eating disorders to what we learned in both the Neuroscience of Depression and the Neuroscience of Addiction if you want to check those out ahead of time.
If you want to know more ways to be part of our Brain Blown Community, head to www.patreon.com/brainblownpodcast to learn about our offers! If you have any topics you'd be interested in learning more about, please feel free to send us an email at info@brainblownpodcast.com!
We'd love to hear from you.
REFERENCES
Giuseppe Riva, Ph.D. -- Out of my real body: Cognitive neuroscience meets eating disorders
Laura Southgate, Kate Tchanturia, and Janet Treasure --Building a model of the aetiology of eating disorders by translating experimental neuroscience into clinical practice
Giuseppe Riva, Ph.D. -- The Key to Unlocking the Virtual Body: Virtual Reality in the Treatment of Obesity and Eating Disorders
Giovanni Stanghellini, Massimo Ballerini, and Milena Mancini -- The Optical-Coenaesthetic Disproportion Hypothesis of Feeding and Eating Disorders in the Light of Neuroscience
General Outline of Episode
Disclaimer at the very beginning: This episode will likely make more sense if people have listened to Depression and Chemical Addiction
Covering another disorder with outward symptoms that make it seem like they could choose to change their behavior. But from what we learned in the Neuroscience of Chemical Dependency, our drive to seek good feelings is very strong, and those sources of good feelings are not treated equally by any means.
This is the neuroscience of Eating Disorders.
Prevalence -
According to the National Association of Anorexia Nervosa and Associated Disorders 9% of worldwide
28.8 million Americans
Less than 6% of people with an eating disorder are underweight
Most deadly, second only to opioid overdose - one death every 52 minutes
26% have tried to end their life
30% have experienced sexual abuse
A high percentage of comorbidity with another diagnosis
addiction(colloquially)
This is the only diagnosis that is colloquially celebrated and often rewarded
42% of 1st-3rd grade girls want to be thinner.16
81% of 10-year-old children are afraid of being fat.17
46% of 9-11 year-olds are “sometimes” or “very often” on diets.18
35-57% of adolescent girls engage in crash dieting, fasting, self-induced vomiting, diet pills, or laxatives.19
In a college campus survey, 91% of the women admitted to controlling their weight through dieting.
addiction(clinically) - Clinically when it comes to eating disorders this is found in the DSM as “Feeding and Eating Disorders” and it encompasses
PICA (eating nonnutritive, nonfood substances for one month)
Rumination Disorder (regurgitating food, rechewing, spitting out)
Avoidant/Restrictive Food Intake (lack of interest, avoidance with it causing weight loss or deficit or functioning that is not Anorexia)
Anorexia Nervosa (Restriction of energy intake, leading to significantly low weight, intense fear of gaining weight or becoming fat, or persistent behavior that interferes with weight gain even though at a significantly low weight, disturbance in how one thinks of one's body) - can be coded to show someone is experiencing this and Bulimia
Bulimia Nervosa - recurrence of binge eating (eating more in a specific amount of time that is larger than what most individuals would eat, a sense of lack of control over eating, recurring use of behaviors in order to prevent weight such as vomiting, laxatives, diuretics, other medications, etc, binging at least once a week for three months, disturbance in how one thinks of one's body)
Binge eating disorder (the binge part of bulimia without the second half of bulimia)
We will be focusing on the most common thought of diagnosis bulimia and anorexia. They are often lumped together in research for this reason and because of the focus on how one experiences one’s body
PART 1: Terms & Background Info (5-10 minutes)
According to Lauren Muhlheim, We have some records of this going back 323 BC-32 BC and Medival times - a report of a woman starving to death in pursuit of holiness. Deprivation of food was common enough that current authors look back on this period of time and have stated this was ‘holy anorexia”
This has a different motivation behind it but there are those that argue it is the same diagnosis for different reasons
1689 is the first record of ‘nervous consumption by Dr. Richard Morton
1873 was when the term Anorexia Nervosa was coined by Dr. Sir William Gull
Most research has been done by American Hilde Brunch
Bulimia is more recent and was first described by Dr. Gerald Russel in 1979. Purging has been documented as happening in Pharoh times and other ancient cultures but was believed to come from trying to prevent diseases or was even prescribed. The earliest case appears to be in 1903, but we didn’t know it at the time.
Eating disorders have been in the DSM since its inception but were originally labeled psychophysiological gastrointestinal reactions which included ulcers, gastritis, and colitis and we believed the emotional factor was not as important
PART 2: What About Neuroscience (5 minutes)
Why are we looking at THIS TOPIC through this lens?
What unique perspective will Neuroscience show us in regard to this topic?
To cite Giuseppe Riva “Eating Disorders (EDs), as clinicians involved in clinical practice know well, are one of the most resistant and frustrating forms of psychopathology: patients rarely seek treatment voluntarily and their clinical behavior is usually characterized by denial and resistance.”
Like many of our other diagnoses - mental health has been where we started, but we just can not get the results we want without knowing more about what is going on. We need to not only draw circles around things and label them not normal but if we want to fix an actual diagnosis it needs to be what we cited last episode from Strik, Stegmayrer, Walter, and Dierks. If we want to do this we need mental health diagnosis to be reliable and combine valid information about not only what is occurring but why it's occurring so that we can come up with better treatment and prognosis
Why neuroscience? Because mental health has been failing in this diagnosis we need more information so we can do better.
**BREAK**
PART 3: The Science (30-35 minutes)
In their recent reviews, Kaye et al. (2009, 2013) patients with AN and Bulimia Nervosa (BN) share a dysregulation in the anterior ventral striatal pathway (this combined with the amygdala and hippocampus make the mesolimbic dopamine pathways that we discussed in neuro of addiction) that may create a vulnerability for dysregulated appetitive behaviors. If the high level of self-control in individuals with Annenorixa Nervosa —produced by an exaggerated dorsal cognitive circuit functioning—allows them to inhibit appetite, this does not happen in BN patients, based on their limited ability to control their impulses.
According to Johnson (1987), “An image schema is a recurring dynamic pattern of our perceptual interactions and motor programs that gives coherence and structure to our experience” (p. xiv). Image schemas have been suggested as playing a critical developmental role, forming both the basis of early cognitive development and possibly extending to all sensory-motor perceptual modalities (Mandler, 2004, 2012).
What do we mean by image schemas? To understand the Neuroscience of eating disorders, we have to understand our neurological way of making sense of the body
Riva - humans from birth can recognize things - we perceive incoming data and we map the spatial structure and try to understand it. We try to understand the way it moves through space by watching how it moves, and understanding that some things can contain other things.
This is thought by Madler to be a process of the dorsal visual stream
As infants can start to move in their environment they start to understand how they are also a thing that has a trajectory and interacts with other things. Our brains get information about our body in space through this ventral visual stream and medial temporal lobe.
Scientists are starting to come to the same conclusion that we make sense of things twice - once through a schematic or allocentric perspective (objects independent of our body) and once through a perceptual egocentric perspective (location of the objects relative to the body). We need egocentric to be able to grasp things and reach for them and allocentric to understand their size shape and orientation.
Miller et alls study in 2013 using virtual reality found that “place-responsive cells (schematic) active during navigation were reactivated during the subsequent recall of navigation-related objects using language.” which suggests that the way we understand things helps the way we code them in memory and they will reinstate through stimulation to produce a pattern. Riva states “In sum, as suggested by image schema theory, recalling an episodic memory using language involves the recovery of its spatial context”. He states we forget that we are conscious of our body in multiple ways - both as a physical object and subjectively through our brain not related to how we appear. This causes multiple mental representations of the body - location of body parts, sensory information, movement of the body in space, body self-awareness and body representation, public representation, and body image and this is how we make sense of how we move through the world. These are found in different areas of the brain - specifically the posterior parietal cortex (top back of brain), amygdala (mid-brain), insula (midbrain), fusiform (bottom of the brain under the occipital and temporal lobe), occipital (back of brain) and posterior superior temporal sulcus (near the occipital lobe helps with audio and visual stimuli). Rosetti et all state that there are types of interactions between these representations that can be produced specifically that “ body schema and body image are tightly linked”.
Why does all of this matter?
Our experience of the body is linked with self-consciousness - and it's a layered experience- six layers to be exact - We do not experience them separately but there is communication between them and one experience can inform another
This evolves over time. And what happens is we live in a society that is fat phobic and prioritizes bodies of a specific size and that is communicated to us all around causing some of this interaction between our understanding of ourselves to judge that they meet society standards or they don't. More commonly, but not always, women-identified individuals are taught to adopt the objectified view of their bodies but society objectives feminine bodies in a way it doesn’t objective men's bodies, so they are more likely to see their bodies as not having worth (because the standard of beauty is almost completely unobtainable, and by objectifying bodies we have given them a value that is only met if they meet that standard, no other qualifications may apply, and they exist to please others not to please themselves) This influences the brain to adopt an observes perspective on their bodies - they look at themselves as an object that only has value in its physical appearance, which impacts self-objectification. Riva states “Self-objectification is typically manifested as persistent body surveillance or habitual monitoring of the body’s outward appearance and is theorized to lead to a number of negative experiential consequences such as body shame, social physique anxiety, lack of awareness of internal bodily states, and decreased peak motivational states/flow experiences” and argues that individuals with eating disorders are get stuck on one body experience. Conway suggests that we essentially get stuck on one body perspective and when our memory tries to recall it, it usually gets compared to help identify what is actual, idea, or possible and if our current self matches and experiences crossfire. This happens a bit like it does with depression, we get stuck on the negative and can't update the positive. Specifically, our recall of episodic memories of similar experiences feeds into an implicit rather than explicit view of self. Our emotions impact the recall of reality because of how it is translated. So people with eating disorders get locked into a version of their body, the objectified body, that is not getting any updates from perception. From what we see this happens because of structural vulnerabilities involved in this encoding experience, specifically in the precuneus (prefrontal cortex, near the back of your head, helps with the recall of memory and integration of information specifically about the environment) and inferior parietal lobe (prefrontal cortex, slightly deeper but same area, involved with spacial awareness). This damage is thought to be caused by extreme stress, chronic stress, and PTSD.
Just like in depression, this can cause damage to the hippocampus, specifically in that it atrophies, and just like depression and anxiety this damages the HPA axis.
Because - rumination! Berntsen and Rubin state its shame recall, which when we ruminate impacts memory recall, allowing the brain to get stuck.
So you take a person who feels like their body isn’t meeting up, which is most female-identified people, and you add extreme stress or trauma, and this can cause rumination, allowing for memory retrieval to weaken and not function properly, causing the belief of their body to never be updated. According to Riva “If this experience, due to rumination, is repeated many times we can expect two effects: first, the real-time experience of the body is switched off—we are out of our own body; second, the real-time experience of the body is substituted by the contents of the objectified body stored in long-term memory.”
Now remember that this almost always happens in a brain not fully developed.
Gillberg et al state that eating disorders should be considered neurodevelopmental disorders because they rewire it and the central nervous system. Southgate, Tchanturia, and Treasure state “A critical period of brain development occurs in adolescence. The synaptic pruning, elaboration of dendritic arborization, and increased myelination that take place are associated with significant functional refinements of brain systems. Synaptic pruning removes redundant neural connections, maximizing the efficient circuitry of networks shaped by learning and experience. Myelination speeds up neural transmission, thus allowing more rapid communication across connected regions of the brain. These two developmental processes are considered to ‘‘support the collaboration of a widely distributed circuitry”. This allows for connections between your midbrain and your prefrontal cortex which helps with collaborative brain functions. When your brain doesn’t cope with high stress or trauma, it disrupts this process you need to develop properly but with eating disorders, there is the additional impact of poor nutrition and poor nutrition impacts proper hormonal changes. This can cause a decrease of white matter and gray matter, and enlarged cerebrospinal fluid. This can cause a person with an eating disorder to read food cutes as aversive or have lower levels of activation to food cures, specifically According to Uher we see “Activation in the lateral fusiform gyrus and inferior parietal cortex to body image cues was less marked in people with eating disorders and aversion ratings correlated positively with activity in the right medial apical prefrontal cortex”.
Additionally, we see impacts on the reward centers of the brain with bulimia matching substance abuse suggesting an alteration in the brain reward circuits and anorexia having a lower overall reward to both food and exercise - meaning they don’t get the rewards they need to feel positive or successful. We also see a similar response to that neural rewiring we see with gambling and other addictions, where the brain gets stuck in a loop where it doesn’t prioritize other things and impacts risky choices. Lawrence et all state there is “evidence suggests that people with eating disorders have abnormalities in emotional processing and in the appetitive responses that result from reward pathways.”
Body
Feel it on a scale of 1-Diagnosis (1-5)
The body is huge in this one, as we covered, specifically that the brain has rewired due to stress, trauma, etc., and caused rumination, which causes an impact on our memories, which helps the brain get stuck as it does in depression. What makes this different is that rumination is focused on the body and that rumination can cause one version of our body to not get updated the way it's supposed to - it's stuck. Added to the chemical dependency high of I must do this thing above all others.
Warning signs are (to name a few) over focus of the body, especially early. Spending a lot of time in the bathroom, weight gain, or weight loss that is not in line with development, noticing avoiding food or noticing food disappearing.
We want to learn WHY we do what we do as humans, and we’ve looked to the brain for explanations…
**BREAK**
PART 4: TAKEAWAYS (10-15 minutes)
Takeaways are largely focused on treatment because this is one of the hardest diagnoses to recover from and it's one of the deadliest - so we need to start with the most important part, which is keeping people safe.
Starting with the beginning - we need to focus a lot more on:
Attachment! Southgate, Tchanturia, and Treasure state “Attachment behaviors within and outside of the session need to be at the center of treatment.” As we recall from our episode in season 1, the neuroscience of relationships, the way we make sense of ourselves, our world, our bodies, and our relationships stems from those first few years of life. Attachment impacts us more than we realize, want to admit, or talk about. It is our fundamental building block and if we think of eating disorders more as developmental disorders, this makes a ton of sense. They also state “emotional functioning another aim of treatment is to maximize emotional ‘‘intelligence’’ so that the response to the environment is optimized. In the case of AN the content of emotional coaching focuses on accepting and reflecting on emotions rather than using displacement or avoidance. A warm supportive, empathetic relationship is the bedrock upon which emotional issues can be built. Obsessive-compulsive personality traits which include doubt, indecision, meticulousness, intolerance of uncertainty, and perfectionism, can interfere with the process of therapy in many ways. The role of therapy is to help people learn to have an approach to life that uses strengths in all suites rather than a rather skewed approach in which they can only play their dominant hand.” This is an easy thing to say and a harder thing to do. Because often attachment issues can cause a lot of damage to trust and being able to create this kind of relationship, it’s going to take a lot more effort and focus than previously thought.
And moving to the future.
VR! This was cool for me to find because I wished I had the ability to get an NIH grant for VR and mental health since 5G came out! Riva states “The convergence between technology and medicine is providing new tools and methods for behavioral healthcare.” Specifically citing what VR could do because this allows the clinician to provide an IRL experience without the downsides that current exposure treatments have - because this is a safe, controlled environment. So patients can be emotionally present without being distracted, and it has the additional aspect of allowing for “an advanced imaginal system: an experiential form of imagery that is as effective as reality in inducing emotional responses.” This means we could use this for things like phantom limbs, and a lot of other therapies around changing how we perceive our body to work through things like eating disorders, gender dysphoria, and more. To quote Riva “In a VR experiment, Burgess and colleagues examined the neural systems involved in the retrieval of the spatial context of an event. The measured activation showed the buffering of the location of scene elements in successively translated frames of reference (allocentric, body-centered, head-centered) between the parahippocampus and the precuneus. All these data suggest that it may be possible to use VR to induce a controlled sensory rearrangement that facilitates an update of the locked allocentric representation of the body”.
SSRIs! I did not specifically find any research citing this exactly, but we know from the research we reviewed that eating disorders deal with rumination and that rumination is causing damage to the hippocampus. We know from the neuroscience of depression that a real benefit to SSRIs besides the increase of serotonin, is that it helps decrease the damage to the hippocampus, which is vital in long-term recovery.
Additionally, I would state that a long-term takeaway is changing how we react to bodies. It needs to be a societal change, and it's a big ask but I think we are taking big steps toward it. I have heard people argue about the damage of social media, and I agree that with a developing mind, we need to change our approach to this. But I will also say I’ve seen a lot of social media that can also go the other way - that is critiquing and educating how we respond to feminine bodies and the need to stop objectifying them. I've also seen a ton of education on reducing fat phobia and the social movement to decrease this. And it's had an impact - finally after decades of knowing how inaccurate, racist, and problematic the BMI’s we finally have the AMA taking action to not use it.
We also need to work to change what we see as beautiful. So as odd as it is I will leave you with two of my favorite quotes from science fantasy author Jim Hines “I’ve never met anyone who wasn’t beautiful. People have simply forgotten how to see.” And “The more we narrow the definition of beauty, the more beauty we shut out of our lives”. I challenge you, with the reminder that neuroplasticity can absolutely 100% change how we respond to things - add more beauty to your life, appreciate bodies of all kinds, and start challenging yourself on what is needed to be beautiful.
If you've never had, or never known someone with an eating disorder, you might not feel like this episode applies to you. We promise you, it does, it applies to all of us.
Because when it comes to eating disorders, it just feels so simple. Why can't this person just start (or stop) eating? But what if we told you it has very little to do with eating, and everything to do with how the brain sees the body?
In this month's deep-dive episode, Laine walks us through the science behind the deadliest diagnosis in mental health. Using findings from scientists Riva, Southgate, Tchanturia, Treasure, Stanghellini, Ballerini, and Mancini we discuss things like:
How the brain understands the body
How this can and will rewire the brain
Why is it so hard to stop
A major takeaway to not only help stop unnecessary death but also change society and create more beauty and self-empowerment in our lives
A small disclaimer: We will be connecting the research to understanding eating disorders to what we learned in both the Neuroscience of Depression and the Neuroscience of Addiction if you want to check those out ahead of time.
If you want to know more ways to be part of our Brain Blown Community, head to www.patreon.com/brainblownpodcast to learn about our offers! If you have any topics you'd be interested in learning more about, please feel free to send us an email at info@brainblownpodcast.com!
We'd love to hear from you.
REFERENCES
Giuseppe Riva, Ph.D. -- Out of my real body: Cognitive neuroscience meets eating disorders
Laura Southgate, Kate Tchanturia, and Janet Treasure --Building a model of the etiology of eating disorders by translating experimental neuroscience into clinical practice
Giuseppe Riva, Ph.D. -- The Key to Unlocking the Virtual Body: Virtual Reality in the Treatment of Obesity and Eating Disorders
Giovanni Stanghellini, Massimo Ballerini, and Milena Mancini -- The Optical-Coenaesthetic Disproportion Hypothesis of Feeding and Eating Disorders in the Light of Neuroscience
