Like most mental health conditions, there isn’t one consistent reason people develop an eating disorder, like anorexia; instead, it is caused and maintained by the interaction of multiple biological, psychological and sociocultural factors, whose relative contribution to the illness varies from individual to individual.
Understanding the neurobiological causes of anorexia is complicated by the fact that many of the brain abnormalities seen in people with anorexia can both cause and effect the undernutrition.
Once a person is very underweight, biological factors intensify other aspects of the illness (e.g., fear of weight gain and distorted body image), maintaining the condition in a vicious cycle and complicating recovery.
Genetics – Studies suggest there is a hereditary component to anorexia and you are much more likely to have the illness if someone in your family also has anorexia. However, this does not necessarily indicate the existence of an “anorexia gene.” Instead, genetics influence biological characteristics that play a role in how we respond to challenging life events via:
Neurochemistry – A number of neurotransmitters (chemical “messengers” that are responsible for communication within and between the various parts of the brain) frequently show irregularities in people with anorexia.
The most studied of these are serotonin and norepinephrine, which play an important role in the regulation of both emotions and appetite. Serotonin and norepinephrine are also heavily linked to depression and anxiety and may explain why such a high proportion of people with anorexia also have these conditions.
Furthermore, weight loss in and of itself can cause neurochemical imbalances, suggesting why people with anorexia are particularly susceptible to low mood and heightened anxiety and obsessiveness (regardless of whether they were depressed or anxious prior to developing an eating disorder) and often find it increasingly difficult to discern hunger cues. These additional challenges may in turn strengthen an eating disorder and complicate a person’s recovery.
Neurophysiology - Brain shrinkage, reduced metabolism and impaired neural blood flow have all been observed in people with anorexia. These abnormalities may at least partially account for the problems with memory, attention, flexible thinking, problem solving and decision making experienced by many people with the illness.
There has been a particular focus in recent eating disorder research on a brain structure called the insula. The insula is responsible for tasks such emotion regulation, managing anxiety and giving feedback on the “internal state” of our bodies1, and its abnormal functioning may help explain the distorted body image, reluctance to change behaviours and failure to respond “the normal way” to hunger2 seen in many people with eating disorders.
There is no single personality profile for people who develop anorexia. However, decades of research have identified a cluster of personality features that are common in people with the condition:
Hyper-awareness of potential threat and harm avoidance (e.g., “a better safe than sorry” approach to new situations)
Preference for order and discomfort with change
Desire for others’ approval
Taken together, these traits can make people vulnerable to low self-esteem, anxiety and low mood, impede identity development and make adapting to the increasing demands and complications brought on by the developmental transitions to adolescence and adulthood particularly stressful. These secondary factors can all play a role in the development of an eating disorder.
The sensitive characters often seen in people with eating disorders should not be regarded as an inherent weakness. The Maudsley Trust have coined the term “orchids” to describe the temperament of many of those with anorexia – individuals who are naturally more fragile and can be “damaged” more easily by environmental factors, but who, given the right conditions, will thrive and achieve great things3.
In addition to the above characteristics, people with the binge/purge subtype of anorexia may also present with a variety of personality features frequently seen in people with bulimia, many of which are also risk factors for mental health problems more broadly:
Fluctuating or limited sense of self
People with these characteristics may experience:
‘High’ highs and ‘low lows’
Difficulty controlling their emotions and behaviours
Struggle with figuring out “who they are”
Seek out thrilling and sometimes dangerous experiences
Have an erratic approach to coping with stress
Be prone to intense feelings of anxiety, sadness and shame.
Developmental influences In the 1970s and 1980s several theories were advanced emphasising the role of certain patterns of family dynamics in the development and maintenance of anorexia.
The following family styles were identified as possibly leading children to either deny or assert their needs in unhelpful ways, including adapting their eating behaviours:
Limited interpersonal boundaries
Difficulties with separation and autonomy
Other research has examined whether parents’ own problematic attitudes towards eating, shape and weight may lead to similar concerns in children and hence contribute to eating disorders. Although it appears that children’s beliefs and behaviours around food are influenced by their families, the research suggests that such influences alone are insufficient to explain the development of full-syndrome anorexia.
Traumatic experiences Research has shown that certain difficult life experiences can increase the risk of someone developing anorexia. These might include growing up in a neglectful or hypercritical home environment, bullying by peers or traumatic experiences such as physical or sexual abuse.
Body dissatisfaction and body image distortions It has become clear that emotional states (which may be experienced as “feeling fat” in response to distress) may be at least as important in driving body dissatisfaction as perceptual distortions (actually seeing oneself as fat).
People with anorexia also frequently have impaired interoceptive awareness (the ability to feel and interpret internal states such as hunger, thirst, tiredness and pain), complicating how they experience their bodies and disturbing their appetite.
Recognition of the role of brain structures such as the insula in regulating our experience of our physical appearance, internal sensations and emotions, and observation that these parts of the brain show abnormalities in people with anorexia, suggest that biological, psychological and sociocultural influences converge to inform body dissatisfaction, body image and eating attitudes.
It is also important to note that a minority of people with anorexia do not report body dissatisfaction at all and feel very self-conscious about their emaciated appearance but are nevertheless very distressed at the prospect of eating more and putting on weight.
I was handled with extreme care and attention, ever step of the way. The therapy I have had has been life changing.
Sociocultural factors of anorexia
Cultural values in Western, industrialised countries championing thinness in women and equating slimness with values such as beauty, success and self-control have long been seen as contributing to eating disorder development.
The rise in eating disorders that accompanied the transition from the voluptuous feminine ideal of the 1950s to the ultra-slim model look since the 1960s appears to support this view. However, past reporting suggesting anorexia was largely confined to affluent, urban, female populations in Western societies has proved inaccurate: eating disorders are now known to occur, albeit at lower rates in some groups than others, across cultures, races and sexes.
The misconception of vanity - the unhelpful stereotyping of anorexia as a disorder driven by vanity has likewise been dispelled. Instead, as with other “causes” of anorexia, social messaging around thinness is now seen as one factor that may—or may not—contribute to some degree to the development of a given person’s eating disorder.
Sociocultural factors may play a role not only in the development of anorexia but also how it manifests. For example, research in Asia has reported that many eating disorder sufferers there cite fear of gastric bloating rather than a fear of becoming fat as the primary reason they are scared to gain weight This implies that fear of becoming fat may be just one culturally-specific expression of the disorder, informed by Western messaging around health and beauty.
For all of us, a key life task is finding a way to be, pursue goals and respond to challenges that fits our unique psychology and circumstances. For those whose biology, psychology and context made them vulnerable to an eating disorder, recovery is then not about becoming a different person but rather identifying and pursing a course that plays to their strengths, protects against their vulnerabilities and those created by their environment, and thus ultimately allows them to thrive.
Dr Charlie Baily is a Clinical Psychologist currently working in the private sector. He has a PhD in Clinical Psychology and is a member of The British Psychological Society and Health and Care Professions Council.
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