Anxiety is a general term which encompasses several disorders that can result in nervousness, apprehension, fear, and worrying. Anxiety is a normal part of life and an emotion that most people will experience at some point in response to stressors; however, when it takes an extreme turn or is objectively disproportionate to the situation, it may meet the criteria for an anxiety disorder. Sadly, anxiety commonly coexists with other conditions and eating disorders are no exception.
Eating disorders are a term used to describe people who have a preoccupation with food and who restrict their intake in some shape or form (either through amount or type of food) which often has serious health consequences in both the short and long-term. The most commonly known disorders are anorexia (where people restrict food intake, exercise excessively and purge through the use of laxatives or vomiting in order to reduce their body weight) and bulimia where people typically have “normal” body weight but will “binge” on excessive amounts of food and subsequently purge owing to fear of the consequences of retaining it. There are other eating disorders such as avoidant or restrictive food intake (ARFI), orthorexia (an obsession with eating healthily) and binge eating disorder (bingeing but without purging).
How common is it to have both anxiety and an eating disorder?
There is also an association between childhood anxiety and subsequent severity of eating disorder as an adult as measured by body mass index (BMI): one study found that early childhood anxiety, caloric restriction, qualitative food item restriction, excessive exercise, and low BMI were all strongly associated. Childhood personality traits, such as perfectionism, following rules and concerns around mistake-making were more common in those who subsequently developed an eating disorder than in those who did not. Interestingly, another study found that heightened social anxiety could predict the drive towards being thin as would be seen in anorexia, whilst degrees of social comparison was predictive of bulimic attitudes.
OCD appears to be the most common anxiety disorder found to co-exist with eating disorders: two thirds of percent of patients with anorexia nervosa and a third of patients with bulimia nervosa have a co-existing diagnosis of OCD. Another condition found quite commonly is post-traumatic stress disorder (PTSD): approximately one in four people with an eating disorder has been found to have symptoms of PTSD.
What mechanisms are at play in eating disorders that might influence mood?
When those with anorexia eat, they typically experience increases in the neurotransmitters serotonin and dopamine, both of which have an affect on mood. When these neurotransmitters are elevated, this can increase feelings of anxiety and tension. In bulimia, the opposite reaction might take place: instead of tension increasing, many find bingeing reduces stress and improves their mood; this therefore reinforces the behavior. The usual response to fear and stress is loss of appetite, owing to physiological changes in the fight or flight response; however curiously, anxiety is the most commonly experienced emotion obese people with a binge-eating disorder experience prior to bingeing.
The role of anxiety in eating disorders typically starts early in life. Many anxiety disorders have some sort of presence in childhood and therefore typically predate the onset of the eating disorder (usually late adolescence or early adulthood) although increasingly the age of eating disorder onset is lowering. Research has also found that children who are obese and overeat have problems with stress, and typically struggle to manage tension and worry; they learn an association between reduced anxiety and overeating as eating is an area where they cultivate a sense of control.
There are a variety of reasons that someone might develop Avoidant or Restrictive Food Intake (ARFID). Often sensory issues such as taste or texture of foods are the cause; or sometimes conditions such as emetophobia (fear of vomiting) might be involved. Sometimes someone may have had a distressing experience with food, such as choking – which can generate fear and anxiety in the context of food and lead them to avoid it. In some cases, the person may just not be interested in eating or feel hunger in the same way. Those on the autistic spectrum (ASD) or attention-deficit/hyperactivity disorder, as well as those with anxiety, may be more likely to develop ARFID and it is common for women with high-functioning ASD to be misdiagnosed with an eating disorder before later being identified as on the spectrum.
Some argue that popular diets (such as veganism) can also be a form of eating disorder: for example, vegans often become severely deficient in Vitamin B12 as well as other vitamins and minerals and this can cause significant health problems. One study found that vegetarian college women were more likely to display disordered eating attitudes and behaviors than non-vegetarians. Likewise, the adoption of a vegetarian dietary style can be, for some, an attempt to mask their dieting behavior from others, according to research. Restrictive diets such as veganism or vegetarianism could be argued to be socially acceptable eating disorders: people can be open about their restrictive intake, demand different food to others, perhaps even take their own food with them etc. Current trends for dairy-free and gluten-free could also be seen to fall into this category. Some term the current trends towards restrictive diets as Orthorexia, which is used to describe where people have an obsession with eating healthily - research has found that vegans and vegetarians score higher in orthorexic eating behaviors than those who are omnivorous.
Whilst the consensus is that the anxiety typically predates the eating disorder, in other cases the depression and anxiety may well result from the eating disorder itself. It has been suggested that reduced availability of tryptophan (TRP) resulting from insufficient dietary intake can inhibit serotonin activity and perhaps trigger co-morbid symptoms. Interestingly, women tend to have lower levels of TRP than men and are more prone to both eating disorders and anxiety.
Treatment of eating disorders and anxiety
Eating disorders are caused by a complex interaction of genetic, biological, behavioral, psychological, and social factors; as are anxiety disorders. As there appears to be an increased likelihood of having one where you have the other, it is essential that anxiety is treated in conjunction with eating disorder treatment. Shared underlying issues are often at play in both and so addressing both can support healing.
Comprehensive treatment approaches for an individual suffering from both anxiety and an eating disorder are
- Cognitive-behavioral therapy (CBT)
- Acceptance and commitment therapy
- Dialectical behavioral therapy
- Psychodynamic psychotherapies
- User support groups
There are some medications that can be helpful in managing anxiety and separating feeling-associations from food; although traditional anti-depressant medications have more of an evidence base to support them in bulimia than in anorexia for the eating disorder alone.
Where anxiety and eating disorders are co-morbid it is a challenge, and, as with all co-existing disorders it is often a “chicken-and-egg” debate; but unfortunately, often the inter-relationships and interdependency of conditions is often too complex to quantify. Both eating and anxiety disorders appear to have shared risk factors (such as difficulties with emotional regulation, family history etc.) and appear to be on the increase in society in general therefore it is an issue worthy of attention.