The cause of bulimia nervosa is multifactorial, and several different risks and predispositions may be involved in causing an individual to develop the disorder.
However, the exact cause is not known and it is unclear why some people with few risk factors are affected, yet others with more risk factors for the disorder are not affected. Nonetheless, the following causes are believed to be associated with bulimia nervosa.
Body Image and Self-Esteem
Self-esteem and the view that the individual has of their body weight and appearance is a strong contributing factor in causing bulimia nervosa.
In modern western society, there is a strong emphasis on the physical beauty of women, which is usually portrayed by mainstream media as unrealistically thin. This increases the potential of women to feel inadequate or unattractive in contrast to the projected ideals.
Psychological concerns about body weight and image is a major contributing factor for bulimia nervosa. In particular, difficulty managing emotions and pressures from the surrounding environment is a common link between many individuals that suffer from the condition.
For many patients, eating is a way to release strong emotions and, as a result, the urge to eat is strongest when they are feeling upset, angry or stressed. Additionally, patients that suffer from anxiety or depression are at a higher risk of developing an eating disorder.
Individuals who have been subjected to childhood or sexual abuse are also more likely to be affected by bulimia nervosa. This is thought to have an impact on their thought patterns and psychology, which can lead to unhealthy ways of dealing with environmental factors and stressors.
Involvement in some activities or occupations that place a high importance on the physical beauty of an individual may also contribute to the cause of bulimia. For example, ballet dancers, models, actors, gymnasts and other athletes have a higher level or pressure to maintain a certain physical appearance, which can cause them to feel stressed or anxious about their diet.
Additionally, major changes to the lifestyle or certain events can also increase levels or stress and the risk of developing an eating disorder such as bulimia nervosa. For example, individuals are more likely to be affected or have a relapse after a significant family event, a relationship breakdown, or relocating for study or a new job.
A familial link appears to be evident in many cases of bulimia nervosa and individuals with a family history of the disorder or other similar conditions (e.g. other eating disorders, mental health conditions, substance abuse) are four times more likely to be affected than those who do not. However, it is not clear if this is caused by an inherited genetic mutation or acquired behaviors from the living environment.
Changes in the levels of hormones in the body can also play a role in the pathology of bulimia nervosa.
Adolescents going through hormonal changes during puberty are most likely to be affected, which is thought to arise from a combination of environmental stresses and hormones.
Additionally, abnormal concentration of neurotransmitters in the brain (e.g. serotonin, noradrenaline and dopamine) and hormones such as estrogen are present in individuals with the condition. There is a theory that this is linked to causing the condition, although it is yet to be supported by scientific evidence.