The cause of bulimia nervosa is unknown; most researchers suspect no single cause exists. Instead, current research suggests bulimia results from a combination of factors: social pressures, psychological disorders, and biological causes such as serotonin imbalances.
Risk Factors for Bulimia Nervosa
A number of risk factors increase the chance of developing bulimia nervosa. None of these factors can be considered causes of the eating disorder, but are common among bulimics. Risk factors include:
- age between ten and thirty
- Caucasian ethnicity
- female gender
- heavy academic pressure in school
- high intelligence
- history of substance abuse
- perfectionist personality traits
- sexual promiscuity
- tendency to over achieve
- victim of sexual or child abuse.
Bulimia nervosa rates are higher in homosexual males than in heterosexual males, leading some researchers to speculate on possible connections between gender identity, body image, and eating disorders.
Social Pressure and Body Image
Social attitudes towards body image has been linked to the development of eating disorders. Western industrialized societies, where incidence rates of bulimia and anorexia are highest, equate thinness with attractiveness, success, and self-control. Being overweight is seen as a personal failure, and obesity is simultaneously marginalized and mocked.
Social attitudes towards weight loss and weight gain have a profound effect on a person’s body image. In America, for instance, eighty percent of women report dissatisfaction with their weight, and girls as young as nine report attempts at weight loss. The western ideal of the “perfect” female body is both taller and thinner than the average woman’s body shape.
In theory, social attitudes towards beauty and weight loss produce unrealistic body images in people who develop bulimia nervosa. A bulimic’s ideal body image makes her believe she is heavier than she actually is. While dieting to achieve her unrealistic and distorted body image, the person begins to adopt bulimic practices in the hopes of losing weight. Eventually, these habits develop into full-fledged bulimia nervosa.
Social attitudes towards body image and losing weight, however, cannot be seen as the sole cause of bulimia. After all, the entire population is bombarded by social messages that equate thinness and losing weight equates with success and happiness. However, only one to three percent of the overall population develop bulimia. While social pressure undoubtedly influences bulimia nervosa, other factors must also contribute to the eating disorder.
Family Life and Weight Perceptions
Studies have noted higher than normal rates of substance abuse in families of bulimics, especially alcohol abuse. Rates of obesity, depression, and mood disorders are also higher.
People with bulimia nervosa often come from family environments that subjected them to physical, emotional, or sexual abuse. Other bulimics reported coming fromfamilies where weight, losing weight, and body image were considered important. Losing weight was met with approval, and weight gain was treated with concern or scorn.
Families of bulimics also tend to have high rates of perfectionist, high-achieving behavior. Some bulimics report that their parents used “comfort food” to manage stress and negative emotions rather than emotional or other support.
As with social influences on body image, however, not all bulimics report family abuse or families that placed abnormal significance on losing or gaining weight. It has been suggested that family dynamics and histories of abuse provide a fertile ground for the development of bulimia nervosa in people with predispositions towards the eating disorder. Both mental and physical factors have been suggested as predisposing factors.
Mental Health and Bulimia Nervosa
Anxiety disorders and depression commonly coexist with bulimia nervosa, and usually center on weight gain, body image, and losing weight. It is unclear whether anxiety and depression cause bulimia anorexia and a distorted body image, or whether preexisting misconceptions about body image causes bulimia, which in turn triggers depression and anxiety.
Patients suffering from bulimia nervosa often have difficulties with impulse control, which may explain the uncontrollable nature of binge eating. Low self-esteem, feelings of helplessness, low self-worth, and fears of weight gain are also common.
A study by the National Institute of Mental Health revealed that many people with bulimia nervosa exhibit obsessive behavior as severe as diagnosed obsessive compulsive disorder (OCD). OCD is often associated with unusual eating behaviors.
Serotonin Imbalances: A Physical Cause of Bulimia?
The fact that bulimia nervosa, depression, and obsessive compulsive disorder often occur together suggests a common cause. All three conditions have been linked to imbalances in the brain chemical serotonin.
Serotonin is a neurotransmitter used in nerve cell communication within the brain. Serotonin plays an important role in controlling anxiety levels, depression, anxiety, and impulse control. Perceptions of hunger and appetite are also influenced by serotonin.
A serotonin/bulimia nervosa study by Dr. Walter Kaye of the University of Pittsburgh suggests serotonin imbalances play a role in bulimia. Kaye compared levels of the brain chemicals serotonin, dopamine, and norepinephrine in recovered bulimics with levels of the same brain chemicals in people who never experienced bulimia behavior.
Levels of dopamine and norepinephrine were the same for both groups. However, serotonin levels in recovered bulimics were abnormal. Kaye notes that the abnormal serotonin levels were accompanied by a higher rate of negative moods, perfectionism, and exactness â€” all personality traits associated with bulimia.
Low levels of serotonin result in depression. Binge eating may increase serotonin levels, relieving depression and producing feelings of calmness and well being. However, binge eating may raise serotonin levels too high, causing intense anxiety and agitation. The bulimic associates this anxiety with food consumption, and possible weight gain. To prevent weight gain, the bulimic purges. Purging lowers serotonin levels, causing depression symptoms and restarting the cycle of bulimia behavior.
Tempting though it is to believe serotonin imbalances cause bulimia nervosa, serotonin does not account for all bulimia cases. Some people with bulimia nervosa have no evidence of a serotonin imbalance, and many people with serotonin imbalances do not suffer from bulimia.
Serotonin is, however, known to affect a wide range of mental disorders, including anorexia nervosa, attention deficit hyperactivity disorder, anxiety, bipolar disorder, borderline personality disorder, depression and OCD, all of which have been linked to bulimia.
Bulimia nervosa appears to have a genetic component, and does seem to run in families. Serotonin imbalances can also be hereditary.
Serotonin imbalances, then, may predispose a person to bulimia nervosa. Perhaps when combined with social pressures about losing weight, body image, family history, and psychological factors, serotonin imbalances may trigger bulimia. Different factors may cause serotonin imbalances to trigger different psychological disorders, so while one person develops bulimia, a second develops depression, and a third experiences no effects at all.