This is part two of the series Eating Disorders 101: Binge Eating, Anorexia Nervosa and Bulimia Nervosa. Read part one here.
Eating disorders almost always have underlying causes, and successfully treating an eating disorder requires addressing them. Genetic, psychological, biological, and socio-cultural risk factors can contribute to the development of an eating disorder.
Although there is some evidence that eating disorders may run in a family, the genetic influence is thought to be a complicated interaction between many different genes that govern a variety of biological processes.
Researchers have identified a number of personality traits that are common among people who have bulimia and anorexia:
Impulsivity, particularly with bulimia
Inflexibility and excessive persistence, particularly with anorexia
According to the American Psychological Association, a number of complex biological factors may contribute to eating disorders.1
People with anorexia appear to have heightened activity in the brain region associated with habitual behaviors.
People with anorexia and bulimia may have structural and chemical abnormalities in the brain region responsible for sending a signal to stop eating.
Increased or decreased activity of certain neurotransmitters may contribute to disordered eating. These neurotransmitters include dopamine, which is involved in the reward and motivational aspects of eating, and serotonin, which plays a role in mood and impulse regulation.
Medications can help regulate brain function to reduce urges and promote healthier ways of thinking and behaving.
Girls and women have impossible beauty standards to live up to, and for many, obtaining or maintaining the “perfect” body is a major, constant struggle. Fear of weight gain, fat-shaming, teasing, and other forms of discrimination and prejudice can contribute to disordered eating, as can dysfunctional personal relationships.
Eating Disorders and Sexual Trauma
A study published in the journal Child Abuse & Neglect found a significant association between a history of trauma and eating disorders.2 An estimated 30 percent of people who have an eating disorder also have a history of sexual trauma.3 Research shows that more than two-thirds of sexual assault and rape victims develop moderate to severe stress reactions, which may include nightmares, insomnia, flashbacks, unwanted thoughts, and feelings of intense anger. These are often diagnosed as post-traumatic stress disorder.
Some sexual abuse survivors may develop disordered eating as a way to cope with traumatic memories and symptoms of PTSD. For others, an eating disorder may develop as the result of intense body shame. Some disordered eating behaviors, such as starving the body, may be a coping mechanism similar to other self-harming behaviors like cutting.
Eating Disorders and Substance Abuse
According to the Substance Abuse and Mental Health Services Administration, eating disorders and substance use disorders commonly co-occur. Research shows that 27 percent of people with anorexia, 36.8 percent of people with bulimia, and 23.3 percent of people with binge eating disorder also have a co-occurring substance use disorder.
Treating co-occurring eating and substance use disorders at the same time, each in the context of the other, is essential for successful long-term recovery from both disorders.
Eating Disorders and Co-Occurring Mental Illnesses
Mental illnesses—particularly anxiety—also commonly co-occur with eating disorders. According to SAMHSA, an estimated 48 percent of people with anorexia, 65 percent of people with binge eating disorder and 81 percent of people with bulimia have a co-occurring anxiety disorder.
Anorexia is commonly associated with major depressive disorder and narcissistic personality disorder, and bulimia is often associated with borderline personality disorder. Both anorexia and bulimia are associated with bipolar II disorder.
Integrated treatment for a mental disorder that co-occurs with an eating disorder offers the best treatment outcomes.