Eating disorders and borderline personality frequently occur together, but until recently, very little was known about the relationship between borderline personality disorder (BPD) and eating disorder conditions. Recent research, however, is revealing how often BPD and eating disorders co-occur, why they may be related and how to treat these two types of disorders when they do co-occur.
What are Eating Disorders?
Eating disorders are psychiatric disorders characterized by severe problems with eating behavior. The Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV), the official guidebook to the diagnosis of psychiatric disorders used by mental health providers, recognizes two specific types of eating disorders: anorexia nervosa and bulimia nervosa.
The central feature of anorexia nervosa is a refusal to maintain a minimally normal body weight (body weight greater than 85% of that expected for the individual’s age and height). In contrast, the central feature of bulimia nervosa is the presence of binge eating, followed by behaviors that are attempts to compensate for the binge eating, such as self-induced vomiting, overuse of laxatives, excessive exercise, etc).
There can be some overlap in symptoms between these two disorders. For example, someone may engage in binge eating and purging, but also be unwilling to maintain a normal body weight. In this case, the individual may be diagnosed with anorexia nervosa, binge-eating/purging.
Eating Disorders and Borderline Personality Prevalence
People with borderline personality disorder have a greater prevalence of eating disorders than people in the general population. For example, a widely cited study by Dr. Mary Zanarini and her colleagues at McLean Hospital found that 53.8% of patients with BPD also met criteria for an eating disorder (compared to 24.6% of patients with other personality disorders). In this study, 21.7% of patients with BPD met criteria for anorexia nervosa and 24.1% for bulimia nervosa.
Of course, this is not to say that people with eating disorders necessarily have borderline personality disorder. In fact, the overwhelming majority of people with eating disorders do not have BPD. It appears that the rate of BPD in people with eating disorders is somewhat elevated when compared to the general population (about 6 to 11%, compared to 2 to 4% in the general population). Some eating disorders, though, are associated with having a higher risk of BPD than others. For example, one study found that people with bulimia nervosa, purging type may be at a greater risk for BPD (with about 11% meeting BPD criteria) than people with anorexia nervosa, binge-eating/purging type (with about 4% meeting BPD criteria).
How Are Eating Disorders and Borderline Personality Related?
Why do people with BPD seem to have eating disorders at a greater rate than people in the general population? Experts have noted that one possible explanation is that BPD and eating disorders (particularly bulimia nervosa) share a common risk factor: both are associated with histories of childhood trauma, such as physical, sexual and emotional abuse). It could be that having a history of childhood trauma puts one at greater risk for both BPD and eating disorders.
In addition, some experts have suggested that it may be that the symptoms of BPD put one at risk for developing an eating disorder. For example, chronic impulsivity and urges to self-harm may lead one to engage in problematic eating behavior, which may over time rise to the level of an eating disorder. It may also be that engaging in eating disordered behavior may lead to experiences of stress (e.g., intense shame, hospitalization, family disruption), that may trigger BPD in someone with a genetic vulnerability for the disorder.
Treatment for Eating Disorders and Borderline Personality
What can be done about BPD and co-occurring eating disorders? The good news is that there are effective treatments available for both types of conditions. While some studies have indicated that people with BPD do not respond as well to eating disorder treatment, other studies have found no differences in treatment response between people with eating disorders with or without BPD.
Which problem should be treated first? It may be that both the eating disorder and the BPD symptoms can be treated at the same time, but this may be decided on a case-by-case basis. For example, some people have eating disorder symptoms that are so severe they are immediately life-threatening. In this case, hospitalization for the eating disorder symptoms may be necessary before treatment for the BPD symptoms can begin. Alternatively, in someone with very severe BPD symptoms that are either life-threatening or threaten to reduce their ability to engage in treatment, the BPD symptoms may be treated first.
If you think you (or a loved one) may have BPD and/or an eating disorder, the first step is to find a mental health provider who can make the right diagnosis. For more information on finding treatment, check out these articles:
Godt K. “Personality Disorders in 545 Patients With Eating Disorders.” European Eating Disorders Review. 16:94-99, 2008.
Pope HG, Hudson JI. “Are Eating Disorders Associated With Borderline Personality Disorder? A Critical Review.” International Journal of Eating Disorders. 8:1-9, 1989.
Sansone RA, Sansone LA. “Childhood Trauma, Borderline Personality, and Eating Disorders: A Developmental Cascade.” Eating Disorders: The Journal of Treatment & Prevention. 15:333-346, 2007.
Zanarini MC, Frankenburg FR, Hennen J, Reich DB, Silk KR. “Axis I Comorbidity in Patients with Borderline Personality Disorder: 6-Year Follow-Up and Prediction of Time to Remission.” American Journal of Psychiatry. 161:2108-2114, 2004.
Zeeck A, Birindelli E, Sandholz A, Joos A, Herzog T, Hartmann A. “Symptom Severity and Treatment Course of Bulimic Patients With and Without a Borderline Personality Disorder.” European Eating Disorders Review. 15(6):430-43, 2007.