Numerous studies have been conducted in order to determine the degree and nature of comorbidity of an eating disorder among those with borderline personality disorder. In an experiment conducted by Johnson, Tobin, and Enright (1989), 94 patients with eating disorders were evaluated for other psychiatric problems. A quarter of them were diagnosable with borderline personality disorder. Borderline patients were found to be more likely to abuse laxatives as a means of maintaining the weight they believed was appropriate, but other than that, the disordered eating habits of borderlines and non-borderlines were similar among those who had eating disorders.
While no significant differences obtained, apart from the use of laxatives as a means of purging, among borderline and non-borderline individuals with eating disorders, the two had markedly different attitudes when it came to eating. Borderlines were more likely to exhibit serious dissatisfaction with their body, alexithymia and a greater desire to be skinny.
Findings in an experiment conducted by Steiger and Stotland (1995) were similar except they did not find a marked discrepancy in the binging and purging patterns between borderlines and non-borderlines(Caldwell). Skodol, Oldham, Hyler et al (I 993) found that bulimics were more likely to suffer from borderline personality disorder whereas anorexics were more likely to suffer from avoidant personality disorder. Herzog, Martin, Lavod, et al (1992) found in an experiment with 210 participants with eating disorders that 9 percent of the patients qualified for a diagnosis of borderline personality disorder(Caldwell).
The experiment was similar to the previous experiments in that borderline personality disorder was not at all associated with anorexia(Caldwell). Those with personality disorders exhibited a high degree of comorbidity when it came to Axis 1 disorders and suicide attempts. Their disordered eating patterns also tended to last longer. As with the other experiments, bulimia was highly associated with borderline personality disorder and that bulimics also had the earliest onset of the disorder and that the presence of a personality disorder may predispose an individual to early onset. Wonderlich, Fullerton, Swift, et al (1994) found, unsurprisingly, that patients with both an eating disorder and borderline personality disorder had more severe eating disorder problems, but did not differ in other respects from their non-borderline counterparts(Caldwell).
Like several of the previous experiments the researchers in this case also noted that subjects with personality disorders did not differ from those without personality disorders in the amount of symptomatic changes, in their patterns of eating , overtime(Caldwell). Yet for obvious reasons their psychopathology generally remained more severe in the cases of borderline personality disorder(Caldwell).
In general, it is taken for granted that eating disorders are much more prevalent among those with borderline personality disorder than those without the disorder, with 25 percent of anorexics exhibiting the symptoms of borderline personality disorder and those with bulimia possessing a 28 percent prevalence rate. (“Borderline Personality Disorder And Eating Disorders”). Among those without an eating disorder, 5 to 10 percent of the population suffers from a personality disorder.
It is interesting to note that the prevalence of this sort of comorbidity is much more common among women than men with borderline personality disorder, who are more likely to exhibit a substance abuse disorder than an ating disorder. It is likely that the higher rate of comorbidity of borderline personality disorder and binging and purging behaviors, rather than anorexia, is related to the impulsivity which tends to be associated with BPD(“Borderline Personality Disorder And Eating Disorders”). It is also possible that, rather than eating disorders being merely a means of modifying their bodies, those with borderline personality disorder use eating disorders as a means of self-injury, as borderlines in general are susceptible to such behaviors.
Caldwell, James. Eating Disorders and Personality Disorders. A Study In Comorbidity.Retrieved: http://www.vanderbilt.edu/AnS/psychology/health_psychology/pers_dis.htm