Background: The purpose of this study was to assess the prevalence, reliability, and predictive value of comorbid personality disorders in a large sample of 210 women seeking treatment for anorexia nervosa (N = 31), bulimia nervosa (N = 91), or mixed disorder (N = 88).
Method: All subjects were interviewed using the Structured Interview for DSM-III Personality Disorders as part of a longitudinal outcome study of eating disorders currently underway at Massachusetts General Hospital.
Results: Of the 210 subjects, 27% had at least one personality disorder; the most commonly observed was borderline personality disorder in 18 subjects (9%). The highest prevalence of personality disorders was found in the anorexia nervosa/bulimia nervosa group at 39%, followed by 22% in the anorexics and 21% in the bulimic sample. We found statistically significant differences regarding the distribution of personality disorders across eating disorder groups. The dramatic personality disorder cluster was differentially distributed across groups; this finding was accounted for by higher rates of borderline personality disorder in the bulimia nervosa and anorexia nervosa/bulimia nervosa groups than in the anorexia nervosa group. The anxious personality disorder cluster was differentially distributed across groups with higher rates in the anorexia nervosa and anorexia nervosa/bulimia nervosa samples. Those subjects with a comorbid personality disorder had a significantly slower recovery rate than those without a comorbid personality disorder.
Conclusion: The prevalence of personality disorders is not high in treatment-seeking women with eating disorders compared with previously studied samples. The greatest frequency of comorbid personality disorders is in the anorexia nervosa/bulimia nervosa group; this subset also had longer duration of eating disorder illness and much greater comorbid Axis I psychopathology compared with the rest of the sample. Future studies should address whether personality disorders have predictive value in the long-term course and outcome of eating disorders.