Axis I comorbidity of borderline personality disorder

The purpose of this study was to assess the lifetime rates of occurrence of a full range of DSM-III-R axis I disorders in a group of patients with criteria-defined borderline personality disorder and comparison subjects with other personality disorders.

The axis I comorbidity of 504 inpatients with personality disorders was assessed by interviewers who were blind to clinical diagnosis and who used a semistructured research interview of demonstrated reliability.

Four new findings emerged from this study. First, anxiety disorders were found to be almost as common among borderline patients (N=379) as mood disorders but far more discriminating from axis II comparison subjects (N=125). Second, posttraumatic stress disorder (PTSD) was found to be a common but not universal comorbid disorder among borderline patients, a finding inconsistent with the view that borderline personality disorder is actually a form of chronic PTSD. Third, male and female borderline patients were found to differ in the type of disorder of impulse in which they "specialized." More specifically, substance use disorders were significantly more common among male borderline patients, while eating disorders were significantly more common among female borderline patients. Fourth, a lifetime pattern of complex comorbidity (i.e., met DSM-III-R criteria for both a disorder of affect and a disorder of impulse at some point before the patients' index admission) was found to have strong positive predictive power for the borderline diagnosis as well as a high degree of sensitivity and specificity.

These results suggest that the lifetime pattern of axis I comorbidity characteristic of borderline patients and distinguishing for the disorder is a particularly good marker for borderline personality disorder.