Objective: The purpose of this study was to examine the dissociative disorder comorbidity of borderline personality disorder and its relation to childhood trauma reports in a nonclinical population.
Method: In April 2003, 1301 college students were screened for borderline personality disorder using the Structured Clinical Interview for DSM-IV Personality Disorders. The Childhood Trauma Questionnaire and Steinberg's dissociation questionnaires were also administered. During May and June 2003, 80 students with a diagnosis of borderline personality disorder and 111 nonborderline students were evaluated using the Structured Clinical Interview for DSM-IV Dissociative Disorders by an interviewer blind to the diagnosis and scores obtained during the first phase.
Results: The prevalence of borderline personality disorder was 8.5%. A significant majority (72.5%; 58/80) of the borderline personality disorder group had a dissociative disorder, whereas this rate was only 18.0% (20/111) for the comparison group (p < .001). Childhood emotional and sexual abuse, physical neglect, and total childhood trauma scores had significant effect for borderline personality disorder (p < .001, p = .038, p = .044, and p = .003, respectively), whereas emotional neglect and diminished minimization of childhood trauma had significant effect for dissociative disorder (p = .020 and p = .007, respectively).
Conclusion: A significant proportion of subjects with borderline personality disorder have a comorbid dissociative disorder. Lack of interaction between dissociative disorder and borderline personality disorder diagnoses for any type of childhood trauma contradicts the opinion that both disorders together might be a single disorder. Recognizing highly prevalent but usually neglected Axis I dissociative disorder comorbidity in patients with borderline personality disorder may contribute to conceptual clarification of this spectrum of psychopathology.