Abstract
BACKGROUND: Axis I comorbidity complicates diagnosing axis II personality disorders (PDs). PDs might influence Axis I outcome. No research has examined psychotherapy effects on PDs of treating Axis I comorbidity. Secondary analysis of a randomized controlled trial examined PD diagnostic stability after brief psychotherapy of chronic posttraumatic stress disorder (PTSD). METHODS: Patients with chronic PTSD were randomly assigned to 14 weeks of prolonged exposure, interpersonal psychotherapy, or relaxation therapy. Assessments included the Structured Clinical Interview for DSM-IV, Patient Version (SCID-P) and Structured Clinical Interview for DSM-IV Axis II Disorders (SCID-II) at baseline, week 14, and for treatment responders (≥30% clinician-administered PTSD scale improvement, defined a priori) at week 26 follow-up. We hypothesized patients whose PTSD improved would retain fewer baseline PD diagnoses posttreatment, particularly with personality traits PTSD mimics, e.g. paranoid and avoidant. RESULTS: Forty-seven (47%) of 99 SCID-II patients evaluated at baseline received a SCID-II diagnosis: paranoid (28%), obsessive-compulsive (27%), and avoidant (23%) PDs were most prevalent. Among 78 patients who repeated SCID-II evaluations posttreatment, 45% (N = 35) had baseline PD diagnoses, of which 43% (N = 15/35) lost at week 14. Three (7%) patients without baseline PDs acquired diagnoses at week 14; 10 others shifted diagnoses. Treatment modality and PTSD response were unrelated to PD improvement. Of treatment responders reevaluated at follow-up (N = 44), 56% with any baseline Axis II diagnosis had none at week 26. CONCLUSION: This first evaluation of Axis I psychotherapy effects on personality disorder stability found that acutely treating a chronic state decreased apparent trait-across most PDs observed. These exploratory findings suggest personality diagnoses may have limited prognostic meaning in treating chronic PTSD.