The Collaborative Longitudinal Personality Disorders Study: baseline axis I/II and II/II diagnostic co-occurrence

Objective: To describe baseline diagnostic co-occurrence in the Collaborati ve Longitudinal Personality Disorders Study. Method: Six hundred and sixty-eight patients were reliably assessed with di agnostic interviews for DSM-IV Axis I and II disorders to create five group s: Schizotypal (STPD), Borderline (BPD), Avoidant (AVPD), Obsessive-Compuls ive (OCPD) and Major Depressive Disorder (MDD) without personality disorder (PD). Results: Mean number of Axis I lifetime diagnoses was 3.4; STPD and BPD gro ups had more diagnoses than AVPD, OCPD, and MDD groups. Significant Axis I co-occurrences emerged for Social Phobia/AVPD, PTSD/BPD and Substance Use/B PD. Mean number of co-occurring PDs was 1.4; STPD had more than BPD group w hich had more than AVPD and OCPD groups. Significant PD co-occurrence emerg ed for: STPD/ Paranoid and Schizoid PDs, BPD with Antisocial and Dependent PDs, and lower frequency for OCPD/Antisocial PD. Conclusion: Diagnostic co-occurrences generally followed base rates, while significant departures resemble those of controlled literature.