A Comparison Between Dually Diagnosed Inpatients with and without Axis II Comorbidity and the Relationship to Treatment Outcome

Abstract

The presence of a personality disorder (PD) has been associated with certain types of poor treatment outcomes in patients with substance use disorders (SUDs). The purpose of this study was to determine the prevalence of comorbid PDs in psychiatrically hospitalized adults with both non-SUD Axis I disorders and SUDs, and to assess the relationship between Axis II psychopathology and degree of pretreatment addiction severity and treatment outcome. Method: One hundred consecutive inpatients admitted to a mixed dual diagnosis inpatient unit were assessed using semistructured interviews for SUDs, non-SUD Axis I disorders, and PDs. Pretreatment severity was assessed using a modified version of the Addiction Severity Index (ASI). Outcome measures were assessed both during hospitalization and at an initial follow-up appointment after discharge. Statistical analyses were performed comparing dually diagnosed patients with and without Axis II psychopathology. Results: A significant number (53%) of the patients met criteria for at least one personality disorder. Of the PDs, Cluster B PDs were the most prevalent, particularly borderline personality disorder (74%) and antisocial personality disorder (66%). Dually diagnosed patients without an Axis II diagnosis had less severe pretreatment severity measures. During hospitalization, patients with Axis II disorders had higher levels of psychopathology on the Brief Symptom Inventory (BSI) subscales of sensitivity and hostility. However, there was no difference in overall degree of global improvement during hospitalization. During follow-up, patients with Axis II disorders were significantly less likely to be compliant in attending their initial follow-up appointment. Conclusions: Dual diagnosis inpatients with PDs appear to improve as much as patients without PDs during their inpatient hospitalizations; however, they appear to be less likely to be compliant with attending their initial follow-up appointment.