Examining the Course and Outcome of Individuals Diagnosed with Schizophrenia and Comorbid Borderline Personality Disorder

Background and Purpose: Borderline personality disorder (BPD) is a chronic and persistent mental illness that impedes an individual's ability to maintain affective and behavioral stability in a variety of interpersonal and social contexts. Prior investigations have shown that BPD has a negative impact on the course and outcome of co-occurring affective disorders and places individuals with these conditions at considerable risk for high morbidity. The impact BPD has on schizophrenia is largely unknown, however, the pervasive characteristics would seem to increase the likelihood that this disorder has a negative impact on the illness. Determining whether individuals with schizophrenia and BPD are at similar risk for high morbidity could provide a sufficient knowledge base for social workers to aid in the development and implementation of more specific and effective treatment options for individuals with these conditions. This research investigated the prevalence of BPD in a sample of schizophrenia inpatients, and then examined the degree to which BPD comorbidity impacted symptom and functional outcome trajectories during the year following discharge. Methods: Data were collected from the MacArthur Violence Risk Assessment Study. From this dataset, 142 individuals diagnosed with schizophrenia (n = 120) or schizoaffective disorder (n = 22) were administered the Structured Interview for DSM-III-R Personality (SIDP-R). Symptom and functional outcome data were gathered during hospitalization and at 1-year follow-up to analyze differences in symptom and functioning characteristics between those diagnosed with and without BPD. Cross-sectional differences in symptom and functional outcomes at baseline and 1-year were examined using ANCOVA adjusting age and sex effects and controlling for the presence of substance use disorders. To examine differential symptom and functional 1-year trajectories between individuals with and without BPD, ANCOVA analyses were conducted on follow-up symptom and functional outcome scores, while covaring baseline scores. Results: Our results indicated that comorbid BPD was present in a non-trivial proportion (17.6%, n = 25) of the 142, based on SIDP-R assessment. Baseline analyses indicated that individuals with BPD presented with modest elevations in the severity of psychiatric symptomatology, and higher levels of anxiety and depression, at hospitalization. At follow-up, however, results of ANCOVA models revealed that those with comorbid BPD showed less improvement in symptomatology, particularly hostility and suspiciousness, as well as global functioning. In addition, an examination of hospitalization data indicated that individuals with comorbid BPD were hospitalized nearly two times more frequently during the 1-year follow-up. Conclusions and Implications: Results from this research indicate that the co-occurrence of schizophrenia and BPD is not infrequent and that BPD has a negative longitudinal impact on the course and outcome of individuals with schizophrenia. Unfortunately, current treatment options for individuals with these co-occurring diagnoses are limited, and no existing treatment options for schizophrenia target the more lethal aspects of BPD. Social workers are the primary providers of psychosocial services for individuals with schizophrenia, and it will be important for social work researchers and practitioners to develop more effective intervention approaches for the underserved and highly disabled group of individuals with schizophrenia and comorbid BPD.