Bipolar disorder and comorbid personality psychopathology: a review of the literature.

OBJECTIVE: To examine the prevalence of personality disorder comorbidity in bipolar disorder and examine the effects of this comorbidity on bipolar disorder patients.

DATA SOURCES: All the studies reviewed were found through an online literature search through the Web site PubMed. The studies were published between 1980 and 2006. The following keywords were used to search articles: bipolar, mania, mood, personality, Axis II, borderline, and lithium. Only articles in English were included in this literature review.

STUDY SELECTION: A total of 32 studies that reported data on the prevalence and effect of comorbid personality disorders or abnormal personality traits in bipolar disorder patients were reviewed.

DATA EXTRACTION: The data abstracted from the prevalence studies included sample size, mood state of the study population, research instruments used to determine personality psychopathology, prevalence rates of personality disorders, and abnormalities. Other data collected included response to medications and course of illness.

DATA SYNTHESIS: The prevalence studies were categorized into outpatient and inpatient studies to facilitate data analysis. The prevalence studies were also analyzed according to the research instrument used to measure personality pathology. Studies that used non-DSM personality measures were analyzed separately.

CONCLUSIONS: Bipolar disorder patients have significantly higher prevalence of personality disorder than the general population. Several studies reviewed indicate a higher prevalence of Axis II disorders in bipolar patients with unstable mood. However, this finding was not confirmed in comparison of inpatient and outpatient comorbidity rates. Bipolar patients with personality psychopathology have poorer response to medications and a more virulent course of illness.