Is borderline personality disorder underdiagnosed and bipolar disorder overdiagnosed?

Abstract

Both borderline personality disorder (BPD) and bipolar disorder are considered clinically severe, chronic conditions associated with high functional impairment and public health costs. These disorders also share clinical features, most predominantly mood fluctuations and impulsivity across several areas. In this chapter we report research showing that BPD is chronically under-assessed and, as a result, underdiagnosed in clinical populations. Conversely, we also document literature showing the overdiagnosis of bipolar disorder, particularly in cases where, after careful interviewing, patients actually meet criteria for BPD. Reasons for this pattern vary and include insufficient diagnostic rigor, stigma associated with BPD, unfamiliarity with BPD as compared to bipolar disorder, the promotion of bipolar disorder (and not BPD) by pharmaceutical companies, and perceived difficulty in treating BPD as compared to bipolar disorder, among others. Nonetheless, diagnosing BPD and/or bipolar disorder has significant consequences for treatment planning and patient care, and close attention should be paid to making this differential diagnosis in clinical settings.