The relationship between borderline personality disorder and bipolar disorder

Area of Science:

• Psychiatry
• Clinical Psychology

Background:

• Bipolar disorder and borderline personality disorder (BPD) are distinct diagnoses.
• Clinical differentiation is essential for effective treatment.
• The relationship between BPD and bipolar disorder remains debated, with some research suggesting BPD may be part of a bipolar spectrum.

Purpose of the Study:

• To review diagnostic concordance between BPD and bipolar disorder.
• To assess the comorbidity rates between BPD and bipolar I/II disorders.
• To evaluate the evidence for BPD belonging to the bipolar spectrum.

Main Methods:

• Systematic review of studies examining diagnostic concordance between BPD and bipolar disorder.
• Analysis of comorbidity rates in patients diagnosed with BPD or bipolar disorder.
• Comparison of BPD comorbidity with other personality disorders in bipolar patients and vice versa.

Main Results:

• Approximately 10% of BPD patients had bipolar I, and 10% had bipolar II disorder.
• Around 20% of bipolar II patients had BPD, compared to 10% of bipolar I patients.
• In most cases (80-90%), patients were diagnosed with only one of the disorders.

Conclusions:

• Comorbidity rates between BPD and bipolar disorder are substantial but do not support BPD as part of the bipolar spectrum.
• Bipolar patients more commonly exhibit other personality disorders than BPD.
• BPD patients more commonly exhibit other Axis I disorders (e.g., depression, substance abuse, PTSD) than bipolar disorder.