From the Guidelines
Yes, a patient can have both bipolar disorder and borderline personality disorder simultaneously, which is known as comorbidity. This dual diagnosis occurs in approximately 20% of patients with either condition [@\1@]. The two disorders share overlapping symptoms such as mood instability, impulsivity, and emotional dysregulation, which can make diagnosis challenging. However, they are distinct conditions with important differences: bipolar disorder is characterized by distinct episodes of mania or hypomania alternating with depression, while borderline personality disorder features persistent patterns of unstable relationships, self-image, and emotions.
Key Considerations
- Comorbidities, including personality disorders like borderline personality disorder, are common in patients with mood disorders and should not be excluded from treatment studies unless their onset is properly documented as independent and antecedent to the mood disorder diagnosis [@\1@].
- Treatment typically involves a combination approach, with mood stabilizers like lithium, valproate, or lamotrigine for bipolar symptoms, and dialectical behavior therapy (DBT) or other specialized psychotherapies for borderline personality disorder [@\2@].
- Antipsychotics such as quetiapine or olanzapine may help manage symptoms in both conditions.
- Accurate diagnosis is crucial as treatment approaches differ, and patients with both disorders often require more intensive and carefully coordinated care from mental health professionals who can address both the episodic nature of bipolar disorder and the pervasive personality patterns of borderline personality disorder.
Treatment Approaches
- Dialectical behavioral therapy (DBT) has shown promise in treating adolescents with bipolar spectrum disorders (BPSDs), reducing depressive symptoms and suicidality [@\2@].
- DBT is a manualized treatment that addresses illness-specific aspects of BPSDs using a DBT framework, covering the four core DBT modules (i.e., mindfulness, emotion regulation, distress tolerance, and interpersonal effectiveness).
- Modifications to DBT for adolescents with BPSDs include a longer length of treatment, a single-family skill training format, skills and activities tailored to the BPSD, and a focus on the importance of sleep and treatment adherence.
From the Research
Comorbidity of Bipolar Disorder and Borderline Personality Disorder
- The comorbidity rate of bipolar disorder and borderline personality disorder is quite high, with approximately 20% of individuals with bipolar disorder meeting the criteria for comorbid borderline personality disorder 1.
- Studies have shown that individuals with comorbid bipolar disorder and borderline personality disorder have a more severe and phenomenologically distinct clinical course compared to those with bipolar disorder alone 1, 2.
- The relationship between bipolar disorder and borderline personality disorder is complex, and research has yielded differing conclusions on whether borderline personality disorder should be considered part of a bipolar spectrum 3.
Diagnostic Considerations
- It is important to carefully evaluate and differentiate between bipolar disorder and borderline personality disorder, as they can demonstrate common features in the diagnostic aspect and overlap phenomenologically 4, 3.
- The quality of mood fluctuations, impulsivity types, and linear progression of disorders should be carefully considered to differentiate between the two disorders 4.
- Approximately 10% of patients with borderline personality disorder have bipolar I disorder, and another 10% have bipolar II disorder, while approximately 20% of bipolar II patients are diagnosed with borderline personality disorder 3.
Treatment Considerations
- There are no formal treatment guidelines for individuals with comorbid bipolar disorder and borderline personality disorder, and treatments have generally not been tested in this specific population 1.
- Mood stabilizers and atypical antipsychotics have been used in the treatment of borderline personality disorder, with some studies showing efficacy for valproate and lamotrigine 4, 5.
- Psychotherapeutic approaches have preserved their significant places in the treatment of borderline personality disorder, and a symptom-based approach is recommended in the use of mood stabilizers and atypical antipsychotics 4.