Affective instability and impulsivity in borderline personality and bipolar II disorders: similarities and...

Area of Science:

• Psychiatry
• Clinical Psychology
• Neuroscience

Background:

• High comorbidity exists between mood disorders like bipolar disorder and borderline personality disorder.
• Family co-transmission suggests potential shared genetic or environmental factors.
• Few studies have directly compared personality traits to understand dimensional overlap.

Purpose of the Study:

• To compare impulsivity, affective lability, and intensity in patients with borderline personality disorder (BPD) and bipolar II disorder (BPII).
• To investigate dimensional overlap in personality traits between BPD and BPII.
• To differentiate BPD from BPII based on specific personality dimensions.

Main Methods:

• Assessed patients with BPD only (n=29), BPII only (n=14), comorbid BPD and BPII (n=12), and other personality disorders (OPD; n=93).
• Utilized Affective Lability Scale (ALS), Affect Intensity Measure (AIM), Buss-Durkee Hostility Inventory (BDHI), and Barratt Impulsiveness Scale (BIS-7B).

Main Results:

• Borderline personality disorder patients showed significantly higher affective lability (ALS) and impulsivity (BIS-7B) and hostility (BDHI).
• Bipolar II disorder patients exhibited affective lability patterns between euthymia/depression/elation.
• A significant interaction for lability between anxiety and depression was noted in comorbid cases.

Conclusions:

• Both BPD and BPII involve affective lability, potentially explaining mood stabilizer efficacy in both.
• BPD is not merely an attenuated form of affective disorders.
• Distinct patterns of impulsivity, hostility, and affective lability differentiate BPD and BPII.