The co-occurring diagnosis of BPD and bipolar disorder is not unusual since many of the symptoms for both disorders present in similar ways.
Common traits of BPD and bipolar disorders include:
Suicidal thoughts or actions
Episodes of impulsive, self-destructive behavior (risky sex, reckless driving, or compulsive shopping)
Depression and self-hatred
Irritability and angry outbursts
Unstable personal relationships
Feelings of emptiness or worthlessness
Those with comorbid bipolar disorder II and BPD demonstrate a compounding effect, in particular for emotion regulation deficit, impulsivity and difficulty for goal-directed behaviours more so than having BP or BPD singly. This is clinically important, as this may mean there is a greater risk for self-harm or suicidal behaviours.
Recommended treatment for comorbid bipolar disorders and BPD is to adopt a multi-tiered model that involves treating the bipolar disorder with mood stabiliser to optimise state-related emotion regulation deficits and then making a long-term commitment to address the emotion regulation deficits contributed by the BPD and the bipolar disorder trait domain by engaging in evidence-based psychotherapies. It is important that there is a right balance in order for for effective treatment to manage stress and control symptoms of both conditions.