Bipolar Disorder And Borderline Personality Disorder: What Are The Differences?

Is There A Relationship Between BPD And BP?

Look into research investigating the relationship between Bipolar Disorder and Borderline Personality Disorder, and you'll immediately notice that one name pops up a lot: Mark Zimmerman MD. Dr Zimmerman is the Director of Outpatient Psychiatry at Rhode Island Hospital and director of the Rhode Island Methods to Improve Diagnostic Assessment and Services (MIDAS) project. 

A study he worked on shows that there is a relationship between BPD and BP. Around 10 percent of BPD patients was found to have Bipolar I Disorder, while a further 10 percent had Bipolar II Disorder. Similarly, 20 percent of people diagnosed with Bipolar I Disorder was found to also have BPD. The same held true for 10 percent of people with Bipolar II Disorder. 

This link appears to be significant at first sight, but Dr Zimmerman and his team go on to note that "each disorder is nonetheless diagnosed in the absence of the other in the vast majority of cases (80 percent to 90 percent)". Bipolar patients were also found to be diagnosed with other personality disorders more frequently than with BPD, and Bipolar Disorder was not found to be the most common co-diagnosis with BPD either. 

Zimmerman and his team note that some mental health professionals have wondered whether BPD falls somewhere on the Bipolar spectrum, and that varying conclusions have been made on this.

Another study, again led by Mark Zimmerman MD, investigated the differences between Bipolar Disorder and Borderline Personality Disorder. It found that BPD patients were more likely to have been victims of childhood trauma, and that they had a higher risk of being diagnosed with additional disorders as well. Additionally, the depressive episodes they go through were found to be more severe and longer-lasting. 

The Differences Between BP And BPD 

What have we learned so far? Both Borderline Personality Disorder and Bipolar Disorder are complex conditions. While it is obvious that patients benefit from the right treatment, we also found out that even clinicians manage to misdiagnose BPD and BP quite frequently.

Why am I mentioning this? Because readers might be interested in DIY-diagnosing themselves or someone they know. If anything, the many questions surrounding BP and BPD in mental health circles should make it clear that this is not possible. Don't do it. Having said that, here are some key differences between Bipolar Disorder and Borderline Personality Disorder. 

Both BP and BPD patients can experience extreme and sudden mood swings that appear in cycles. The length of these cycles varies significantly in Bipolar patients, depending on the sub-type they have. Generally, these cycles vary from once every three months to once every five years. Borderline patients also go through cycles, but they tend to last minutes, hours or days at most. In short, mood cycles are much longer in BP patients than in Borderline patients.

See Also: Bipolar disorder

Another difference is that the moods of Borderline patients are heavily influenced by their environment and past experiences. In particular, mood swings are triggered by perceived or actual abandonment in BPD patients. While Bipolar patients' mood episodes may be influenced by the environment, the link is much less obvious. 

Finally, the moods Borderline people experience are a little like Tinkerbell from Peter Pan. Tinkerbell is said to "only have space for one emotion, so she's all good or all bad, and never both at the same time". When someone with BPD is depressed, they are completely depressed, and when they are angry, they are very angry. Conversely, when they are impressed by someone, they will devote their whole selves to that person — but not for long. Bipolar people might appear to be either depressed or manic, but there is much more room for nuance than there is in people with BPD.