Hi Fuzzy!

Great question! This question comes up often.

There is the idea that BP and BPD are basically the same "disorder." There is also the idea that people with BP all have BPD traits.

Bipolar Disorder is a mood disorder.
Borderline Personality Disorder is a personality disorder.

Both experience mood swings. Mood changes in Bipolar tend to last for longer periods of time.

The mood swings of Borderline Personality Disorder can occur rapidly and even several times a day. These rapid BPD mood changes have a tendency to be highly emotional responses to something occurring in the environment. The rather rapid, frequent mood changes/swings demonstrate what Bluebicycle has noted as "emotional dysregulation." BPD also includes other features which are not found in in BP.. I won't go into those.

A person challenged with both "conditions" will likely show/experience signs/symptoms of both.

I want to add some very important information:

Pdocs and T's used to fully believe a person suffering BPD would never recover. I mention this because there is still some old/outdated info around which reflects these old beliefs. Please do not be dismayed should you/anyone stumble upon any source of info which portrays BPD as a condition which cannot be successfully treated. These old beliefs are not true.

There are approaches available now (which were not available before) that truly assist the person suffering BPD to learn how to better regulate emotions, which helps in learning to negotiate healthier relationships and , quite often, assists in achieving very successful lives. While some medications might be used in treating BPD, BPD treatment now tends to focus upon learning/employing DBT and/or CBT skills, etc. This is extremely wonderful and very hopeful news for all!

I hope this answers your inquiry, Fuzzy, my friend!