The Eternal Footman --see photo above-- commented on Mood Disorders 101; he (footman, so it's a he, right?) asks:
Okay, I'm going to add one more thought and then I'll shut up. Borderline Personality Disorder is a condition that includes "affective (=mood) instability" and the differentiation between a personality disorder and a mood disorder can be difficult even for experienced psychiatrists.
...raised another question which is: Is there any one or two key symptoms/behaviors that clearly differentiate Borderline Personality Disorder from any one of the mood disorders?
Great question. Easy Answer: No.
Okay, but you inspired a post, so I'll elaborate. How does a psychiatrist differentiate, sometimes unsuccessfully, the diagnostic quandary of mood disorder versus borderline personality disorder? They both entail mood instability and behavioral indiscretions, especially impulsive behaviors during manic and hypomanic episodes, and the results of these illnesses can both result in chaotic lives.
So in my shrinky mind, I'll start with the issue of chronicity and overall quality of life. Someone's trekking along just fine (it doesn't matter when or for how long).... they have a life pattern of being able to work and to love, and suddenly they get zapped with a depression and things start falling apart-- they don't want to socialize, they don't want to work. At some point, with or without treatment, the episode ends and they go back to their regular old life. This person doesn't have borderline personality disorder, they have had an episode of depression. Oh, but we've already said that there a people with chronic depressions which are less easily defined into distinct episodes, and it appears their may be people with bipolar disorder, especially bipolar disorder type II, who spend much of their time cycling into and out of depressions and hypomanias, and they all kind of blur together. The chaos of it all is rather disruptive, and during these not-quite discrete episodes of hypomania, they engage in all sorts of impulsive behaviors: promiscuity, drug use, indiscriminate spending, gambling, fighting.
Simply put, if life is a constant episode of chaotic behavior, if the patient is unable to maintain employment, is often the center of dramatic upheavals regarding interpersonal relationships ( or drama with everything else), if the patient can't maintain some semblance of romantic relationships or friendships and is always struggling with co-workers and employers, then a psychiatrist is going to label this a personality disorder. And to be totally blunt, if this same patient repeatedly threatens suicide in a way that garners the troops, or cuts themselves because it relieves psychic pain, then a psychiatrist will label this Borderline Personality Disorder. If the patient is repeatedly painting pictures of people in black and white-- one moment someone is all good, the next they are all bad, or everyone is one color with no shades of gray, and if he manages to frequently pit the people in his life against one another, well, a psychiatrist is still going to label this Borderline Personality Disorder. Good or bad, right or wrong, that's currently how it goes. The label has a pejorative edge, as if the patient should just grab hold of themselves and stop doing this. These patients often are difficult to deal with, they ask a lot of their physicians and they often get angry at the docs who are trying hard to help them. They may push up against the shrink in such a way that the shrink gets uncomfortable, feels a need to set up clear boundaries, and these boundaries feel rejecting to the patient, who now has one more data point in seeing how everyone is mean to them. The patient may well not see that they had a role in inspiring the reaction. "I need you..." their behavior says, " and you shouldn't be pushing me away." There may be little insight that they are asking too much, that the shrink feels overwhelmed, over-wanted, pushed against the wall in uncomfortable ways.
And the other issue, not for today, is that sometimes psychiatrists label people they don't like with personality disorders rather than taking a careful look at their own roles in interactions that struggle. Diagnostically, the label is a vague one, and it means more than an isolated personality clash...again, for another day.
So the chronic, chaotic, interpersonal issues point more towards a personality disorder than a mood disorder. Self-mutilating behavior (as opposed to suicidality) is not a symptom of mood disorders. And while people with manias may wreak all sorts of havoc, it's an episode, not a lifestyle.
So here's the next question: Does it matter?
There are mood disorder experts out there who will say that if you take people with these chaotic stories, re-think them as having chronic and rapid-cycling mood disorders, and treat them with medications to stabilize their mood, they do better and sometimes the chaos calms down.
There are personality disorder experts out there who say they've never met anyone with borderline personality disorder who doesn't, at least episodically, have a co-morbid mood disorder.
So, I suppose if you're going to say it's Borderline Personality Disorder and the only treatment is long-term intensive psychotherapy and there's no role for even trying medications or considering the possibility of addressing issues of mood or anxiety, then perhaps the treatment options have been kept narrow and uncreative. If therapy alone isn't helping, the patient might consider another opinion. And if meds alone aren't working, then maybe some therapy is in order.