What's the difference between borderline personality disorder and bipolar disorder?

The minimalist would say that they are simply two different patterns in the way some people behave. Borderline Personality Disorder (BPD) refers to a persistent and pervasive pattern of interpersonal deficits and other symptoms, where Bipolar Disorder (BD) refers to people who have recurrent episodes of distinctly different, persistently and abnormally mood for at least one week at a time. He would go on to emphasize, however, that these are simply two different patterns, and that they say nothing about the person in question or the reasons they have these patterns of symptoms.

The pseudoscientist would say that although Bipolar Disorder is a disease, and Borderline Personality Disorder is a problem brought on by child abuse, they are actually on a spectrum with most people having a combination of the two. He would go on to say, in fact, that it takes a highly trained expert to be able to tell the difference between the two because they are is so much overlap.

The first argument is not too helpful because it actually does not say much. The second argument is a load of crock because it is not based on any substantial scientific data.

Well A) some people don't believe the Borderline Personality Disorder even exists.

and B) if you look at any symptom list you can see that they are very different. For example, people with Borderline Pers D. are self-destructive almost all the time where as people with Bipolar go through phases of being self destructive and all that, and phases where they are not like that. But there are tons of other differences, just Google it.
http://www.nimh.nih.gov/healthinformatio...

You will find them both listed there at the same website.. there are several major differences.. and it is not uncommon for both distinct afflictions to exist in the same individual.
These two disorders have little in common a person with Borderline personality is listed on axis two of the dsmIv which means it can not be treated now I happen to disagree with that assessment but these folks are a tough group to treat in that no medication is specifically for borderline they are also hard because they love you one day and hate you the next abuse or trauma are thought to be the cause of this problem Bi -Polar on the other hand is listed on axis one of the DSMIV and is caused by a chemical inbalance in the brain which can be treated with drugs such as depakote it is marked by periods of deppression followed by periods of manic episodes if these two symptoms happen four or more times a year then the person is a rapid cycler
masters in mental health
I have BPD. No bi-polar.

I was in therapy when I found out by accident that that was my diagnosis. I wanted to die. There is no cure but it is treatable. After nine years, my therapist said he would not diagnose me with BPD.

Borderline personality disorder (BPD) is a serious mental illness characterized by pervasive instability in moods, interpersonal relationships, self-image, and behavior. This instability often disrupts family and work life, long-term planning, and the individual's sense of self-identity. Originally thought to be at the "borderline" of psychosis, people with BPD suffer from a disorder of emotion regulation. While less well known than schizophrenia or bipolar disorder (manic-depressive illness), BPD is more common, affecting 2 percent of adults, mostly young women. There is a high rate of self-injury without suicide intent, as well as a significant rate of suicide attempts and completed suicide in severe cases. Patients often need extensive mental health services, and account for 20 percent of psychiatric hospitalizations. Yet, with help, many improve over time and are eventually able to lead productive lives.

Symptoms
While a person with depression or bipolar disorder typically endures the same mood for weeks, a person with BPD may experience intense bouts of anger, depression, and anxiety that may last only hours, or at most a day. These may be associated with episodes of impulsive aggression, self-injury, and drug or alcohol abuse. Distortions in cognition and sense of self can lead to frequent changes in long-term goals, career plans, jobs, friendships, gender identity, and values. Sometimes people with BPD view themselves as fundamentally bad, or unworthy. They may feel unfairly misunderstood or mistreated, bored, empty, and have little idea who they are. Such symptoms are most acute when people with BPD feel isolated and lacking in social support, and may result in frantic efforts to avoid being alone.

People with BPD often have highly unstable patterns of social relationships. While they can develop intense but stormy attachments, their attitudes towards family, friends, and loved ones may suddenly shift from idealization (great admiration and love) to devaluation (intense anger and dislike). Thus, they may form an immediate attachment and idealize the other person, but when a slight separation or conflict occurs, they switch unexpectedly to the other extreme and angrily accuse the other person of not caring for them at all. Even with family members, individuals with BPD are highly sensitive to rejection, reacting with anger and distress to such mild separations as a vacation, a business trip, or a sudden change in plans. These fears of abandonment seem to be related to difficulties feeling emotionally connected to important persons when they are physically absent, leaving the individual with BPD feeling lost and perhaps worthless. Suicide threats and attempts may occur along with anger at perceived abandonment and disappointments.

People with BPD exhibit other impulsive behaviors, such as excessive spending, binge eating and risky sex. BPD often occurs together with other psychiatric problems, particularly bipolar disorder, depression, anxiety disorders, substance abuse, and other personality disorders.

Treatment
Treatments for BPD have improved in recent years. Group and individual psychotherapy are at least partially effective for many patients. Within the past 15 years, a new psychosocial treatment termed dialectical behavior therapy (DBT) was developed specifically to treat BPD, and this technique has looked promising in treatment studies. Pharmacological treatments are often prescribed based on specific target symptoms shown by the individual patient. Antidepressant drugs and mood stabilizers may be helpful for depressed and/or labile mood. Antipsychotic drugs may also be used when there are distortions in thinking.

Recent Research Findings
Although the cause of BPD is unknown, both environmental and genetic factors are thought to play a role in predisposing patients to BPD symptoms and traits. Studies show that many, but not all individuals with BPD report a history of abuse, neglect, or separation as young children. Forty to 71 percent of BPD patients report having been sexually abused, usually by a non-caregiver. Researchers believe that BPD results from a combination of individual vulnerability to environmental stress, neglect or abuse as young children, and a series of events that trigger the onset of the disorder as young adults. Adults with BPD are also considerably more likely to be the victim of violence, including rape and other crimes. This may result from both harmful environments as well as impulsivity and poor judgement in choosing partners and lifestyles.

Hope this helps.
National Institute of Mental Health (on line).