- The main difference between
borderline personality disorder and bipolar is that those with bipolar experience grace periods where they have no symptoms. Bipolar disorder appears to be more of a genetic condition than borderline personality disorder, which is more likely to be caused by childhood trauma.- Both bipolar disorder and borderline personality disorder can be treated with therapy.
- This article was medically reviewed by David A. Merrill, MD, PhD, psychiatrist and director of the Pacific Brain
Health Center at Pacific Neuroscience Institute at Providence Saint John's Health Center.
Borderline personality disorder and bipolar disorders are sometimes associated with one another. But, contrary to popular belief, the two
What's the difference between borderline personality disorder and bipolar disorder?
Both borderline personality disorder and bipolar disorder alter a person's moods, affect their energy levels, impact how they handle emotions, and influence their behavior. But, there are key differences in how these two disorders present, what causes their onset, and how they can be managed.
Bipolar disorder is considered a mood disorder, characterized by fluctuations in a person's emotions, energy, and levels of activity. Those with bipolar disorder experience manic episodes where they feel elated or irritable, energetic, and impulsive. Those with bipolar disorder may also experience depressive episodes where they feel deeply sad and hopeless. Read more about the different types of bipolar disorder.
Borderline Personality Disorder (BPD) is a personality disorder characterized by ongoing shifts in mood, relationships, self-image, and behavior. Someone with borderline personality disorder may experience episodes of anger, depression, anxiety that last from a few hours to days. Those with the disorder are also prone to changing their interests and values quickly as they are uncertain about how they see themselves and their role in the world.
Bipolar disorder is approximately twice as common as borderline personality disorder: 2.8% of US adults are diagnosed with bipolar disorder whereas 1.4% of US adults are diagnosed with borderline personality disorder.
Difference in symptoms
Although the two disorders are distinct mental health conditions, they can share similar symptoms making it difficult at times to differentiate between the two.
Overlapping symptoms include:
- Impulsive behaviors like gambling, unprotected sex, and substance abuse
- Intense shifts in mood that can cause feelings of happiness or irritability
- Mood swings that affect one's energy levels
- Suicidal thoughts
However, there are some key distinctions between the two disorders.
With bipolar disorder, a person experiences periods of relative emotional stability in between episodes of mania and depression. The mood swings associated with bipolar disorder often begin randomly, with no apparent trigger.
Meanwhile, the mood fluctuations in someone with borderline personality disorder experiences are most often triggered by something specific. Though often the trigger is minor, the reaction becomes disproportionately intense.
Other symptoms distinct to borderline personality disorder include:
- Efforts to avoid actual or perceived abandonment
- A history of intense and fluctuating interpersonal relationships often due to something known as "splitting" where a person with borderline personality alternates their view of someone between extreme idealization and devaluation.
- Consistently unstable self-image
- Destructive behavior such as self-harm
- Constant feelings of sadness
- Periods of dissociation where one feels disconnected from thoughts, feelings, memories, and surroundings
Causes of bipolar disorder and borderline personality disorder
The causes for bipolar disorder and borderline personality disorder appear to be the result of some combination of genetics, atypical brain structure, and environmental stressors like childhood trauma.
Genetics
While researchers are still unsure of the exact causes behind both bipolar disorder and borderline personality disorder, they do know there is a genetic component to each.
"With most psychiatric disorders, it's probably a combination of genetic and environmental stressors. Bipolar disorder is usually mainly genetic. Most people with bipolar disorder have a family history of it," says Elspeth Cameron Ritchie, a psychiatrist and chair of Psychiatry at MedStar Washington Hospital Center.
According to a 2012 study published in the Journal of Psychiatry & Neuroscience, a person with one close relative like a sibling or cousin who has bipolar disorder has a 15% to 30% greater chance of also developing the condition. If a person has two first-degree relatives with bipolar disorder, that chance rises to 75%
A 2017 study published in Translational Psychiatry found that borderline personality disorder also has a genetic component. If someone has a family member with borderline personality disorder, there is an estimated 35% to 65% greater chance of developing the disorder.
Traits linked with borderline personality disorder — specifically aggression and impulsivity — are also heritable.
Brain shape
Both conditions also appear to be the result of atypical brain shape and function. A 2017 article published in Molecular Psychiatry found that individuals with bipolar disorder had an abnormally shaped hippocampus — which is responsible for self-control and behavior regulation — with some areas being smaller than the average brain.
Those with borderline personality disorder also appear to have a smaller hippocampus. But, unlike those with bipolar disorder, their amygdalas and part of their prefrontal cortexes were also smaller.
The amygdala, which is located behind the hippocampus, is vital to emotional processing and plays an integral role in regulating negative emotions like anger. The prefrontal cortex, located in the front of the brain, is directly connected to a person's impulsivity.
Trauma
The main difference in the cause of borderline personality disorder and bipolar disorder is that bipolar disorder is mostly a genetic mental health condition, aggravated by severe mental or physical stressors like sexual or physical abuse.
While there may be a genetic component to borderline personality disorder, it is not as well understood as it is in bipolar disorder. Therefore, researchers believe borderline personality disorder is more likely to develop in response to life-altering trauma like abuse, abandonment, or adversity in childhood.
Difference in diagnosis
Both of these disorders are highly complex and must be diagnosed by a mental health professional like a psychiatrist. It's virtually impossible to self-diagnose, says Ritchie.
As symptoms of mental health disorders can overlap, it is not uncommon for someone with borderline personality disorder or bipolar disorder to be misdiagnosed. But, it's hard to know how often this occurs.
In one example, for a 2009 study published in the Journal of Psychiatric Research with 52 borderline personality disorder participants, researchers found that nearly 40% of them were misdiagnosed with bipolar disorder before receiving a correct diagnosis.
It should also be noted that an estimated 15% of individuals with borderline personality disorder also have bipolar disorder.
Difference in treatments
Bipolar disorder and borderline personality disorder are both treated with various forms of psychotherapy and medication. But like any mental disorder, treatment varies across individuals.
According to Richie, finding the correct combination of medications to treat bipolar disorder may take time, but once determined, symptoms can be successfully managed. Bipolar disorder may be treated with a combination of different therapies like family-focused therapy or cognitive-behavioral therapy.
Bipolar disorder treatment also typically includes some form of medication, usually a mood stabilizer like lithium or valproic acid, Richie says. Mood stabilizers can help overstimulated and overactive areas of the brain to prevent manic episodes.
Like bipolar disorder, borderline personality disorder may also be treated with CBT. However, dialectical behavioral therapy (DBT) is a type of therapy more commonly used as it was developed to specifically treat the condition. DBT involves teaching a person coping mechanisms for managing emotions, tolerating distress, and improving their relationships.
So far there is no FDA approved medication to treat borderline personality disorder. Though, like bipolar disorder, medications like mood stabilizers and antidepressants are prescribed as part of treatment.
Takeaway
Bipolar disorder and borderline personality disorder are both mental health disorders that involve similar symptoms.
However, unlike episodic bipolar disorder, those with borderline personality tend to have constant emotional instability and they may struggle to maintain close relationships and consistent interests or values.
Both disorders can be managed through treatment that involves therapy and medication.