The Key Differences Between Bipolar Disorder And Borderline Personality Disorder

Bipolar Disorder and Borderline Personality Disorder both cause extreme mood swings and impulsive behavior. It's hardly surprising that people who are not mental health professionals sometimes confuse the two, but even clinicians may diagnose the wrong disorder — especially if they are using the Mood Disorder Questionnaire (MDQ). 

While BP and BPD (oh no, even the abbreviations are similar!) have some noteworthy similarities, they also come with significant differences. To illustrate this, we'll take a look at both disorders individually and then examine the differences between the two.

Bipolar Disorder

Bipolar Disorder is a condition that goes by many names. Bipolar affective disorder, manic-depressive illness, and affective psychosis are all alternative terms that refer to Bipolar Disorder. This condition is characterized by extreme highs and lows, known as depressive and manic episodes.

Symptoms of a manic episode include long periods of feeling happy or powerful, irritability, speaking fast, expressing seemingly unconnected thoughts, unusually high energy and activity levels, restlessness, lack of sleep and not feeling sleepy either, impulsive behavior, and risk-taking. In short, Bipolar people experiencing a manic episode will feel like they're ready to take over the world. Indeed, they may feel like they already have!

Depressive episodes represent the other side of the Bipolar coin. During this stage, sufferers may feel extremely low and hopeless, lose interest in activities they previously enjoyed, and may even contemplate or attempt suicide. Restlessness and irritability may come with depressive episodes as well, and BP people going through a depressive episode often have difficulty focusing, remembering, and making decisions during this stage. Their eating, sleeping and living patterns will change significantly. Mood episodes can last for weeks.

While the exact mechanism by which people develop Bipolar Disorder remains unclear, scientists do know there is a strong genetic component. Research also shows that there are physical differences in the brains of people with BP, and that environmental factors — such as abuse during childhood — play a significant role.

Bipolar Disorder comes in several sub-types, determined by the severity of the symptoms and the length of mood cycles. It is usually a life-long condition, but Bipolar Disorder can be managed well with medications and therapy. Lithium and anti-convulsants such as Carbamazepine are the go-to medications to treat Bipolar Disorder. These medications have a dramatically successful effect on BP patients. 

Borderline Personality Disorder

The National Institute of Mental Health describes Borderline Personality Disorder (BPD) as a "a serious mental illness marked by unstable moods, behavior, and relationships". The disorder got its name because mental health professionals initially thought of its symptomatic picture as an atypical, or "borderline" presentation of other disorders. 

People who have Borderline Personality Disorder typically have difficulty regulating their thoughts and feelings, display impulsive and reckless behavior, and find maintaining relationships with other people challenging. Some BPD sufferers have psychotic episodes, and the personality disorder also comes with a high-rate of co-existing diagnoses such as depression, anxiety disorders, and eating disorders. 

• Extreme reactions to real or perceived abandonment. These may include panic, depression, rage, or frantic actions. 
• Dysfunctional relationships with others. People with BPD may love you one minute, and hate you the next. If the BPD sufferer thinks you care for them, they are very likely to try to push you away. 
• An unstable and unrealistic self-image, subject to constant change. 
• Impulsive and high-risk behavior — spending sprees, substance abuse, dangerous sexual situations, and others. 
• Recurring suicidal feelings, suicide attempts, self-harming, and other self-destructive behaviors. 
• Extreme mood swings, lasting from hours to days.
• Feeling empty and bored.
• Intense anger problems.
• Dissociation (out-of-body experiences), paranoia, an inability to perceive reality.

See Also: Borderline Personality Disorder (BPD): Emotional Dysregulation

Borderline Personality Disorder is still a little-understood illness, but environmental and genetic factors are both thought to contribute. In part because BPD is still not understood very well, treating this disorder is notoriously difficult. Therapy, including Cognitive Behavioral Therapy and Dialectical Behavior Therapy, is thought to be the best available treatment at the moment. No medications have been approved to treat BPD in the US. 

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.