What's the Difference Between Bipolar Disorder and Borderline Personality Disorder (BPD)

Bipolar disorder vs. borderline personality disorder

Bipolar disorder and borderline personality disorder (BPD) are often mistaken for each other. In fact, psychiatrists who specialize in mood disorders frequently see patients who have been told they might have one or the other. The confusion makes sense: both involve mood instability and impulsivity.

But each disorder is distinct. The distinction comes down to what kind of condition each one is and how symptoms show up over time.

Bipolar disorder is a mood disorder that involves distinct mood episodes that last weeks or months and are separated by periods of stability. These episodes are a clear departure from how the person usually feels.

BPD is a personality disorder that involves ongoing challenges with emotional regulation, maintaining relationships, and sense of self. Mood shifts can happen quickly and are often triggered by stress from interpersonal relationships.

What is bipolar disorder?

Bipolar disorder is a mood disorder characterized by extreme shifts in mood, energy, and activity levels that occur in distinct episodes.

• Manic or hypomanic episodes are characterized by elevated moods or irribtability.
• Depressive episodes are marked by low moods.

Between episodes, many people return to a stable baseline.

Bipolar I disorder

Bipolar I is defined by the presence of at least one full manic episode lasting at least seven days, or severe enough to require hospitalization. Most people with bipolar I also experience major depressive episodes. A major depressive episode isn't required for diagnosis.

Bipolar II disorder

Bipolar II involves a pattern of hypomanic episodes and major depressive episodes. Hypomania is less severe than full mania and doesn't lead to hospitalization, but the depressive episodes can be long-lasting.

Bipolar II isn't a "milder" form of bipolar I. It's a distinct diagnosis.

Understanding the difference between bipolar II and borderline personality disorder is particularly important, since both can involve significant depressive symptoms.

Cyclothymia

Cyclothymia is a milder, more chronic form of bipolar disorder. It involves numerous periods of hypomanic symptoms and depressive symptoms lasting at least two years. The symptoms don't meet the full criteria for a hypomanic or major depressive episode.

What is borderline personality disorder?

Borderline personality disorder is marked by a persistent pattern of rapid mood shifts, an unstable sense of self, and unstable relationships, along with a fear of abandonment. These patterns of thinking and behavior are ongoing and affect many areas of life. They aren't limited to distinct episodes.

Core features of BPD include:

• Emotional instability: Rapid, reactive mood shifts, often lasting only a few hours. These are typically in response to interpersonal events like conflict, rejection, or other relationship stress.
• ‍Unstable relationships: A pattern of relationships that alternate between feeling intensely close to someone and feeling deeply hurt, angry, or disappointed by them.
• ‍Identity disturbance: A persistently unstable sense of self or self-image. Personal goals, values, or sense of identify may change often.
• ‍Fear of abandonment: Strong fears of being left or rejected, which can lead to urgent efforts to prevent real or perceived abandonment. ‍
• Impulsive behavior: Engaging in impulsive behaviors in at least two areas that are potentially self-damaging, such as spending money, substance use, or risky sexual behavior.

Bipolar disorder symptoms vs. BPD symptoms

While both conditions involve mood changes and impulsivity, the pattern and context of symptoms help clinicians tell them apart.

Bipolar disorder symptoms

Bipolar disorder symptoms occur in distinct episodes. The episodes are a noticeable change from a person's usual state.

Manic symptoms may include:

• elevated or irritable mood
• decreased need for sleep without feeling tired
• racing thoughts or talking faster than usual
• grandiosity or inflated self-esteem
• a marked increase in goal-directed activity or energy

Depressive symptoms may include:

• persistent sadness or hopelessness
• low energy and fatigue
• changes in sleep or appetite
• difficulty concentrating
• loss of interest in activities once enjoyed

BPD symptoms

BPD symptoms occur as part of an ongoing, long-term pattern rather than occuring in separate, clearly defined episodes.

• chronic feelings of emptiness
• intense and highly unstable relationships
• unstable self-image or sense of identity
• impulsivity in areas like spending, sex, or substance use
• recurrent suicidal behavior, gestures, or threats, or self-harming behavior
• stress-related paranoia or dissociative symptoms
• inappropriate anger or difficulty controlling anger

How do mood disorders differ from personality disorders?

Mood disorders involve episodic changes in a person's emotional state. Personality disorders involve enduring, pervasive patterns of thinking, feeling, and behaving that are relatively stable over time.

• Mood disorders (like bipolar): Characterized by distinct episodes of illness, like mania or depression, that represent a clear change from baseline functioning. Between episodes, mood may return to normal. The state between episodes is called euthymia.
• ‍Personality disorders (like BPD): Characterized by long-standing, inflexible patterns of inner experience and behavior. The patterns are part of how a person consistently experiences themselves and the world, rather than episodic.

Someone with bipolar disorder might say, "I wasn't myself during that episode." With BPD, the patterns are more woven into how someone experiences life on an ongoing basis.

What causes bipolar disorder and BPD

Both conditions have complex causes that involve a combination of genetic, biological, and environmental factors. However, the specific contributing factors often differ.

Bipolar disorder causes

Bipolar disorder is thought to primarily be caused by biological factors. It often runs in families, suggesting a genetic link. Differences in brain structure and neurotransmitter function are also believed to play a role. Environmental factors like stress or trauma can potentially trigger episodes in people who are already at increased risk.

BPD causes

BPD is thought to be caused by a mix of genetics and environment factors. Many people with BPD have a history of childhood trauma, abuse, or neglect, though not everyone with such experiences develops the condition. Research points to differences in brain areas that control emotion regulation and impulsivity.

How do psychiatrists diagnose bipolar disorder and borderline personality disorder?

Diagnosis for either condition involves:

• a comprehensive psychiatric evaluation
• a detailed clinical interview
• a careful assessment of symptom patterns over time

Bipolar disorder and BPD cannot be diagnosed through brain scans or blood tests. Instead, diagnosis relies on the expertise of a licensed mental health professional, such as a psychiatrist or therapist, differentiating between the two.

To make a diagnosis, they will typically consider:

• Timeline of symptoms: Are mood changes episodic and lasting for days or weeks (suggesting bipolar disorder), or are they chronic, moment-to-moment, and reactive (suggesting BPD)?
• ‍Triggers: Do mood shifts occur spontaneously, or are they primarily a reaction to interpersonal events? The latter is more characteristic of BPD.
• ‍Sleep patterns: A decreased need for sleep without feeling tired during a period of elevated mood is a hallmark symptom of mania in bipolar disorder.
• ‍Self-image: A chronic and pervasive pattern of an unstable sense of self points more toward BPD.
• ‍Relationship patterns: A history of unstable relationships characterized by a fear of abandonment is a core feature of BPD.

Misdiagnosis is common. That's why a thorough evaluation by a qualified mental health professional is essential for an accurate diagnosis.

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How do treatments differ for bipolar disorder vs. BPD?

Treatment approaches for bipolar disorder and BPD differ significantly. That's one of the main reasons getting an accurate diagnosis matters.

Bipolar disorder treatment is centered on medication to stabilize mood, while BPD treatment is centered on specialized, skills-based psychotherapy.

Bipolar disorder treatment

Medication is the cornerstone of treatment for bipolar disorder. Mood stabilizers (like lithium or valproate) and atypical antipsychotics are typically used to manage manic and depressive episodes. Antidepressants may be used in some cases, but they're typically prescribed cautiously alongside a mood stabilizer to avoid triggering mania.

Therapy, such as cognitive behavioral therapy (CBT), can be a helpful addition to medication for managing symptoms and improving coping skills. However, ongoing medication management is typically necessary for long-term stability.

BPD treatment

Therapy is the cornerstone of treatment for BPD. Dialectical behavior therapy (DBT) is the most well-researched treatment. DBT focuses on teaching skills in:

• mindfulness
• distress tolerance
• emotion regulation
• interpersonal effectiveness

Other therapies like mentalization-based therapy (MBT) can also be effective.

While there are no FDA-approved medications specifically for BPD, a psychiatrist may prescribe medications to target specific symptoms like mood instability, impulsivity, or co-occurring depression. Medications are used as an adjunct to therapy, not as the primary treatment.

Can you have both bipolar disorder and BPD?

Yes, it's possible to have both bipolar disorder and BPD at the same time. When you have two conditions at the same time, it's known as comorbidity. When the conditions co-occur, the overlapping symptoms of mood instability and impulsivity can make diagnosis particularly challenging.

Having both conditions may require an integrated treatment plan that addresses the episodic nature of bipolar disorder with medication while also using therapy to manage the pervasive patterns of BPD. Working with a psychiatrist experienced in complex presentations can help ensure both conditions are addressed appropriately.

Which is worse: BPD or bipolar disorder?

Neither condition is inherently "worse" than the other. Both bipolar disorder and BPD are serious mental health conditions that can significantly impact a person's quality of life, relationships, and overall functioning if left untreated. Both are also treatable.

The severity of each condition varies greatly from person to person. Comparing them is less helpful than focusing on obtaining an accurate diagnosis and an effective, personalized treatment plan.

The bottom line

Bipolar disorder and BPD are two distinct conditions that require different treatment methods, but symptoms can overlap. That's why it's important to get an accurate diagnosis.

If you're unsure which condition might apply to you, or if you've been given conflicting information in the past, a comprehensive evaluation from a psychiatrist can help clarify what's going on and what kind of treatment is most likely to help.

Getting started with Talkiatry

Talkiatry is a national psychiatry practice that makes it easier to get care from doctors who listen. Start by answering a few questions online, then get matched with a psychiatrist based on your needs. From there, you can schedule a visit, often within days, and meet with your provider from home.

First visits are 60 minutes, so there's time to talk through what's going on and build a treatment plan together. Talkiatry is in-network with most major insurers, and you can check your coverage during the assessment.

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Frequently asked questions

Can bipolar disorder be misdiagnosed as borderline personality disorder?

Yes, misdiagnosis can occur in both directions because both conditions involve significant mood instability and impulsivity. A comprehensive psychiatric evaluation that carefully examines the timeline and triggers of symptoms is important for distinguishing between them.

How long do mood episodes last in bipolar disorder compared to BPD?

Bipolar mood episodes are sustained, typically lasting for days, weeks, or even months. In contrast, the mood shifts in BPD are much more rapid, often occurring within hours, and are usually a direct reaction to interpersonal events.

Can bipolar disorder or BPD be diagnosed through telehealth?

Yes, a psychiatrist can conduct a comprehensive evaluation, assess symptoms, and make an accurate diagnosis for either condition through telehealth. The process involves a detailed clinical interview and assessment of symptom history, just as would be done in person.

Are medications used differently for bipolar disorder and BPD?

Yes, medication is a primary treatment for bipolar disorder, and may include mood stabilizers and antipsychotics to manage episodes. For BPD, therapy is the main treatment, and medications are only used as an adjunct treatment to target specific symptoms rather than the disorder itself.

Is there a genetic link for bipolar disorder and borderline personality disorder?

Yes, both conditions have genetic components, meaning they can run in families. However, environmental factors, such as stress and trauma, also play a significant role in the development of both disorders.

Medical disclaimer and sources

The information in this article is for informational and educational purposes only and should never be substituted for medical advice, diagnoses, or treatment. If you or someone you know may be in danger, call 911 or the National Suicide and Crisis Lifeline at 988 right away.

Sources

1. American Psychiatric Association. (2022). Practice guideline for the treatment of patients with bipolar disorder. https://psychiatryonline.org/doi/book/10.1176/appi.books.9780890425787
2. Bipolar disorder. (2024). https://www.nimh.nih.gov/health/topics/bipolar-disorder
3. Borderline personality disorder. (2024). https://www.nimh.nih.gov/health/topics/borderline-personality-disorder
4. What are bipolar disorders? (2024). https://www.psychiatry.org/patients-families/bipolar-disorders/what-are-bipolar-disorders
5. Zimmerman M, et al. (2013). The relationship between borderline personality disorder and bipolar disorder. https://pubmed.ncbi.nlm.nih.gov/24174890/

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