Cluster B Personality Disorders: What They Are, Why They Happen, and How They're Treated
Updated: 2 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 14, 2026
Quick Answer
Cluster B personality disorders are a group of four mental health conditions, antisocial, borderline, histrionic and narcissistic, involving dramatic, erratic behaviors and unstable emotions [1] [6]. Their cause is unknown but linked to genetics and adverse childhood experiences [1]. Psychotherapy such as DBT or CBT is the main treatment; no FDA-approved medications treat them directly, though some may help related symptoms [1].
What the research says
Childhood adversity strongly predicts later personality disorder. In 8,199 adolescents followed for 14 years, any adverse childhood experience was linked to a 3.8-fold higher risk of a personality disorder diagnosis in adulthood, and about 90% of those who developed one had such a history. (Broekhof et al., Journal of Personality Disorders, 2024) [2].
Cluster B and Cluster C disorders can be equally burdensome. Comparing 94 patients, those with Cluster B disorders more often had substance use disorders and lifetime suicide attempts, but other severity measures, including trauma and overall functioning, did not differ between groups. (Massaal-van der Ree et al., Behavioral Sciences, 2022) [4].
What Are Cluster B Personality Disorders?
Cluster B personality disorders are a group of mental health conditions that involve dramatic and erratic behaviors. They represent styles of interacting with oneself and others, and these styles involve dramatic and erratic behaviors. People diagnosed with these types of conditions have intense, unstable emotions and act impulsively [1].
Cluster B personality disorders involve impulsive and dramatic behavior. There are four types, including borderline PD and antisocial PD. People with these types of personality disorders often don't realize their thoughts and behaviors are problematic [1] [6].
These behaviors and thinking patterns can cause distress in many areas of life. This includes work, relationships and socialization.
Term | What It Means |
|---|---|
Cluster B personality disorder (PD) | A group of four mental health conditions involving dramatic, erratic behaviors, intense unstable emotions, and impulsive actions |
Personality disorder (PD) | A mental health condition representing a style of interacting with oneself and others |
DSM-5 | The American Psychiatric Association's manual of diagnostic criteria used to diagnose personality disorders |
Psychotherapy (talk therapy) | Treatment with a mental health professional like a psychologist to learn healthier ways of navigating emotions and relationships |
Adverse childhood experiences (ACEs) | Difficult experiences growing up — such as abuse, neglect, and household instability — linked to Cluster B PDs |
What Are the Four Types of Cluster B Personality Disorders?
The four types of Cluster B personality disorders include antisocial PD, histrionic PD, borderline PD, and narcissistic PD [1] [6].
Type | What It Involves |
|---|---|
Antisocial personality disorder (ASPD) | Lack of respect toward others; generally doesn't follow socially accepted rules |
Borderline personality disorder (BPD) | Difficulty regulating emotions, resulting in low self-esteem, mood swings, and impulsive behaviors |
Histrionic personality disorder (HPD) | Intense, unstable emotions and a distorted self-image; overwhelming desire for others to notice them; easily influenced by others |
Narcissistic personality disorder (NPD) | A sense of being better than others; intense need for praise; lack of empathy for others |
The four types of Cluster B personality disorders, each with its own pattern of emotions, thinking, and behavior.
What Are the Common Traits of Cluster B Personality Disorders?
In general, Cluster B disorder traits include being dramatic or overly emotional, impulsiveness, unpredictable or erratic behavior, and difficulty keeping stable relationships [1].
As with many of the other personality disorders (PDs), people living with Cluster B PDs often don't realize there's an issue with their behavior.
Common Trait | What It Looks Like |
|---|---|
Being dramatic or overly emotional | Strong, heightened emotional reactions |
Impulsiveness | Acting without thinking things through |
Unpredictable or erratic behavior | Behavior that is hard for others to anticipate |
Difficulty keeping stable relationships | Trouble maintaining steady partner, friend, or family relationships |
What Causes Cluster B Personality Disorders?
Healthcare providers aren't sure of the exact cause of Cluster B personality disorders. Research suggests that it's complex and may involve many factors, from your genetics to certain experiences you had growing up [1] [6].
Adverse childhood experiences (ACEs) are especially linked to Cluster B PDs [1]. They include physical and sexual abuse, emotional abuse, neglect, and household issues like divorce, money difficulties, and parental mental health conditions [1].
Adverse childhood experiences — abuse, neglect, and household instability — are especially linked to Cluster B personality disorders.
What Complications Can Cluster B Personality Disorders Cause?
Compared to other personality disorder clusters, people with Cluster B disorders are at increased risk of substance use disorders, like alcohol use disorder; suicidal thoughts and attempts; and crime (especially those living with antisocial personality disorder) [1].
As with other PDs, people living with Cluster B PDs are more likely to be diagnosed with mood and/or anxiety disorders, as well [1] [6].
Complication | Details |
|---|---|
Substance use disorders | Like alcohol use disorder |
Suicidal thoughts and attempts | Increased risk compared to other PD clusters |
Crime | Especially among those living with antisocial personality disorder |
Co-occurring mental health conditions | More likely to be diagnosed with mood and/or anxiety disorders |
How Are Cluster B Personality Disorders Diagnosed?
Healthcare providers use criteria in the American Psychiatric Association's DSM-5 to diagnose Cluster B personality disorders [1]. Each PD type has specific criteria. Providers ask questions about a person's medical, personal and social history to guide diagnosis.
Diagnosis can be difficult, as most people living with these conditions may not seek treatment. This is often due to community mental health stigma or a lack of insight into their behaviors. So, mental health professionals may also work with the person's loved ones and other acquaintances to gather more information [1].
How Are Cluster B Personality Disorders Treated?
Psychotherapy (talk therapy) can help you manage living with Cluster B personality disorders [1] [6]. You'll work with a mental health professional, like a psychologist. They can provide support, education and guidance to you and your family. They can also help you learn healthier ways of navigating emotions and relationships.
There are several types of talk therapy. Some types may work better than others for certain Cluster B PDs. For example, dialectical behavior therapy (DBT) tends to be a more effective treatment for BPD [1] [6]. People with HPD often benefit from cognitive-behavioral therapy (CBT) [1].
Currently, there are no FDA-approved medications to treat PDs directly [1]. But you may take medications to treat symptoms of other mental health conditions you may have, like depression and anxiety [1] [6].
Treatment | How It Helps |
|---|---|
Psychotherapy (talk therapy) | A psychologist provides support, education, and guidance, and helps you learn healthier ways of navigating emotions and relationships |
Dialectical behavior therapy (DBT) | Tends to be a more effective treatment for borderline personality disorder |
Cognitive-behavioral therapy (CBT) | People with histrionic personality disorder often benefit from this approach |
Medications | No FDA-approved medications treat PDs directly, but medications may treat symptoms of related conditions like depression and anxiety |
Talk therapy — tailored to the specific Cluster B PD — is the cornerstone of treatment.
What Is the Outlook for Someone With a Cluster B Personality Disorder?
The outlook (prognosis) for Cluster B personality disorders varies. It depends on your willingness to get treatment and how severe your symptoms are [1].
Living with an undiagnosed and untreated Cluster B personality disorder may result in poor relationships, including a lack of stable, healthy partner and friend relationships; work issues; and issues with social functioning, including inaccurately understanding and responding to others' emotional cues and boundaries [1].
But with treatment, it's possible to improve your behaviors, thinking patterns and quality of life [1].
What reassurance is there for people with Cluster B personality disorders?
Cluster B personality disorders are mental health conditions, and like other mental health conditions they can be helped by seeking care early. As with all mental health conditions, seeking help as soon as symptoms appear can help decrease the disruptions to your life [1]. Mental health professionals can design tailored treatment plans that can help you better manage your thoughts and behaviors.
Loved ones of people with PDs can experience stress, depression, grief and isolation [1]. Reach out for help if you have these symptoms.
What is the bottom line on Cluster B personality disorders?
Cluster B personality disorders are a group of four mental health conditions — antisocial, borderline, histrionic, and narcissistic personality disorders — that involve dramatic and erratic behaviors, intense unstable emotions, and impulsive actions [1]. The exact cause isn't known, but genetics and experiences growing up likely play a role, with adverse childhood experiences being especially linked. These conditions cause distress in work, relationships, and social life, and raise the risk of substance use disorders, suicidal thoughts, and mood or anxiety disorders [1]. Treatment centers on talk therapy tailored to the specific disorder — DBT for borderline PD and CBT for histrionic PD — since no FDA-approved medications treat PDs directly. The outlook varies with willingness to get help, but with treatment, behaviors, thinking patterns, and quality of life can improve. Seeking help early is the single most important step.
Frequently Asked Questions
What are Cluster B personality disorders?
Cluster B personality disorders are a group of mental health conditions that involve dramatic and erratic behaviors. They represent styles of interacting with oneself and others, with intense, unstable emotions and impulsive actions.
How many types of Cluster B personality disorders are there?
There are four types: antisocial personality disorder, borderline personality disorder, histrionic personality disorder, and narcissistic personality disorder.
What is antisocial personality disorder (ASPD)?
People diagnosed with ASPD show a lack of respect toward others and generally don't follow socially accepted rules.
What is borderline personality disorder (BPD)?
People diagnosed with BPD have difficulty regulating their emotions. This results in low self-esteem, mood swings, and impulsive behaviors.
What is histrionic personality disorder (HPD)?
People diagnosed with HPD have intense, unstable emotions and a distorted self-image. They have an overwhelming desire for others to notice them and are easily influenced by others.
What is narcissistic personality disorder (NPD)?
People diagnosed with NPD have a sense of being better than others, an intense need for praise, and a lack of empathy for others.
What traits do Cluster B personality disorders share?
In general, the traits include being dramatic or overly emotional, impulsiveness, unpredictable or erratic behavior, and difficulty keeping stable relationships.
Do people with Cluster B PDs know their behavior is problematic?
Often, no. As with many other personality disorders, people living with Cluster B PDs often don't realize there's an issue with their behavior.
What causes Cluster B personality disorders?
Healthcare providers aren't sure of the exact cause. Research suggests it's complex and may involve many factors, from genetics to certain experiences you had growing up.
Are childhood experiences linked to Cluster B PDs?
Yes. Adverse childhood experiences (ACEs) are especially linked to Cluster B PDs. They include physical and sexual abuse, emotional abuse, neglect, and household issues like divorce, money difficulties, and parental mental health conditions.
What complications are people with Cluster B PDs at higher risk for?
Compared to other personality disorder clusters, they are at increased risk of substance use disorders (like alcohol use disorder), suicidal thoughts and attempts, and crime (especially those with antisocial personality disorder).
Are other mental health conditions common with Cluster B PDs?
Yes. As with other PDs, people living with Cluster B PDs are more likely to be diagnosed with mood and/or anxiety disorders as well.
How are Cluster B personality disorders diagnosed?
Healthcare providers use criteria in the American Psychiatric Association's DSM-5. Each PD type has specific criteria, and providers ask about medical, personal, and social history to guide diagnosis.
Why can diagnosis be difficult?
Most people living with these conditions may not seek treatment, often due to community mental health stigma or a lack of insight into their behaviors. Mental health professionals may work with loved ones and acquaintances to gather more information.
How are Cluster B personality disorders treated?
Psychotherapy (talk therapy) with a mental health professional like a psychologist can help you manage the condition, learn healthier ways of navigating emotions and relationships, and provide support, education, and guidance to you and your family.
What type of therapy works best for borderline personality disorder?
Dialectical behavior therapy (DBT) tends to be a more effective treatment for BPD.
What type of therapy works best for histrionic personality disorder?
People with HPD often benefit from cognitive-behavioral therapy (CBT).
Are there medications for Cluster B personality disorders?
Currently, there are no FDA-approved medications to treat PDs directly. But you may take medications to treat symptoms of other mental health conditions you may have, like depression and anxiety.
What is the outlook for someone with a Cluster B personality disorder?
The outlook varies. It depends on your willingness to get treatment and how severe your symptoms are. With treatment, it's possible to improve your behaviors, thinking patterns, and quality of life.
What happens if a Cluster B personality disorder goes undiagnosed and untreated?
It may result in poor relationships (including a lack of stable, healthy partner and friend relationships), work issues, and problems with social functioning — including inaccurately understanding and responding to others' emotional cues and boundaries.
Can someone with a Cluster B PD improve with treatment?
Yes. With treatment, it's possible to improve behaviors, thinking patterns, and quality of life. Seeking help as soon as symptoms appear can decrease the disruptions to your life.
What should loved ones of people with Cluster B PDs do?
Loved ones can experience stress, depression, grief, and isolation. Reach out for help if you have these symptoms.
Can mental health professionals customize treatment?
Yes. Mental health professionals can design tailored treatment plans that can help you better manage your thoughts and behaviors.
Related Reading
References
Cleveland Clinic. Cluster B Personality Disorders. Cleveland Clinic. Last updated November 4, 2025. https://my.clevelandclinic.org/health/diseases/cluster-b-personality-disorders
Broekhof R, Nordahl HM, Eikenæs IU, Selvik SG. Adverse Childhood Experiences Are Associated With Personality Disorder: A Prospective, Longitudinal Study. J Pers Disord. 2024;38(1):19-33. PMID 38324247. https://doi.org/10.1521/pedi.2024.38.1.19
Fariba KA, Gupta V, Torrico TJ, Kass E. Personality Disorder. StatPearls (NCBI Bookshelf). Last update July 17, 2024. PMID 32310518. https://www.ncbi.nlm.nih.gov/books/NBK556058/
Massaal-van der Ree LY, Eikelenboom M, Hoogendoorn AW, et al. Cluster B versus Cluster C Personality Disorders: A Comparison of Comorbidity, Suicidality, Traumatization and Global Functioning. Behav Sci (Basel). 2022;12(4):105. PMID 35447677. https://doi.org/10.3390/bs12040105
Turner D, Sebastian A, Tüscher O. Impulsivity and Cluster B Personality Disorders. Curr Psychiatry Rep. 2017;19(3):15. PMID 28251591. https://doi.org/10.1007/s11920-017-0768-8
Zimmerman M. Overview of Personality Disorders. Merck Manual Professional Version. Last updated January 2026. https://www.merckmanuals.com/professional/psychiatric-disorders/personality-disorders/overview-of-personality-disorders
Medical disclaimer
This article is for general informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. If you are experiencing suicidal thoughts or a mental health emergency, contact emergency services or a crisis hotline immediately. Never disregard professional medical advice or delay seeking it because of something you have read here. Individual treatment decisions should always be made with your healthcare team.
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