What Are Cluster B Personality Disorders?

Medically Reviewed by Dan Brennan, MD on November 27, 2021
4 min read

Cluster B disorders are a collection of personality disorders that affect how people behave. People with cluster B personality disorders are more likely to behave dramatically and erratically. They may seem like they need much more or much less attention than other people. 

Here’s what you need to know about cluster B disorders. 

A personality disorder is a mental disorder that’s caused by an unhealthy pattern of thought and behavior. People with personality disorders often struggle to interact with the world. Their disorder makes it hard for them to understand social situations and relationships.

Clusters A and C. There are several “clusters” of personality disorders. Each cluster has different symptoms in common. Cluster A disorders are defined by “odd” thinking and behaviors like paranoia or a lack of emotional responses. Cluster C disorders are defined by anxious thoughts and behavior. 

Cluster B. Cluster B disorders involve unpredictable, dramatic, or intensely emotional responses to things. The four main cluster B disorders are:

  • ‌Antisocial
  • ‌Borderline
  • ‌Histrionic
  • ‌Narcissistic

Each of these disorders has a specific pattern of behavior. People with these disorders often feel like they need attention constantly. It’s also common for them to occasionally show symptoms of at least one other personality disorder.

Not everyone who has strong emotional responses or dramatic behavior has a cluster B disorder. The International Statistical Classification of Diseases and Related Health Problems (ICD-10) states that a pattern of behavior is only a personality disorder if it bothers the person or causes them to struggle in many normal situations. 

Some people with cluster B disorders may not realize that their behavior is the cause of their unhappiness. Cluster B disorders can be treated with therapy and occasionally with medication. 

But the person in treatment needs to understand why they are being treated for it to work. Certain people with cluster B disorders avoid treatment because they don’t think anything is wrong with their behavior.

Antisocial meaning. “Antisocial” doesn’t mean that people with this disorder avoid talking to others. Instead, it describes how they often break social and legal rules to get what they want. They are against society, or “antisocial”.

If you have antisocial personality disorder, you tend to ignore other people’s feelings and authority. You usually focus on yourself and your own goals without caring about anyone else.

Other symptoms of antisocial personality disorder include:

  • ‌Aggressiveness
  • ‌Impulsiveness
  • ‌Lack of remorse
  • ‌Frequent problems with the law
  • ‌Disregard for safety
  • ‌Persistent lying
  • Consistent irresponsible behavior

People with borderline personality disorder have a weak sense of self-worth. They rely on other people in their lives to help them feel stable. They often have inconsistent moods that flip from very positive to very negative without a clear cause.

BPD and self-worth. With BPD, you place your self-worth in your relationships. You may manipulate other people to keep them from leaving. This condition often leads you to have “favorite people”. 

You may idolize your favorite person until they do something wrong. That flips your opinion and you’ll then cut off your former friend.

Other symptoms of borderline personality disorder include:

  • Deep fear of loneliness
  • ‌Frequent displays of anger
  • ‌Feelings of emptiness‌
  • Unstable relationships
  • ‌Impulsiveness
  • ‌Black and white thinking
  • ‌Risk-seeking behavior such as gambling or unsafe sex
  • ‌Suicidal threats

People with histrionic personality disorder want attention all the time and actively seek it out. With this disorder, they’ll usually be very aware of how they look all the time. They behave in exaggerated ways and may seem “over-the-top”.

Overreacting. If you have HPD, you may overreact to small events. You might appear to be fine one moment and then burst into tears when you’re told you can’t do something. You may also have trouble maintaining relationships because of how you act.

Other symptoms of histrionic personality disorder include:

  • ‌Strong opinions without actual knowledge
  • ‌Dramatic behavior
  • ‌A constant need for attention
  • ‌Shallow emotions that change quickly
  • ‌Suggestibility

People with narcissistic personality disorder generally believe that they are better than others. They don’t simply have high self-esteem, but actively believe that they are more important than other people and should be treated that way. Many people with this disorder react badly to criticism or events they dislike.

Manipulation. If you have NPD, you’re more likely to try to take advantage of people by manipulating them. You may have an overly emotional response if you don’t receive the attention you feel you deserve. You may also overreact to situations to keep people focused on you.

Other symptoms of narcissistic personality disorder include:

  • ‌Arrogance
  • ‌Envy
  • ‌Expectation for praise
  • ‌Expectation of favors
  • ‌Fantasies of power or success
  • ‌No acknowledgment of others’ successes