Cluster A, B, and C Personality Disorders


There are numerous personality disorders that exist, all of which are neatly categorized as being either “Cluster A, B, or C personality disorders.” Each of these categories or clusters are just as unique as the personality disorders themselves. Below, you will see how each illness is categorized, as well as what their respective symptoms are and how personality disorders in general are caused and treated.

Cluster A Personality Disorders

Cluster A personality disorders are characterized by odd, eccentric thinking or behavior. They include paranoid personality disorder, schizoid personality disorder, and schizotypal personality disorder.

Paranoid Personality Disorder

  • Distrust of most people, even loved ones

  • Difficulty having healthy relationships with others

  • Belief they are being stalked when they are not

  • Belief they are being persecuted when they are not

  • Looking for clues merely to validate their false beliefs

  • Stress and anxiety due to their paranoia

Schizoid Personality Disorder

  • Appearance of being cold or indifferent to others

  • Lack of interest in relationships, preferring to be alone

  • Inability to take pleasure in most activities

  • Inability to pick up normal social cues

  • Having a limited range of emotional expression

  • Little or no interest in having sex with another person

Schizotypal Personality Disorder

  • Behavior or appearance that is odd, eccentric, or peculiar

  • Poor rapport with others and a tendency to withdraw socially

  • Odd beliefs or magical thinking, influencing behavior and inconsistent with subcultural norms

  • Suspiciousness or paranoid ideas

  • Vague, circumstantial, metaphorical, overelaborate, or stereotyped thinking, manifested by odd speech or in other ways, without gross incoherence

  • Unusual perceptual experiences including somatosensory (bodily) or other illusions, depersonalization or derealization

Cluster B Personality Disorders

Cluster B personality disorders are characterized by dramatic, overly emotional, or unpredictable thinking or behavior. They include antisocial personality disorder, borderline personality disorder, histrionic personality disorder, and narcissistic personality disorder.

Antisocial Personality Disorder

  • Lack of empathy for others

  • No conscience

  • Disregard for right or wrong

  • Arrogance and very opinionated

  • Using charm to manipulate others

  • Impulsive behavior

  • Recurring problems with the law

  • Hostility and aggressiveness

  • Financially irresponsible

Borderline Personality Disorder

  • Intense mood swings

  • Low self-worth

  • Relationship problems

  • Impulsive behavior

  • Fear of abandonment

  • Hurting oneself

Histrionic Personality Disorder

  • Needing to be the center of attention

  • Easily influenced by others

  • Constantly seeking approval

  • Being overly dramatic and emotional

  • Making rash decisions

  • Tendency to believe that relationships are more intimate than they really are

  • Overly concerned with physical appearance

  • Blaming personal failures and disappointments on others

Narcissistic Personality Disorder

  • Exaggerates about accomplishments, possessions, earnings, intelligence, etc.

  • Manipulative

  • Believing they are better than other people, arrogant

  • Power seeking

  • Lacking empathy

  • Craves admiration and attention from other people

  • Are very envious of other people’s possessions, accomplishments, etc.

  • Believing that people are very envious of them, even if they have not accomplished much

  • Heavily criticizes others, yet are unwilling to be criticized themselves

Cluster C Personality Disorders

Cluster C personality disorders are characterized by anxious, fearful thinking or behavior. They include avoidant personality disorder, dependent personality disorder, and obsessive-compulsive personality disorder.

Avoidant Personality Disorder

  • Low self-esteem

  • Feels socially inept

  • Self-isolation

  • Hesitance to get involved with people

  • Preoccupied with being criticized or rejected

  • No close friends

  • Exaggeration of difficulties

  • Unwilling to take risks

Dependent Personality Disorder

  • Easily hurt by criticism

  • Inability to cope with the demands of life

  • Avoiding being alone

  • Inability to accept disagreements

  • Difficulty making decisions without other’s approval

  • Acceptance of being mistreated

  • Extreme passivity

  • Completely devastated when relationships end

Obsessive-Compulsive Personality Disorder

  • Excessive pursuit for perfection and orderliness

  • Maintaining a “It’s never good enough” attitude

  • Being very inflexible and close-minded

  • Highly stressed and anxious when “perfecting” things

  • Workaholic behavior

  • Deep desire to control themselves and their environment

  • May find it very difficult to relax

Causes of Personality Disorders

Although not completely understood, it is believed that personality disorders are likely caused by a combination of genetic factors and environmental factors. People with a family history of mental illness, especially of personality disorders will likely have a higher chance of developing one themselves insofar as they have a genetic predisposition to develop mental illness that is.

Common Treatments

There are many different types of treatment methods available for people suffering from personality disorders. The specific methodology used will depend on what their specific personality disorder is, as well as if there are any additional mental illnesses which are simultaneously occurring alongside their personality disorder.

Psychotherapy and psychiatric medication may be the best ways to treat personality disorders. However, this will strongly depend upon the recommendations of one’s psychiatrist/therapist as they work with the patient to minimize as many symptoms of their mental illness as possible.

As is the case with virtually every other mental illness, personality disorders are lifelong mental illnesses that usually require some form of treatment for the entirety of one’s life. However, this will inevitably depend on how severe their condition is, as well as their genetics, among many other factors.


Mayo Clinic