Differences Between Cluster A, B and C Personality Disorder Types

It’s important to address a personality disorder and seek treatment. Generally influenced by a combination of genetics, environment and brain chemistry, personality disorders can disrupt a person’s life, as well as the lives of friends and family. These disorders can lead to dysfunction in daily life, as well as self-harming behaviors such as substance abuse that are used as an unhealthy way to cope.

Personality disorders aren’t simply a matter of having a bad day. There are 10 personality disorders and each one has several traits that are common to it that don’t go away or change under different circumstances. To be considered as having a personality disorder, a person must exhibit a certain number of those traits consistently over a period of time—and those behaviors must be so pervasive that the person is prevented from carrying out normal activities or suffers great affliction because of them.

Because certain disorders share similar traits with others, and because some disorders even co-occur, they have been put into groups together. Cluster personality disorders are organized into three categories: Cluster A, Cluster B and Cluster C.

An Explanation of Cluster Personality Disorders

Cluster A is made up of paranoid, schizoid and schizotypal personality disorders. These disorders are generally marked by difficult social interaction and thoughts that don’t conform to reality.

Paranoid personality disorder: This disorder makes someone suspicious of other people, and that mistrust can affect social relationships. Feeling persecuted and attacked, the person may isolate himself from others, act defensively or preemptively attack others without apparent cause. There may also be a hostile attitude because the paranoia causes the person to take harmless comments and twist them to give them a negative slant.

Schizotypal personality disorder: Distorted thought is also a hallmark of this disorder, but generally more intense. Someone with this disorder may start to believe their thoughts are either all-powerful and can affect people, or the thoughts can be held captive by others. Some people start to hear voices or see things others can’t, attaching significant meaning to them. This kind of thinking can manifest itself in uncomfortable social interaction and odd ways of expressing one’s behavior, thoughts or emotions.

Schizoid personality disorder: Someone with this disorder is likely to isolate socially, finding little happiness in developing close relationships, or even in normal life in general. Seen as a loner, the person may act aloof or detached from daily life, and is considered someone who has little emotional expression and can’t engage with others.

Cluster B personality disorders are on the other end of the spectrum from Cluster A’s limited emotional expression. Narcissistic, histrionic, antisocial and borderline personality disorders are considered highly emotional and dramatic, while at the same time being extremely unpredictable.

Antisocial personality disorder: An antisocial person will completely dismiss and disregard another person’s thoughts and feelings, often on a level that can be aggressive and hostile. They generally aren’t sorry if they cause harm to anyone or anything, and tend to refuse to take responsibility for their actions. Antisocial personality disorder can also lead someone to impulsively participate in risky situations, regardless if it poses a danger to themselves or others.

Histrionic personality disorder: As the name of this disorder implies, excessive emotion is the defining characteristic. Someone with this disorder craves drama in life, especially if it keeps him at the center of attention, which is where he wants to belong. There can be a certain flamboyance in his interactions with others, but while the intensity of emotions can be strong, the depth of them may be more shallow and insincere—anything to keep the attention. When someone with this disorder doesn’t get that focused attention, he can be depressed and it can cause problems in relationships.

Narcissistic personality disorder: The disorder deludes sufferers into thinking they are powerful, special and above everyone else. That breeds an arrogance that can destroy relationships with other people. There can be a driving need to seek success and glory at all costs, and when they feel others don’t perceive them as special, it can be crushing.

Borderline personality disorder: This disorder is characterized by instability in mood and behavior. Even a person’s perception of himself isn’t stable, and generally there is no in- between state—he is either a saint or rotten to the core. This instability can result in dizzying emotional swings, from anger to loneliness to emptiness, and impulsive behavior. To counteract this, someone with borderline personality disorder may be tempted to indulge in unsafe behavior, such as substance abuse, as a way to regulate or medicate themselves.

Cluster C personality disorders are focused on anxiety and fear. This cluster consists of avoidant, dependent and obsessive-compulsive personality disorders.

Avoidant personality disorder: This disorder can be crippling, as it triggers the belief in someone that he isn’t good enough or well liked. This sense of inadequacy can lead to limited social engagement and a fear of negative criticism, or any behavior that will avoid feelings of rejection.

Dependent personality disorder: On the other hand, someone with this disorder desperately needs to be around others, especially those who are seen as caretakers. In order to not jeopardize these relationships, the person can become too clingy and sublimate their own values, emotions and thoughts. Independence takes a back seat and conflict is to be avoided at all costs.

Obsessive-compulsive personality disorder: A person with this disorder is consumed with a rigid sense of propriety and regulation, and perfectionism is expected. There is a risk that he will be so focused on tasks and schedules that everything else—relationships, hobbies, happiness—will fall by the wayside. Interactions with others can be marked with stubborness and a “my way or the highway” attitude that can drive people away. Control over things such as job duties or money must always be maintained, no matter the cost.

If you or someone you love is grappling with the effects of a personality disorder, it’s crucial to get help. Casa Palmera can expertly work with people suffering from all types of cluster personality disorders, as well as any co-occurring issues such as substance abuse. If you are seeking high-quality, compassionate residential care in a healing environment, contact Casa Palmera today.


This blog is for informational purposes only and should not be a substitute for medical advice. We understand that everyone’s situation is unique, and this content is to provide an overall understanding of substance use disorders. These disorders are very complex, and this post does not take into account the unique circumstances for every individual. For specific questions about your health needs or that of a loved one, seek the help of a healthcare professional.