Cluster B personality disorders
AssessmentsCluster B personality disorders
Cluster B personality disorders
USMLE® Step 1 style questions USMLE
A 45-year-old man comes to the office for a routine physical examination. After waiting an hour, he begins to berate the receptionist and demands to be seen by a doctor. He says that other patients in the waiting room had tried to engage him in a conversation about their own problems. He says, “My health is far more important than their health! After all, I am the owner of a multinational bank!” During the visit, the patient expresses irritation in having to take the time out of his busy schedule and is under a lot of stress lately. The patient talks about feeling depressed because of multiple failed relationships, even though he is a “great romantic.” He recently broke up with his partner because they canceled a plan with him in order to visit their parents after their grandmother’s death. Past medical and family history is noncontributory. Temperature is 37°C (98.6°F), pulse is 81/min, respirations are 14/min, and blood pressure is 129/80 mm Hg. Physical examination shows no abnormalities. Which of the following is the best explanation for this patient’s behavior?
Content Reviewers:Rishi Desai, MD, MPH
Contributors:Tanner Marshall, MS
If you were asked to describe a friend’s personality, you might describe them as generally being a creative type, or easy-going but nervous in groups.
Basically, you’re trying to summarize the personal traits that make them who they are—either how they think or how they act.
Sometimes these thought patterns or behaviors which make up a person’s personality can actually be harmful in the sense that they interfere with their day-to-day functioning in their personal life, at work, or in social settings.
If this were the case, we would say that the individual has a personality disorder.
The DSM-5, or the diagnostic and statistical manual for mental disorders, the 5th edition, lists ten personality disorders that are split into three different ‘clusters’, referred to as clusters A, B, and C.
These used to be under the category “Axis 2” but that way of organizing isn’t really used anymore.
Cluster B includes antisocial personality disorder, borderline personality disorder, histrionic personality disorder, and narcissistic personality disorder.
All four of these have a genetic relationship with mood disorders- like depression and bipolar disorder, as well as substance use disorders.
Okay, so antisocial personality disorder—this sounds like they don’t get along well with others, but in fact, it’s the opposite, they can be really charming and often use that to manipulate others for their personal gain.
These individuals disregard moral values and societal norms, have little empathy, and poor impulse control.
This combination makes them willing to hurt others if it helps them, making them prone to aggressive and unlawful behavior, at times earning the label sociopath or psychopath.
In fact, individuals with this disorder tend to be overrepresented in prison populations and have higher rates of substance use.
These individuals typically fail to show remorse or guilt and rarely accept responsibility for any of the harm that they cause others.
This disorder is also unique in that individuals must be over 18 years old and have a history of conduct disorder in order to meet the diagnosis.
Next up is borderline personality disorder which is where individuals have unstable moods.
They go from intense joy one minute to rage the next minute; this leads to intense, sometimes wonderful relationships that generally become dramatic and sour over time.
This pattern is sometimes called stable instability, because the only consistent thing is instability.
These people often use a defense mechanism called splitting where people and important things, like a job, are seen as either completely good or completely bad.