Section Learning Objectives

• Describe the criteria for being diagnosed with a personality disorder.
• Describe the symptoms associated with each cluster of personality disorders.
• Indicate which cluster each of the 10 personality disorders belongs to.

9.1.1 Overview 

In order to be diagnosed with any personality disorder, the individual must exhibit a pervasive and long-lasting pattern of inner experience and inflexible behavior that violates cultural norms and is manifested in at least two of the following four areas: distorted thinking patterns (cognition), problematic emotional responses (affect), over- or under-regulated impulse control, and interpersonal difficulties.  The pattern of behavior or inner experience must persist since adolescence or early adulthood and must result in significant distress or impairment. Without distress or impairment, the pattern should be considered a personality trait rather than a disorder. While these features are common among all ten personality disorders, the DSM-5 divides personality disorders into three different clusters based on symptom similarities.

9.1.2 Cluster A 

Cluster A is described as the odd/eccentric cluster and consists of paranoid personality disorder, schizoid personality disorder, and schizotypal personality disorder. The common feature of these three disorders is social awkwardness and social withdrawal (APA, 2013). Often these behaviors are similar to those seen in schizophrenia.  In fact, cluster A personality disorders are more common among individuals who have a relative diagnosed with schizophrenia (Chemerinksi & Siever, 2011). However, the symptoms of cluster A personality disorders tend to be less extensive and less impactful on daily functioning relative to those experienced by individuals with schizophrenia.

9.1.3 Cluster B 

Cluster B is typically described as the dramatic, emotional, and/or erratic cluster and consists of antisocial personality disorder, borderline personality disorder, histrionic personality disorder, and narcissistic personality disorder. Individuals with these personality disorders often experience problems with impulse control and emotional regulation (APA, 2013). Due to the dramatic, emotional, and erratic nature of these disorders, it is very difficult for individuals with these disorders to establish healthy relationships with others.

9.1.4 Cluster C 

Cluster C is characterized as the anxious/fearful cluster and consists of avoidant personality disorder, dependent personality disorder, and obsessive-compulsive personality disorder. As you read through the descriptions of these disorders, you will see overlaps with symptoms of anxiety and depressive disorders. Likely due to the similarity in symptoms with psychological disorders that have effective treatment options, cluster C disorders have the most treatment options of all personality disorders.

It should be noted that this clustering system is useful in academic settings (research, education) but is known to be limited and to have issues with validity. For example, it is not uncommon for people to have comorbid personality disorders from different clusters or to have various traits from several clusters.