A personality disorder is a deep-rooted, fixed, and dysfunctional pattern of thinking, feeling, and behaving that interferes with an individual's ability to maintain healthy relationships in personal, social, or work-related situations. A personality disorder typically starts to become apparent during late adolescence or early adulthood.

​

There are 10 formally recognized personality disorders that fall into three clusters; typically there is overlap between the disorders:

​

Cluster A is characterized by odd or eccentric thinking or behavior. This cluster includes paranoid, schizoid, and schizotypal personality disorders; people with these disorders demonstrate the following behaviors:  

• Paranoid Personality Disorder: distrustful and suspicious; belief that others are out to get them; socially detached or isolated; argumentative 

• Schizoid Personality Disorder: disinterest in others; tend to be loners; limited emotional expression.

• Schizotypal Personality Disorder: odd or bizarre behavior or ideas; anxiety in social situations

Cluster B is characterized by appearing emotional, dramatic, and unpredictable. This cluster includes borderline, narcissistic, histrionic, and antisocial personality disorders; people with these disorders demonstrate the following behaviors:  

​

• Borderline Personality Disorder: intense emotional reactions; impulsivity; stormy relationships; highly changeable moods

• Histrionic Personality Disorder: attention seeking; overly dramatic; suggestible 

• Narcissistic Personality Disorder: lack of empathy for others; excessive need for admiration; grandiose sense of self-importance; sense of entitlement 

• Antisocial Personality Disorder: manipulative and deceitful behavior; complete disregard for others

Cluster C is characterized by appearing anxious or fearful. This cluster includes avoidant, dependent, and obsessive-compulsive personality disorders; people with these disorders demonstrate the following behaviors: 

​

• Avoidant Personality Disorder: sensitivity to rejection; shy or inhibited around others; easily hurt

• Dependent Personality Disorder: difficulty being alone; fear of abandonment; overly reliant on others; submissive behavior

• Obsessive-Compulsive Personality Disorder: rigid adherence to rules; excessive need for orderliness and control (with no room for flexibility), perfectionism