There are ten different types of personality disorders. The most well-known is Borderline Personality Disorder. Personality disorders usually begin when people are teenagers or young adults and remain throughout life.

Personality disorders are chronic, enduring patterns of thinking, feeling and behaving that affect a person’s ability to function in everyday activities, especially work, family, and social life. There are biological and psychological parts to most personality disorders. The preferred treatment is psychotherapy, although medication may be needed to treat serious symptoms.

The ten personality disorders are currently grouped into three clusters based on similarities, although research is occurring on a dimensional perspective that personality disorders represent maladaptive variants of personality traits that merge into normality and into one another.

Cluster A includes the Paranoid, Schizoid, and Schizotypal Personality Disorders. People with these disorders often appear odd or eccentric. Cluster B includes the Antisocial, Borderline, Histrionic, and Narcissistic Personality Disorders. Individuals with these disorders often appear dramatic, emotional or erratic. Cluster C includes the Avoidant, Dependent, and Obsessive-Compulsive Personality Disorders. People with these disorders often appear anxious or fearful.

It is believed that 5.7% have Cluster A disorders, 1.5% have Cluster B disorders, and 6% have Cluster C disorders. It is estimated that about 15% of U.S. adults have at least one personality disorder.