The term personality is used to describe the innate and enduring characteristics of an individual which shape their attitudes, thoughts and behaviors in response to situations. When these enduring traits of an individual are the cause of distress or difficulties for them as a person or in their relationships with others then it can be said that they are suffering from a personality disorder. A clinical diagnosis of personality disorder should be based on an accurate assessment of a person's pervasive pattern of functioning. It is also crucial that these pathological personality traits should appear before young adulthood. Based on clinical presentation, personality disorders can be classified into three different categories: A, B and C. Group A consists of paranoid, schizoid and schizotypal personality disorder. Individuals from group B are usually seen as dramatic, overly sensitive or fickle. Narcissistic, antisocial, borderline and histrionic personality disorder are included in this group. Group C is composed of dependent, avoidant and obsessive-compulsive personality disorder. Narcissistic individuals are lead by a feeling of superiority and the need for admiration, but they are also extremely sensitive to critique and failure. Antisocial personalities are manipulative, egocentric and prone to criminal behavior. Borderline personality disorder is characterized by a severely unstable self-concept and intense interpersonal relationships. Histrionic individuals have a constant need to be the center of attention which they accomplish by acting and dressing themselves in a provocative way. Throughout history personality disorders have been of great interest to a wide variety of people, including writers. Characters with such traits have for a long time served as key plot points, whether it be due to their eccentric behavior, intense relationships with other characters or because of their excessive emotional responses to situations.