Personality disorders are a form of mental disorder. They are characterised by a long-term pattern of serious behavioural differences that significantly affect the functioning of the individual in personal and social situations. Personality disorders are represented on Axis II of the DSM-IV, and are particularly controversial because they often seem sexist, and because their comorbidity rate is excessively high, indictative of poor categorization.

The ten types of personality disorders that have been defined are:

Cluster A (odd or eccentric disorders)

Cluster B (dramatic, emotional, or erratic disorders) Cluster C (anxious or fearful disorders)