DSM-IV-TR: The Ten Personality Disorders: Cluster C
Cluster C: The Anxious, Fearful Cluster
Cluster C includes the Avoidant, Dependent, and Obsessive-Compulsive Personality Disorders. These three personality disorders share a high level of anxiety.
The Avoidant Personality Disorder* is characterized by anxiety about everyday social situations and by social inhibition. The main feature of this disorder is a chronic sense of inferiority and inadequacy. People with this disorder are intensely afraid that others will ridicule them, reject them, or criticize them. This leads them to avoid social situations and to avoid interactions with others, which further limits their ability to develop social skills. People with Avoidant Personality Disorders often have a very limited social world with a small circle of confidants; but, an otherwise rather limited social life.
The core feature of the Dependent Personality Disorder* is a strong need to be taken care of by other people. This need to be taken care of, and the associated fear of loosing the support of others, often leads people with Dependent Personality Disorder to behave in a "clingy" manner; to submit to the desires of other people; and they may have great difficulty standing up for themselves. They find it difficult to express disagreement or make independent decisions, and are challenged to begin a task when nobody is available to assist them. Being alone is extremely hard for them. When someone with Dependent Personality Disorder finds that a relationship they depend on has ended, they will immediately seek another source of support.
Persons with Obsessive-Compulsive Personality Disorder* are preoccupied with rules, regulations, and orderliness. They are great makers of lists and schedules, and are often devoted to work to such an extent that they often neglect social relationships. They have perfectionist tendencies, and are so driven in their work to "get it right" that they become unable to complete projects or specific tasks because they get lost in the details, and fail to see the "forest for the trees." Persons with Obsessive-Compulsive Personality Disorder tend to be rigid and inflexible in their approach to things. It simply isn't an option for them to do a "sub-standard" job just to get something done. Often, they are unable to delegate tasks for fear that another person will not "get it right."
*The above list only briefly summarizes these individual Cluster C personality disorders. Richer, more detailed descriptions of these disorders are found in the section describing the four core features of personality disorders.