personality disorders

Meaning: A personality disorder is a long-standing pattern that is rigid across many situations, begins by adolescence or early adulthood, and causes distress or impairment. People often experience the pattern as just part of who they are. The DSM groups ten disorders into clusters. Cluster A (odd, eccentric): paranoid, schizoid, schizotypal. Cluster B (dramatic, emotional, erratic): antisocial, borderline, histrionic, narcissistic. Cluster C (anxious, fearful): avoidant, dependent, obsessive-compulsive.

On the MCAT: A vignette describes a person's lifelong pattern, and you name the cluster or disorder. Typical cues: disregard for others' rights and deceit point to antisocial; unstable relationships, fear of abandonment, and impulsivity point to borderline; grandiosity and need for admiration point to narcissistic; distrust and suspicion point to paranoid; detachment and a narrow range of emotion point to schizoid; odd beliefs and magical thinking point to schizotypal; fear of rejection with social withdrawal points to avoidant. Questions may also contrast these stable traits with episodic disorders such as major depression.

Common confusion: Cluster A disorders are not schizophrenia. Schizotypal personality disorder involves odd beliefs and behavior, but sustained psychosis is not its defining feature. Likewise, obsessive-compulsive personality disorder is not OCD. The personality disorder is a pervasive preoccupation with order, perfectionism, and control that the person usually sees as reasonable. OCD involves intrusive obsessions and repetitive compulsions that the person finds distressing.