Personality Disorder - Diagnosis

Diagnosis

The DSM-IV lists General diagnostic criteria for a personality disorder, which must be met in addition to the specific criteria for a particular named personality disorder. This requires that there be (to paraphrase):

• An enduring pattern of psychological experience and behavior that differs prominently from cultural expectations, as shown in two or more of: cognition (i.e. perceiving and interpreting the self, other people or events); affect (i.e. the range, intensity, lability, and appropriateness of emotional response); interpersonal functioning; or impulse control.
• The pattern must appear inflexible and pervasive across a wide range of situations, and lead to clinically significant distress or impairment in important areas of functioning.
• The pattern must be stable and long-lasting, have started as early as at least adolescence or early adulthood.
• The pattern must not be better accounted for as a manifestation of another mental disorder, or to the direct physiological effects of a substance (e.g. drug or medication) or a general medical condition (e.g. head trauma).

The ICD-10 'clinical descriptions and diagnostic guidelines' introduces its specific personality disorder diagnoses with some general guideline criteria that are similar. To quote:

• Markedly disharmonious attitudes and behavior, generally involving several areas of functioning; e.g. affectivity, arousal, impulse control, ways of perceiving and thinking, and style of relating to others;
• The abnormal behavior pattern is enduring, of long standing, and not limited to episodes of mental illness;
• The abnormal behavior pattern is pervasive and clearly maladaptive to a broad range of personal and social situations;
• The above manifestations always appear during childhood or adolescence and continue into adulthood;
• The disorder leads to considerable personal distress but this may only become apparent late in its course;
• The disorder is usually, but not invariably, associated with significant problems in occupational and social performance.

The ICD adds: "For different cultures it may be necessary to develop specific sets of criteria with regard to social norms, rules and obligations."

In clinical practice, individuals are generally diagnosed by an interview with a psychiatrist based on a mental status examination, which may take into account observations by relatives and others. One tool of diagnosing personality disorders is a process involving interviews with scoring systems. The patient is asked to answer questions, and depending on their answers, the trained interviewer tries to code what their responses were. This process is fairly time consuming.