The Role of MMPI-2 in Assessment of Chronic Pain

The Minnesota Multiphasic Personality Inventory (MMPI-2) data is best viewed as one of multiple sources of patient information, including history, social support networks, coping ability, job, and life satisfaction/success, etc.
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The Minnesota Multiphasic Personality Inventory-2 (MMPI-2) is one the most widely used personality assessment instruments in the world1 and arguably the most widely used psychological instruments to study chronic pain.2 The MMPI was developed by Starke Hathaway and J. C. McKinley in 1943 to aid in the diagnosis of psychiatric disorders; it was subsequently revised in 1989 to address several issues related to the normative data and outdated language.1 Hathaway and McKinley initially used an empirical keying approach, in which test constructors selected items based on whether the items could differentiate members of a “normal” group—presumably free of psychopathology—from members of a “criterion” group, where individuals had a certain psychiatric diagnosis. The “normal” group consisted of, but was not limited to, visitors to, and relatives of, patients at the University of Minnesota Hospital. The clinical groups consisted of patients in eight psychiatric diagnostic categories:

  • hypochondriasis
  • depression
  • hysteria
  • psychopathic deviate
  • paranoia
  • psychasthenia
  • schizophrenia
  • hypomania

A Masculinity-Femininity Scale and a Social Introversion Scale were added later and were based on non-clinical patients.1

Essentially, the MMPI-2 consists of a set of 3 main validity scales, 10 standard scales, sometimes referred to as clinical scales, and numerous supplemental and subscales. A patient’s score on each of these scales is compared to a normative sample, which roughly coincides with the demographic characteristics of the United States. Raw scores are then transformed into T-scores. Scales that exceed a T-score of 65 (1.5 standard deviations above the mean of 50) are considered clinically significant. Literally hundreds of validity studies have established the interpretive meanings of various clinical scale configurations.1 It should also be noted that there is a computerized scoring and interpretation system currently available (Pearson Assessments). Table 1 summarizes the 3 main validity and 10 main clinical scales of the MMPI-2.

Common MMPI-2 Scales Associated with Chronic Pain

Individual Scales. The first three clinical scales (hypochondriasis , depression, and hysteria) are the most relevant for medical patients and have been the most widely investigated with pain patients.3 McKinley and Hathaway defined Scale 1 (hypochondriasis ) as an abnormal concern over health. When the MMPI was constructed, subjects in the “clinical” group consisted of individuals who were excessively concerned with possible ailments that were believed to have limited or no organic basis. Elevated scores on Scale 1 suggest the possibility of numerous somatic complaints, selfishness, immaturity, and narcissism.4

The clinical group for Scale 2 (depression) consisted mostly of bipolar (manic-depressive) patients during a depressive episode. Although many individuals with elevations on Scale 2 are depressed, an individual can display an elevated Scale 2, but not meet criteria for a Major Depressive Disorder. Rather, this scale may be thought of as a measure of distress and, when it becomes increasing elevated, suggests the possible presence of depression. Individuals with an elevated Scale 2 tend to be unhappy, pessimistic, self-deprecating, and sluggish.4

Scale 3 (hysteria) was intended for the detection and diagnosis of Conversion hysteria. Hathaway and McKinley used 50 patients with a clinical diagnosis of psychoneurosis, most of whom were believed to have a conversion disorder.2 Butcher and Williams describe patients with a conversion disorder as exhibiting personalities characterized by denial and flamboyant social interactions. These individuals may react to stress with the development of a physical complaint.3 The original understanding of a conversion reaction was believed to be related to a metaphorical resolution of an intrapsychic conflict (primary gain) that may be reinforced by attention or the removal of undesired responsibilities because of the physical problem (secondary gain). Although individuals with an elevated Scale 3 tend to react to stress with physical symptoms, they often have limited insight into their feelings and motivations.2,3 Further, these individuals may frequently need approval and attention from others.2 Elevations on this scale may reflect a difficulty acknowledging or accepting aggressive or hostile feelings. Therefore, hostility may be expressed through indirect or passive means. Although these individuals may demonstrate good interpersonal skills, their ability to form rewarding, reciprocal, and mature relationships is likely to be impaired.3

Although the first three clinical scales have received most of the attention with regard to medical patients, the other clinical scales also provide valuable information. Individuals with an elevated score on Scale 4 (psychopathic deviate) tend to have difficulty delaying gratification, have trouble with authority, and may engage in antisocial behavior. Scale 5 (Masculinity-Femininity) is interpreted differently for men and women. Men with an elevated Scale 5 score often exhibit creativity, sensitivity, and passivity; whereas women exhibit assertiveness and self confidence.4 Individuals who score high on Scale 6 (paranoia) can exhibit frank psychotic functioning, have a suspicious predisposition, or feel abused and mistreated. An elevation on Scale 7 (psychasthenia) may suggest that a person is tense, anxious, and ruminative. A high score on Scale 8 (schizophrenia) can be attributed to several possible reasons, including feelings of alienation and bizarre sensory experiences (e.g., numbness and tingling). Often these individuals carry with them a sense of being damaged and may have difficulty exercising reasonable judgment. Individuals with elevated scores on Scale 9 (hypomania) tend to throw themselves into excessive, and often unproductive, activity as a way to distract themselves from distressing emotions. Further, they may not have a realistic sense of their limitations. Scale 0 (social introversion) appears to detect individuals who prefer to be alone.3

First published on: April 1, 2006