The Symptom Checklist-Revised (SCL-90-R) is able to discriminate between simulation and fibromyalgia

This study assessed the ability of the Symptom Checklist-Revised (SCL-90-R) to discriminate between two groups of fibromyalgia patients (those who were about to begin a treatment including the explicit aim of returning to work and those who were initiating a legal procedure to obtain permanent disability compensation) and two groups of healthy volunteers (medical students and psychology graduates), who were asked to produce a symptomatic resemblance to a chronic pain disorder. Logistic regression analyses were applied to the SCL-90-R subscales and individual probabilistic indices of simulation were calculated. Results showed that the SCL-90-R was able to discriminate between healthy subjects and both groups of patients with a high sensitivity and specificity. The individual indices of simulation, which might be more useful in clinical practice than the comparison of the SCL-90-R profiles, also showed an appropriate level of accuracy.

Psychometric Perspectives on Detection of Malingering of Pain

Self-report plays a primary but not exclusive role in pain assessment. As is true of all self-reported experiences, under certain circumstances, the report of chronic pain can be distorted and misrepresented. There are unique challenges associated with the detection and assessment of malingering or self-report distortion in the evaluation of chronic pain. The current paper provides a rationale for the use of the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) in the comprehensive assessment of chronic pain with an emphasis on the advantage the MMPI-2 provides in the detection of response bias or malingering. A critical review of available MMPI-2 validity scales is presented, and recommendations for use of these scales in the evaluation of patients with chronic pain are made.

Depression Determines Illness Conviction and Pain Impact: A Structural Equation Modeling Analysis

OBJECTIVE

The present study sought to derive an algorithm using factor analysis and structural equation modeling (SEM) to describe headache and orofacial pain patients using measures of behavioral and psychological functioning. This investigation further examined whether the underlying factor structure differed in 3 presumed distinct diagnostic categories: myofascial, neuropathic, and neurovascular pain.

DESIGN

The Minnesota Multiphasic Personality Inventory-2 (MMPI-2), Multidimensional Pain Inventory (MPI), Beck Depression Inventory-II (BDI-II), and visual analog scale for functional limitation (VAS-FL) were administered to the subjects. A split group design was used. Exploratory factor analysis (EFA) was used to describe distinct factor domains in the first group. Confirmatory factor analysis (CFA) using SEM tested this structure in the second group and described causal relationships between the revealed (latent) factors. Analysis of variance (ANOVA) was used to test for differences in demographic variables and diagnostic group factor structure.

SETTING

The Pain Center is a comprehensive, multidisciplinary pain medicine program at Cedars-Sinai Medical Center, Los Angeles, California.

SUBJECTS

Three hundred and ninety (N = 390) subjects were assigned to 1 of 3 diagnostic categories: myofascial pain syndrome, neuropathic pain, or neurovascular pain.

RESULTS

EFA revealed a 3-factor solution. The factors were labeled Depression, Illness Conviction, and Pain Impact, reflecting the content of their respective variables with highest loadings. CFA using SEM validated the 3-factor solution, and further revealed that Depression was a critical causal factor determining Illness Conviction and Pain Impact. No causal relationship was observed between Illness Conviction and Pain Impact. ANOVA found no differences in demographics. No difference in factor structure emerged for the 3 diagnostic categories.

CONCLUSIONS

Analysis derived a 3-factor solution. The factors were Pain Impact, Illness Conviction, and Depression. SEM revealed the critical causal pathway showing that Depression determined Illness Conviction and Pain Impact. We conclude that the main target for pain treatment is depression. No differences in factor structure were found for the 3 diagnostic categories of myofascial, neuropathic, or neurovascular pain. This suggests that psychological processes are similar in chronic headache and orofacial pain patients despite their presumed distinct underlying pathophysiological mechanisms. SME is a powerful methodology to construct causal models that has been underutilized in the pain literature.

The Minnesota Multiphasic Personality Inventory and chronic pain: a conceptual analysis of a long-standing but complicated relationship

The Minnesota Multiphasic Personality Disorder (MMPI) and its successor, the MMPI-2, have a long-standing tradition in the assessment of patients with chronic pain. With the introduction of more narrowly defined and factor-analyzed pain inventories, however, the utility of the MMPI-2 for pain assessment has been brought into question. In this review, the relevant literature is carefully scrutinized from a conceptual and historical perspective. It is concluded that many of the (recent) criticisms are largely ungrounded. Rather than the test itself being at fault or of little utility in the field of pain assessment, it has simply been applied inappropriately (i.e., for determination of pain etiology or underlying personality structure "explaining" the chronic pain). In conclusion, it is suggested that the application of the MMPI-2 in the assessment of patients with chronic pain should correspond more closely to the original aims and psychometric properties of the tool--that is, for screening and the generation of hypotheses regarding comorbid psychopathology and personality features having the potential to complicate the treatment process. Guidelines for clinical interpretation of MMPI-2 profiles with regard to chronic pain are provided.