Further Examining the Construct Validity of the Minnesota Multiphasic Personality Inventory-2-Restructured Form (MMPI-2-RF) Personality Disorder Spectra Scales.

The Minnesota Multiphasic Personality Inventory-2-Restructured Form (MMPI-2-RF) Personality Disorder (PD) Spectra scales reflect a recent effort to dimensionally measure Diagnostic and Statistical Manual of Mental Disorders-5-based personality disorders. Initial studies generally support the sound psychometric properties of most scales, although the need to continue cross-validating and expanding the known empirical correlates of these scales remains. The goal of the current investigation was to replicate and extend previous research on MMPI-2-RF PD Spectra scale scores and further examine their construct validity. Using a sample of 765 undergraduate students (69.3% female; Mage = 19.95; 73.3% White), zero-order correlations between scores on MMPI-2-RF PD Spectra scales and measures of personality and psychopathology variables were calculated. Median convergent and discriminant correlations were compared using Fisher's r-to-z tests. Results indicated that hypothesized convergent associations were meaningfully stronger in magnitude than hypothesized discriminant ones, with exceptions to scales measuring Obsessive-Compulsive, Narcissistic, and Paranoid PDs. Findings generally supported the construct validity of MMPI-2-RF PD Spectra scale scores. Implications for clinical practice and research, methodological limitations, and suggestions for future research are discussed.

Utility of the MMPI-3 validity scales for detecting overreporting and underreporting and their effects on substantive scale validity: A simulation study.

The current study utilized an experimental design to investigate the utility of the Minnesota Multiphasic Personality Inventory (MMPI)-3 Validity Scales for detecting overreporting and underreporting and the impact of these response sets on substantive scale scores. College students completed a battery of criterion measures before assignment to a Standard Instructions (SIs) Group (n = 288), an Overreporting Group (n = 250), or an Underreporting Group (n = 215). t tests demonstrated that scores on MMPI-3 overreporting indicators and most substantive scales were higher among the Overreporting Group relative to the SI group with very large effect sizes, and scores on MMPI-3 underreporting indicators were higher and most substantive scales scores were lower among the Underreporting Group relative to the SI group, with moderate to large effects. Classification accuracy estimates documented the effectiveness of MMPI-3 Validity Scales in detecting overreporting and underreporting. Bivariate correlations between MMPI-3 substantive scale scores and criterion measures (which were completed under SIs for all three groups) were substantially attenuated for both simulation groups relative to the SI Group. Bivariate correlations were also attenuated for groups identified as overreporting or underreporting using MMPI-3 Validity Scale scores relative to individuals with valid MMPI-3 protocols, highlighting the need for and importance of appraising threats to protocol validity when assessing personality and psychopathology by self-report. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Associations Between MMPI-2-RF Internalizing RC Scales and Positive Characteristics.

Past studies indicate that the low scores on the MMPI and MMPI-2 Clinical and Content Scales can reflect positive characteristics. It is currently unclear, however, whether scales on the MMPI-2-Restructured Form (MMPI-2-RF) have that ability. Accordingly, we examined whether low scores on Restructured Clinical (RC) Scales assessing internalizing difficulties (i.e., RCd, RC2, and RC7) can reflect self-esteem, life satisfaction, positive and negative affect, and optimism. When considering the full range of scores, each of the internalizing RC Scales demonstrated the expected pattern of associations with these characteristics. Across difference and percentage bend analyses, however, only RC2 had significant associations-namely, with positive affect, self-esteem, and life satisfaction. This study corroborates that high scores on the internalizing RC scales have interpretations consistent with past literature, but also uniquely suggests that below average RC2 scores may reflect increased positive affect, self-esteem, optimism, and satisfaction with life.

Assessing the Clinical Utility of the MMPI-2-RF in Detecting Suicidal Ideation in a High Acuity, Partially-Hospitalized Veteran Sample.

The Minnesota Multiphasic Personality Inventory-2-Restructured Form (MMPI-2-RF; Ben-Porath & Tellegen, 2008/2011) has demonstrated utility in suicide risk assessment. Limited research with the MMPI-2-RF in higher acuity populations exists, particularly regarding the impact of possible underreporting on prediction of suicide risk. The current study serves to extend previous findings of the utility of clinically indicated MMPI-2-RF scales and proxy indices in 293 veterans (83.62% White, 85.32% male, and 74.40% with past-week suicide ideation) enrolled in a Veterans Affairs Medical Center partial psychiatric hospitalization program. Differences in self-report indicators and MMPI-2-RF scales and proxy indices relevant in assessing suicide ideation between veterans indicated as possibly underreporting and those who were not and the ability of the scales and proxy indices to predict current suicide ideation were examined. These indicators, scales, and proxy indices, with the exception of SUI, were significantly impacted by underreporting, and none of the examined scales or proxy indices (or their interaction) were consistently associated with self-reported suicide ideation after accounting for SUI. However, SUI was consistently associated with suicide ideation and was less influenced by under-reporting. In acutely ill psychiatric patients, SUI may be the most robust indicator of current suicide ideation.

Validity testing in veterans with epileptic seizures and psychogenic nonepileptic seizures.

OBJECTIVE: Identification of clinically meaningful subgroups among patients with psychogenic nonepileptic seizures (PNES) or epileptic seizures (ES) is of potential value for assessing prognosis and predicting therapeutic response. Invalid performance on validity tests has been associated with noncredible complaints and worse cognitive test scores, and may be one such classification criteria. We studied invalid performance in Veterans with PNES or ES, and the association of invalid performance with cognitive test scores and subjective complaints. METHODS: Patients were consecutive admissions to three veterans affairs (VA) epilepsy monitoring units. Evaluations included two validity tests: the Test of Memory Malingering (TOMM); and the Minnesota Multiphasic Personality Inventory-2-Restructured Form (MMPI-2-RF) over-reporting validity scales. We compared the frequency of invalid performance on the TOMM or MMPI-2-RF in patients diagnosed with PNES vs. ES. We evaluated the association of invalid performance with scores on the Repeatable Battery for Assessment of Neuropsychological Status (RBANS), and four subjective symptom measures including the Beck Depression Inventory-II, and Quality of Life in Epilepsy-31. RESULTS: Invalid TOMM performance was found in 25.3% of Veterans diagnosed with PNES and 10.8% of those with ES (p = .03). Invalid reporting on the MMPI-2-RF was found in 35.9% of the PNES group vs. 15.3% of the ES group (p = .01). Effects of valid vs. invalid reporting on external measures were similar for ES and PNES groups. Patients with invalid vs. valid TOMM performance had lower scores on the RBANS (p < .001). Patients with invalid performance had greater complaints on all subjective measures, with largest effect sizes for the MMPI-2-RF validity scales (p < .001). SIGNIFICANCE: In Veterans admitted for evaluation of poorly controlled seizures, invalid performance on validity tests was not uncommon. Cognitive test results and subjective reports from patients with invalid performance may not be credible. These observations have implications for the analysis of clinical trials, where primary and secondary outcomes often rely on self-report measures.

Personality profile of the primary blepharospasm (BSP): An investigation using the Minnesota Multiphasic Personality Inventory.

OBJECTIVE: To explore whether patients with blepharospasm (BSP) have abnormal personality traits by the Minnesota Multiphasic Personality Inventory (MMPI) questionnaire. METHOD: The personality profiles of patients with BSP and its relationship with clinical characteristics were assessed in this research. 46 patients with BSP and 33 age-and-gender matched healthy controls were assessed using the MMPI questionnaire. The scores of three validity scales and ten clinical scales were calculated and compared. Then the relationship between those scales and clinical characteristics of patients with BSP was analyzed in the BSP group. RESULTS: It was found that patients with BSP scored significantly higher than healthy controls on the D, Hy, Pt clinical scales. The peak values of profiles were Hy, D, Hs scale scores. However, there was no statistical relationship between the clinical scales of MMPI and the clinical characteristics of BSP after Bonferroni Correction. CONCLUSION: The findings indicated that MMPI could be a useful psychometric tool to characterize a specific pattern of the personality of BSP patients and BSP patients may have avoidant and somatization personality characteristics.

Generalizability of statistical prediction from psychological assessment data: An investigation with the MMPI-2-RF.

In the present study, the author employed tools and principles from the domain of machine learning to investigate four questions related to the generalizability of statistical prediction in psychological assessment. First, to what extent do predictive methods common to psychology research and machine learning actually tend to predict new data points in new settings? Second, of what practical value is parsimony in applied prediction? Third, what is the most effective way to select model predictors when attempting to maximize generalizability? Fourth, how well do the methods considered compare with one another with respect to prediction generalizability? To address these questions, the author developed various types of predictive models on the basis of Minnesota Multiphasic Personality Inventory (MMPI)-2-RF scales, using multiple prediction criteria, in a calibration inpatient sample, then externally validated those models by applying them to one or two clinical samples from other settings. Model generalizability was then evaluated based on prediction accuracy in the external validation samples. Noteworthy findings from the present study include (a) statistical models generally demonstrated observable performance shrinkage across settings regardless of modeling approach, though they nevertheless tended to retain non-negligible predictive power in new settings; (b) of the modeling approaches considered, regularized (penalized) regression methods appeared to produce the most consistently robust predictions across settings; (c) parsimony appeared more likely to reduce than to enhance model generalizability; and (d) multivariate models whose predictors were selected automatically tended to perform relatively well, often producing substantially more generalizable predictions than models whose predictors were selected based on theory. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Validating the usefulness of the NSI validity-10 with the MMPI-2-RF.

Purpose/Aim of the Study: The Neurobehavioral Symptom Inventory (NSI) is a 22-item self-report measure created to quantify the somatosensory, cognitive, and affective symptoms of Post-concussive Syndrome. Developers of the NSI used a subset of 10 items, the Validty-10, to measure symptom overreporting. We compared the Validity-10 versus the remaining NSI items (i.e., the Remaining-12) for how accurately they detect symptom exaggeration on the Minnesota Multiphasic Personality Inventory Second Edition - Restructured Form (MMPI-2-RF).Materials and Methods: We used a sample of 45 veterans evaluated in a Polytrauma/TBI Clinic of a Midwest VA Healthcare System who completed the NSI and MMPI-2-RF.Results: The Vaidity-10, Remaining-12, and Total Score all strongly correlated with mean of the MMPI-2-RF validity scales (r = .65, .67, and .70, respectively), illustrating equivalency among the various NSI scores. Groups were created based on significant T score elevation on any MMPI-2-RF validity scale (i.e. F-r > 119, or Fp-r, F-s, FBS, or RBS > 99). ROC analyses demonstrated that areas under the curve were equivalent for NSI Total Score (.84), Validity-10 (.81), and Remaining-12 (.81) in detecting overreporting.Conclusions: These findings do not support the notion that the Validity-10 has unique utility as an embedded symptom validity scale and highlights the likelihood that NSI Total Score can also serve this function.

Flexible and Conditional Administration of the Minnesota Multiphasic Personality Inventory-2-Restructured Form in Presurgical Psychological Evaluations of Spine Surgery Candidates.

The purpose of this study was to evaluate a flexible and conditional administration (FCA) for the MMPI-2-RF in archival samples of spine surgery and spinal cord simulator candidates presenting for presurgical psychological evaluations. The sample included 1,477 spine surgery candidates (709 male, 276 female) and 476 spinal cord stimulator candidates (178 male, 298 female). Using a simulation design, the results of this study indicated that an FCA of the MMPI-2-RF closely approximates the amount of information gained from a standard MMPI-2-RF administration. In addition, time savings were substantial in both samples, particularly the spine surgery sample, as item savings varied from 40% to 80%, depending on the number of substantive domains flexibly administered. Overall, the results of the study lend support for the feasibility of the FCA approach in presurgical evaluations of spine surgery candidates, in particular for those situations where the length of the test would otherwise preclude its use.

The Relationship of MMPI-2-RF Scales to Treatment Engagement and Alliance.

Clients' personality characteristics can be important correlates of treatment engagement and alliance. The Minnesota Multiphasic Personality Inventory-2-Restructured Form (MMPI-2-RF) is one of the most comprehensive and widely used personality measures in clinical settings and includes measures of symptom validity. A few prior studies using the MMPI-2 and MMPI-2-RF suggest that externalizing characteristics and the validity scales might be associated with treatment engagement, but no studies to date have examined MMPI correlates of treatment alliance. This study examined the relationship of MMPI-2-RF scales to treatment engagement and alliance in 134 individuals seeking outpatient treatment at a psychology department training clinic. It was predicted that validity scales and externalizing scales would be related to treatment engagement (premature termination, no-show rate) and to alliance. Contrary to expectations, MMPI-2-RF validity scales were not related to premature termination but high scores on F-r were related to higher no-show rates and high scores on Symptom Validity (FBS-r) were related to lower alliance. As predicted, higher scores on scales assessing externalizing psychopathology were related to premature termination and higher no-show rate. Exploratory analyses also suggested higher scores on somatic and interpersonal scales were related to lower alliance. Accuracy statistics using clinical cutoffs on MMPI scales are provided.

The MMPI factor scales and risk of death in men during 45 years of follow-up: The Western Electric study.

We examined associations between personality traits measured in 1958 and both all-cause and cause-specific mortality assessed 45 years later in 2003. Participants were 1,862 middle-aged men employed by the Western Electric Company. Outcomes were days to death from all causes, coronary heart disease, stroke, cancer, and causes other than circulatory diseases, cancer, accidents/homicide/suicides, or injuries (other causes). Measures in 1958 included age, education, health behaviors, biomedical risk factors, and nine content factors identified in the Minnesota Multiphasic Personality Inventory (MMPI). Four content factors-neuroticism, cynicism, extraversion, and intellectual interests-were related to the five-factor model domains of neuroticism, agreeableness, extraversion, and openness, respectively. The remaining five-psychoticism, masculinity versus femininity, religious orthodoxy, somatic complaints, and inadequacy-corresponded to the five-factor model's facets and styles (combinations of two domains) or were unrelated to the five-factor model. In age-adjusted and fully adjusted models, cynicism was associated with greater all-cause and cancer mortality. In fully adjusted models, inadequacy was associated with lower all-cause mortality and lower mortality from other causes. In age-adjusted models, religious orthodoxy was associated with lower cancer mortality. Further analyses revealed that the association between cynicism and all-cause mortality waned over time. Exploratory analyses of death from any disease of the circulatory system revealed no further associations. These findings reveal the importance of cynicism (disagreeableness) as a mortality risk factor, show that associations between cynicism and all-cause mortality are limited to certain periods of the lifespan, and highlight the need to study personality styles or types, such as inadequacy, that involve high neuroticism, low extraversion, and low conscientiousness. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Patterns of MMPI-2-Restructured Form (MMPI-2-RF) validity scale scores observed across Veteran Affairs settings.

The purpose of this investigation is to provide descriptive information on veteran response styles for a variety of VA referral types using the Minnesota Multiphasic Personality Inventory (MMPI)-2-Restructured Form (MMPI-2-RF), which has well-supported protocol validity scales. The sample included 17,640 veterans who were administered the MMPI-2-RF between when it was introduced to the VA system in 2013 until May 31, 2015 at any VA in the United States. This study examines frequencies of protocol invalidity based on the MMPI-2-RF's validity scales and provides comprehensive descriptive findings on validity scale scores within the VA. Three distinct trends can be seen. First, a majority of the sample did not elevate any of the validity scales beyond their recommended interpretive cut-scores, indicating that scores on the substantive scales would be deemed valid and interpretable in those cases. Second, elevation rates are higher for the overreporting scales in comparison to the underreporting and non-content-based invalid responding scales. Lastly, a majority of those with an elevation on one overreporting validity indicator also had an elevation on at least one other overreporting scale. Implications for practice and the utility of the MMPI-2-RF within the VA are discussed. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

A Comparison of the Descriptive Information from the MMPI-2 and MMPI-2-RF.

Do MMPI-2 or MMPI-2-RF profiles differ in how accurately they depict examinees? To explore this question, we examined differences in clinical descriptions of equivalent profiles from the two instruments. Fourteen valid MMPI-2 protocols from an archival private practice sample were scored as both the MMPI-2 and the MMPI-2-RF. The resulting 28 profiles were coded separately by four raters using the Midwestern Q-Sort. Examinee descriptions from the two instruments were compared in terms of their (a) similarity, operationalized by q-correlations between corresponding MMPI-2 and MMPI-2-RF ratings; (b) descriptive validity, operationalized by correlations with q-sorts provided by the examinees' therapists; and (c) incremental descriptive validity, operationalized by incremental prediction of the therapist q-sorts by the MMPI-2 and MMPI-2-RF, one over the other. Descriptions from corresponding MMPI-2 and MMPI-2-RF score reports were highly intercorrelated. Ratings from both were valid predictors of therapist descriptions, and neither clearly outperformed the other in terms of incremental validity.

Reliability and Validity of the Minnesota Multiphasic Personality Inventory - 2 - Restructured Form (MMPI-2-RF) in Spine Surgery and Spinal Cord Stimulator Samples.

It is not uncommon for patients to report diminished outcomes as a result of spine surgery or a spinal cord stimulator implant. Presurgical psychological evaluations are increasingly used to identify patients at increased risk for such outcomes and use of personality assessment instruments in these evaluations provides incremental information beyond a clinical interview and medical chart review. This investigation explores the psychometric properties of the Minnesota Multiphasic Personality Inventory-2-Restructured Form (MMPI-2-RF) in a sample of spine surgery patients (n = 810) and in a sample of spinal cord stimulator patients (n = 533). Results indicated that MMPI-2-RF substantive scale scores are reliable, with evidence of good convergent and discriminant validity in both samples. Incorporating the MMPI-2-RF as part of the presurgical evaluation of spine surgery and spinal cord stimulator patients can provide meaningful insight into patients' functioning and help guide pre- and postsurgical treatment in these settings.

The Utility of the MMPI-2-RF Validity Scales in Detecting Underreporting.

This study examined the validity of the Minnesota Multiphasic Personality Inventory-2-Restructured Form (MMPI-2-RF; Tellegen & Ben-Porath, 2011) Uncommon Virtues (L-r) and Adjustment Validity (K-r) scales in detecting underreporting. The study aimed to increment the previous literature in this field using a New Zealand population. We used a combined sample of 784 university students, with 173 participants completing the MMPI-2-RF with instruction to underreport in the context of applying for a job, and 611 completing the test under standard instructions. Results indicated that individuals who completed the MMPI-2-RF with underreporting instructions exhibited significantly lower scores on the majority of the MMPI-2-RF substantive scales, and significantly higher scores on the L-r and K-r validity scales. Additionally, L-r and K-r added incremental predictive utility over one another when differentiating the standard instruction and underreporting groups. Classification accuracy analyses provided additional evidence for the utility of the L-r and K-r scales by supporting their respective cut scores listed in the MMPI-2-RF manual (Ben-Porath & Tellegen, 2011). The findings of this study provide further evidence for the utility of the L-r and K-r scales in detecting underreporting extension to both a preemployment evaluation context and a novel population.

Psychological Assessment Instruments for Use in Liver and Kidney Transplant Evaluations: Scarcity of Evidence and Recommendations.

Psychopathology among liver and kidney transplant patients is prevalent. Although pre-surgical psychological evaluations are routinely conducted, understanding which specific psychological test to use is under-developed. The purpose of this review is to examine the psychometric properties of broadband and narrowband psychological measures in pre-surgical liver and kidney transplant evaluations. Overall, there is a paucity of research in this domain that hamper abilities to make clear recommendations on what to use alongside a clinical interview. This review highlights the need for additional research examining instruments that may predict patients' successful recovery from transplant surgery. Despite the scarcity of research, instruments that appear to be useful in this population include the Minnesota Multiphasic Personality Inventory-2 (MMPI-2), the Personality Assessment Inventory (PAI), the Stanford Integrated Psychosocial Assessment for Transplantation (SIPAT), and the Transplant Evaluation and Rating Scale (TERS).

Validation of MMPI-2-RF Personality Disorder Spectra scales in a psychiatric sample.

The diagnostic operationalization of personality disorders is at the crossroads. The Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM-5), includes 2 separate systems for the diagnosis of personality disorders (PDs)-1 that is purely categorical (Section II) and 1 that is primarily dimensional (Section III). The International Classification of Diseases (11th ed.) will use a dimensional approach for the diagnosis of PDs. The Minnesota Multiphasic Personality Inventory 2-Restructured Form (MMPI-2-RF) PD Spectra scales were developed as measures of both the traditional and the alternative and scientifically supported systems. The current study examined the criterion and construct validity of these scales in a sample of 343 psychiatric patients. Patients completed the MMPI-2-RF, a measure of traditional personality disorders, a measure of the DSM-5 alternative model of personality disorder traits, and a measure of the 5-factor model of personality. Overall, with the exception of the Narcissistic and the Obsessive-Compulsive PD Spectra scales, the criterion and construct validity findings were quite supportive of these scales. Implications of these findings are discussed. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Does MMPI assessed at medical school admission predict psychological problems in later years?

OBJECTIVE: Psychological distress among medical students is related to personality. The Minnesota Multiphasic Personality Inventory (MMPI) is a common instrument used to assess personality and psychological problems during the medical school admission process in Thailand. The purpose of this study was to examine how the MMPI can predict medical students' psychological problems including perceived stress, anxiety, depression, interpersonal difficulties as well as self-esteem in later years. RESULTS: Anxiety and depressive symptoms were predicted by the psychopathic deviation, psychasthenia, and schizophrenia scales of the MMPI, while perceived stress was predicted by schizophrenia scale of MMPI. Social introversion predicted interpersonal difficulties. No MMPI scale was found to predict self-esteem.

Identifying non-affective psychosis in first admission patients: MMPI-2, structured diagnostic interview, and consensus lifetime best estimate.

PURPOSE: We aimed to evaluate the Minnesota Multiphasic Personality Inventory-2 (MMPI-2) as a potential means of improving on the SCID's diagnostic efficacy. METHODS: 76 first-admission patients were assigned DSM-IV consensus diagnoses by two experienced psychiatrists using all available information, then dichotomized into non-affective psychosis and other mental illness groups. The patients were also given the SCID and the MMPI-2. The diagnostic performance of the MMPI-2 was compared to that of the SCID to assess both diagnostic accuracy and incremental validity. RESULTS: MMPI-2 scales 8 (Schizophrenia) and BIZ (Bizarre Mentations) correctly identified 58% and 56% respectively of non-affective psychotic patients. The Goldberg Index had an overall correct classification rate of 70%, but only identified 49% of the psychosis group. The SCID had a correct classification rate of 66% but correctly identified only 25% of the non-affective psychosis patients. Three MMPI-2 scales combined with the SCID resulted in an overall correct classification rate of 73%, and identification of 66% of the non-affective psychosis patients. CONCLUSION: The results suggest that the MMPI-2 may identify early psychosis at least as well as the SCID. Furthermore, using a combination of the MMPI-2 and the SCID shows incremental validity over using the SCID alone.

Examination of the Minnesota Multiphasic Personality Inventory-2-Restructured Form (MMPI-2-RF) validity and substantive scales in patients with electrical injury.

Objective: Electrical injury (EI) is a distinct subtype of traumatic injury that often results in a unique constellation of cognitive sequelae and unusual sensory experiences due to peripheral nervous system injury that are uncommon in general medical/neurological populations and have been unexplored with the Minnesota Multiphasic Personality Inventory-2-Restructured Form (MMPI-2-RF). Method: This study examined performance patterns on MMPI-2-RF validity and substantive scales among 62 EI patients who underwent neuropsychological evaluation, of which 46 demonstrated valid symptom reporting and neurocognitive test performance via multiple independent validity indicators and were retained for analysis. Results: Valid EI patients scored significantly higher than the MMPI-2-RF normative sample on several validity scales with the largest effect sizes on F-r (Infrequent Responses), Fs (Infrequent Somatic Responses), FBS-r (Symptom Validity), and RBS (Response Bias), and ≥33% obtaining elevated scores on these scales per standard interpretive criteria. Review of item content on these scales revealed several reflect disturbances in sensation, physical functioning, and/or cognition that are not infrequent in this population. Further, MMPI-2-RF clinical profiles did not reveal generalized distress or noncredible over-reporting. Rather, similar to the MMPI-2, valid EI patients had a specific pattern related to physical/sensory symptoms and reduced positive emotions with elevations on restructured clinical (RC) scale 1 (somatic complaints), somatic/cognitive specific problem scales, and low positive emotions (RC2). Conclusions: Elevations on some MMPI-2-RF validity scale may capture some degree of actual EI sequela that neuropsychologists need to consider to prevent erroneously concluding that a credible EI patient is over-reporting when s/he is reporting bona fide, EI-related symptoms.