Forensic Neuropsychology in Personal Injury Cases II Russell M. Bauer, Ph.D. July 17, 2008

Summary from Last Week Persistent deficits after mTBI are rare Even when present, severity of deficits is small (<.5 SD) NP impairment is often the only “objective” indicator of abnormality What to make of this? IMPORTANT REMINDER: SOME PATIENTS DO SUFFER RESIDUAL DEFICITS!!

“Noninjury” Contributors to Neuropsychological Impairment in MHI Adversarial patient-examiner relationship Expectation/attributional processes Diagnosis threat, role stereotypes Exaggeration or poor effort Impairment as communication Frank malingering for gain; financial incentives Factitious disorders Fatigue, pain, other physical factors Psychiatric/behavioral disturbance (e.g., psychosis, anxiety, depression) Cogniform disorder/cogniform condition Pre-existing factors affecting neuropsychological performance (e.g., learning disability, limited education) Occupational/life experience factors

Assessment of Malingering and Poor Effort Issues/problems with definition Intentional (intention) Fabrication or exaggeration (action) For purposes of gain (motive) Explanatory models (Rogers, 1997) Pathological (mental disorder) Criminological (fake) Adaptational (meeting adversarial demands) Cognitive vs. Somatic Malingering

Diagnosis Threat (Suhr & Gunstad, 2002) 37 MHI (17 in “diagnosis threat” condition) Diagnosis threat: told selected because of a MHI history; “a growing number of studies show that many individuals with head injury show cognitive deficits in neuropsychological tests”

Suhr & Gunstad, 2002

* Suhr & Gunstad, 2002

Cogniform Disorder/Cogniform Condition Patients with excessive cognitive complaints Difficulties with existing diagnostic options Symptom specificity Intentionality Presence of external incentive

COGNIFORM PRESENTATION

Pain and NP Performance Pain itself associated with mild NP performance decrements Pain medications Opioids: attention/concentration (on dose escalations) Neurobiological systems ACC, NA, extended amygdala Pain ALONE would not explain a -2SD discrepancy in severity Block & Cianfrini Neurorehabilitation, 2013; Moriarty, et al Prog Neurobiol, 2011.

Depression and NP Moderate effect sizes in executive function, memory and attention (-.34 to -.65) After treatment/remission, Executive/attention: -.52 to -.61 in patients with depression relative to controls (sig) Memory: -.22 to -.54 (nonsig) Suggests that “poor” cognition is a central, core feature Rock, et al., Psychological Medicine, 2013

Lim et al, Int Psychogeriatr, 2013 Meta-analysis of a total of 22 trials involving 955 MDD patients and 7,664 healthy participants. MDD < healthy: Digit Span, CPT (attention) TMT-A, Digit Symbol (processing speed) Stroop, WCST, Verbal Fluency (exec) Immed verbal memory (memory)MDD Other tests did not differentiate

Larrabee & Rohling, 2013

Effort, Motivation, & Response Styles Frederick et al., 2000

Malingering Algorithms: Slick (1999) Considers evidence from NP and self report 4 criteria Presence of incentive Evidence from NP Evidence from self-report Not better accounted for by….

Slick et al. (1999; cont’d) NP criteria Definite (below chance) or probable (low) response bias on FC measures Discrepancies/inconsistencies between NP data and patterns of brain functioning NP data and observed behavior NP data and reliable collateral reports NP data and past history

Slick et al. (1999; cont’d) Self-report criteria Self-report discrepant with history Self-report discrepant with known patterns of brain functioniong Self-report discrepant with behavioral observations Self-report discrepant with collateral information Evidence of exaggerated or fabricated psychological dysfunction

Slick et al, 1999 (cont’d) DEFINITE MND Presence of financial incentive Definite negative response bias Behaviors that meet criteria for negative response bias that are not fully accounted for by psychiatric, neurological, or developmental factors PROBABLE MND Presence of financial incentive Two or more types of evidence from NP, excluding definite response bias, or one piece of evidence from NP and one from self-report

Malingering Research Literature Case study Simulation studies Interpretive issues Appropriate designs Differential prevalence design contrasting high and low baserate groups (e.g., groups with and without financial incentives) Valuable mostly for determining average performances Known-groups design Selecting groups on the basis of malingering criteria (e.g., Slick, et al) Examining differences between the groups

Selecting Specialized Cognitive Effort Tests Ease of use Credibility of rationale Operating Characteristics Incremental validity TBI vs. PPCS Coaching issues There is not likely to be a “best” test in all circumstances

Commonly Used Specialized Tests Portland Digit Recognition Digit Memory Test Computerized Assessment of Response Bias (CARB) Word Memory Test (WMT) Victoria Symptom Validity Test Test of Memory Malingering Validity Indicator Profile Rey 15-Item Test Dot Counting Test

Detecting Anomalous Results with Embedded Measures and Performance Patterns Measures within standard NP tests that signify noncredible or ‘suspect’ performance Identification of such measures can be “rational” or “empirical” May be less subject to coaching than separate measures

Pattern Analysis Pattern Analysis With HRNB, DFA outperforms clinicians (80-90% v. 50-60%) Most DFA’s multivariate , consisting of attention and memory measures Generally, malingers score better on hard measures DFA’s exist for WMS-R, WMS-III, WAIS-R, WAIS-III and other tests Before using, investigate whether the DFA was validated/cross validated with known groups or simulators Iverson & Binder, 2000; Larrabee, 2005

Common “suspect” neuropsychological signs on NP testing Recognition << recall (hits, discriminability) Extremely poor DS in the context of normal auditory comprehension (RDS) Motor slowing (e.g., reduced tapping) relative to overt motor disability Excessive failures-to-maintain-set on WCST Discrepancies between test level and level during informal interaction Other “impossible” signs

Embedded Measures – Motor, Sensory, and Perceptual-Motor Perceptual-motor pseudoabnormality should not be overlooked b/c of emphasis on “higher” cognitive disabilities Approaches Neurologic exam Sensorimotor impairments on NP exam Findings RCFT copy 50% sensitive with lots of FP Malingering groups favor memory over visuoconstructive impairment (e.g. memory trials of RCFT discriminate better) Generally large grip strength effect size in K-G designs Reduced FT speed in the context of MHI

Embedded Cognitive Measures WMS-R/WMS-III Malingerers: Attention/Concentration < General Memory Opposite pattern is more typical of head injury Rarely-missed index on LM delayed recognition trials WAIS-R/WAIS-III: Digit Span Malingerers: Low digit span performance (ACSS < 5) Reliable Digit Span (sum of longest correct span for both trials < 8) Vocabulary – Digit Span (low digit span while vocabulary is high) CVLT Malingerers: Low recognition (hits & forced-choice) Cutoff scores for recall trials produce variable false-positive rates Variable results with most widely used cutoffs (Millis et al): Total < 35, LDCR <7, delayed recognition <11, discriminability < 81; sensitivity in question, not specificity

Malingering Patterns in NΨ Tests Pattern Analysis Word Memory Test Malingerers: Inconsistent responding, poor initial recognition Pattern should reflect severity of impairments Category Test Malingerers: Poor performance on first 2 subtests Wisconsin Card Sorting Task Malingerers: Poor ratios of categories completed compared to both perseverative errors and failure to maintain set Iverson & Binder, 2000; Larrabee, 2005

Why being a knowledgeable neuropsychologist is important You know likely patterns of impairment You know psychometric relationships among tests You know course of recovery You know about contributory factors (e.g., LD, depression, etc.) You can compare what you see to what you expect

Some Take Home Messages Use multiple measures (forced choice, embedded, etc.) Clarify your goals: sensitivity, specificity, etc. Be aware of correlations among malingering measures Look for emerging research on sensitivity/specificity of multiple indicators

Symptom Exaggeration Self-Report of Symptoms MMPI-2 May be exaggerated due to other variables (depression, pain, stress) e.g., Post-Concussive Syndrome persisting for more than 3 months MMPI-2 Malingerers tend to show elevations in clinical scales 1, 2, 3, 7, and 8, the Fake Bad Scale (FBS), VRIN, TRIN, the Infrequency-Psychopathology Scale [F(p)]. The F Scale and F – K does not appear to be as sensitive, and therefore “valid” profiles may be obtained. Caution should be given to interpreting the clinical scales and F Scale derivatives, as these can be easily influenced by psychiatric comorbidities. Iverson & Binder, 2000; Larrabee, 2005

Detecting Somatic Malingering Symptom report, as well as cognitive performance, can be controlled by the litigant Use of MMPI-2 F-scale, F(p) VRIN, TRIN Subtle-Obvious F-K index Revised Dissimulation Scales These scales may not be sufficiently sensitive to TBI-related claims, despite neuro-psychological differences

MMPI Measures FBS: 43 items – honest with bad injury; Originally the “Fake Bad Scale” and now the “Symptom Validity Scale” (FBS) Response Bias Scale (RBS): 28 items that predicted failure on CARB and WMT Henry-Heilbronner Index (HHI): 15 items sensitive to neurocognitive complaints in the months following head trauma

FBS Model of goal-directed behavior: Want to appear honest Want to appear psychologically normal except for the influence of injury Avoid admitting longstanding problems Minimize pre-existing complaints Minimizing pre-injury antisocial or illegal behavior Presenting plausible injury severity

Lees-Haley FBS (cont’d) 18 “True” , 25 “False” Does not correlate very strongly with F-scale derivatives Most scale items overlap with “neurotic” side of MMPI Cut-off mid 20’s, with varying false positive rates; increasing security with scores > 25-27

FBS Operating Characteristics Most frequently failed indicator of MND (Larrabee) FBS > 27 has Sn=.46 , Sp=.96, better than F or Fb (Greve et al) Sensitive to symptom exaggeration in personal injury, not just litigation Cutoffs determine TP, FP rate

Critical Studies Butcher et al (2003) Bury & Bagby (2002) Unacceptably high FP of FBS (24% of males, 37.9% of females exceeded cutoffs) Psychiatric, corrections, medical, pain, VA, personal injury litigants No measures of symptom validity external to the MMPI No report of who was litigating Can’t compute specificity or sensitivity without this information Bury & Bagby (2002) PTSD vs. students (standard and exaggeration instructions) F family produced best overall classification rates Entire PTSD sample were being evaluated for workplace disability Mean PTSD FBS was 26.31 No independent measures of malingering or exaggeration

RBS Sensitivity low (.34), specificity high (.96-.98) Specifically designed to predict SVT failure Outperforms F-family and FBS in doing this Seems to measure more “cognitive” than “somatic” factors

HHI Neurocognitive complaints in the immediate postinjury period. 9 items overlap with FBS, 4 with original “Pseudoneurologic Scale; PNS) Sensitivity 80%, Specificity 89% with a cutoff of > 8

Classification Accuracy of FBS, RBS, and HHI Participants were referred to a private practice for neuropsychological testing between 1999 and 2005. Patients were evaluated regarding a head injury in the context of litigation. Institutional Review Board approval was obtained and the study was in compliance with the ethical treatment of human participants. Archival data were extracted and de-identified. Participants were included if their files contained data for all 567 MMPI-2 items and at least three effort indicators. Using a criterion-groups design, participants were identified who appeared to exaggerate neurocognitive dysfunction. Criteria for inclusion and exclusion within noncredible and credible groups are described subsequently, including the use of performance measures of response bias for group assignment. Probable Negative Response Bias Group In total, 37 participants (age: M ¼ 44.5, SD ¼ 11.9; education: M ¼ 12.1, SD ¼ 1.8; Full-Scale Intelligence Quotient [FSIQ]: M ¼ 88.2, SD ¼ 9.0; 19 men and 30 women; 97.3% Caucasian and 2.7% African American) met the Slick and colleagues (1999) criteria for Probable Negative Response Bias (PNRB; Criterion B2). Used Rey-15, FTT total score, TOMM, WMT, and BCT (Booklet Category Test) Bolter infrequently missed items Although information regarding the severity of head injury was often not available, 25 participants reported post-traumatic amnesia congruent with mild head injury (,1 h). The Glasgow ratings for eight participants were mild (at least 13 points) and one was moderate (9–12 points). The reported length of time the participants were unconscious due to their head injury indicates 17 to be in the mild range (length of unconsciousness ≤30) and 5 to be in the moderate-to-severe range (length of unconsciousness .30 min). Nineteen participants reported their head injuries to be due to motor vehicle accidents (51.4%), eight reported injuries caused by a fall (21.6%), nine reported injuries due to work related accidents (24.3%), and one reported injury due to an assault (2.7%). Sixteen participants were evaluated within 6 months to a year post-injury (43.2%), 12 were within 1- to 3-year post-injury (32.4%), five were within 3- to 5-year post-injury (13.5%), one was within 5- to 7-year post-injury (2.7%), two were within 7- to 10-year post-injury (5.4%), and one was tested more than 10-year post-injury (2.7%). In regards to psychiatric comorbidity, two participants were diagnosed with depression and three were diagnosed with an adjustment disorder. Presumed Valid Group The presumed valid (PV) group consists of 42 participants (age: M ¼ 43.3, SD ¼ 11.5; education: M ¼ 12.2, SD ¼ 2.1; FSIQ: M ¼ 90.9, SD ¼ 16.0; 25 men and 17 women; 95.2% Caucasian, 2.4% African American, and 2.4% Native American). All were involved in litigation; however, none of the participants had a failure on any effort measure. Although information regarding the severity of head injury was often not available, 22 participants reported post-traumatic amnesia congruent with mild head injury (,1 h). The Glasgow ratings for 12 participants were mild (at least 13 points) and one was moderate (9–12 points). The reported length of time the participants were unconscious due to their head injury indicates 26 to be in the mild range (length of unconsciousness ≤30 min). Twenty-six participants reported their head injuries to be due to motor vehicle accidents (61.9%), six reported injuries caused by a fall (14.3%), four participants reported injuries due to work-related accidents (9.5%), four reported their injury as other (9.5%), one reported injury due to an assault (2.4%), and one reported injury due to sports and recreation (2.4%). Nineteen participants received evaluations within 6 months to a year post-injury (45.2%), 18 were within 1- to 3-year post-injury (42.9%), three were within 3- to 5-year post-injury (7.1%), and two were within 7- to 10-year post-injury (4.8%). In regards to psychiatric comorbidity, one participant was diagnosed with a posttraumatic stress disorder and three with an adjustment disorder. Dionysus et al., Arch Clin Neuropsychol, 2011