Commentary on Delis and Wetter, Cogniform disorder and cogniform condition: Proposed diagnoses for excessive cognitive symptoms

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1 Archives of Clinical Neuropsychology 22 (2007) Abstract Commentary Commentary on Delis and Wetter, Cogniform disorder and cogniform condition: Proposed diagnoses for excessive cognitive symptoms Glenn J. Larrabee 2650 Bahia Vista St., #308, Sarasota, FL United States Accepted 27 July 2007 This commentary discusses the criteria proposed by Delis and Wetter [Delis, D. C., & Wetter, S. R. (2007). Cogniform disorder and cogniform condition: Proposed diagnoses for excessive cognitive symptoms. Archives of Clinical Neuropsychology, 22, ] for diagnosis of Cogniform Disorder and Cogniform Condition. These criteria are intended to establish a new category of somatoform disorder, that is specific to cognitive complaints and/or neuropsychological dysfunction that are either atypical or excessive for bona fide neurological, psychiatric or medical conditions, and that are not the product of malingering. The Cogniform criteria are considered in relation to the criteria for Malingered Neurocognitive Dysfunction (MND) proposed by Slick et al. [Slick, D. J., Sherman, E. M. S., & Iverson, G. L. (1999). Diagnostic criteria for malingered neurocognitive dysfunction: Proposed standards for clinical practice and research. The Clinical Neuropsychologist, 13, ], with discussion of issues relative to establishing intent for diagnoses of definite and probable MND. Chronic post-concussion syndrome is considered as a specific example of a Cogniform Disorder or Condition Published by Elsevier Ltd on behalf of National Academy of Neuropsychology. Delis and Wetter have critically reviewed the psychiatric and neuropsychological literature, and produced a clinically and rationally derived set of diagnostic criteria for establishment of two disorders, Cogniform Condition, and Cogniform Disorder, that can be subsumed under the general DSM-IV category of somatoform disorders. The authors establish the need for these new disorders by a review of existing diagnostic categories in DSM-IV that do not allow for characterization of excessive cognitive symptoms. Additionally, Delis and Wetter (2007) devote considerable discussion to the problems inherent in determining intentionality as another justification for development of the Cogniform diagnostic criteria. Cogniform Condition and Cogniform Disorder are defined by cognitive symptoms such as memory and concentration difficulties that are in excess of objective physical evidence. Specifically, the patient presents with a pattern of cognitive complaints or low scores on psychometric cognitive tests that are considered to be excessive because they cannot be fully explained by neurological or psychiatric disorders, by a general medical disorder or by other factors known to influence cognitive function. If these symptoms or performances occur in conditions known to affect cognitive function, the presentation of the patient is in excess of what would be predicted based on the typical manifestation of the disorder. Tel.: ; fax: address: GLarrabee@aol.com /$ see front matter 2007 Published by Elsevier Ltd on behalf of National Academy of Neuropsychology. doi: /j.acn

2 684 G.J. Larrabee / Archives of Clinical Neuropsychology 22 (2007) Delis and Wetter offer several features that constitute evidence for presence of Cogniform Disorder or Condition, that encompass various atypical presentations of cognitive symptoms and/or cognitive performance on standard clinical tests. These features are derived from criteria proposed by Slick, Sherman, and Iverson (1999), Sweet (1999), and Bush et al. (2005). Although Delis and Wetter use the descriptor excessive throughout their paper, the actual criteria they propose suggest that in addition to excessive symptom report, these criteria also incorporate atypical symptom report (e.g. claims of amnesia for remote autobiographical memory), and neurologically atypical patterns of test performance (e.g. impaired attention with normal memory). Delis and Wetter differentiate Cogniform Disorder from Cogniform Condition by the extent to which these diagnostic categories interfere with the patient s life. Cogniform Disorder refers to a disorder that reflects reported cognitive impairment that is widespread in impact, and consistently presented (the example given by the authors is a person who forfeits their driver s license due to their excessive or atypical cognitive symptoms and impaired test performance). By contrast, Cogniform Condition refers to a more circumscribed condition (not widespread in impact), and which includes inconsistencies, typically between abnormal test performance and normal activities of daily living. Continuing with the driving example, the patient performs in a very impaired manner on tests of visual motor and visual spatial functioning, yet continues to drive a motor vehicle. In this vein, Delis and Wetter distinguish the Cogniform Disorder patient as one who is acting out the sick role, whereas the patient with Cogniform Condition does not act out the sick role. Delis and Wetter provide discussion about the similarities and differences between Cogniform Disorder and Cogniform Condition, on the one hand, and Malingering on the other hand. All three conditions are similar in that they can involve evidence of inadequate effort and exaggeration on formal neuropsychological testing, and all three allow for presence of external incentive. The authors emphasize, however, that a diagnosis of Cogniform Disorder or Cogniform Condition should not (their emphasis) be made if there is reasonable evidence that the symptoms/performance abnormalities are produced in an intentional or volitional manner, in which case a diagnosis of Malingering may be warranted. As examples where Malingering is a more appropriate diagnosis, Delis and Wetter include below chance performance on two-alternative forced choice recognition memory testing; confession of intentionally poor performance; and selective reporting of two different sets of symptoms in two separate but simultaneous lawsuits for separate accidents. Importantly, as noted by the authors, a diagnosis of Cogniform Disorder or Cogniform Condition does not exclude the possibility of intentional production of the excessive symptoms; rather, these categories imply only that there is insufficient evidence at the time of the assessment to formulate a diagnosis of intentionality and therefore, Malingering. (page 599). Recognition of atypical or excessive cognitive symptoms as a form of somatoform disorder with provision of a set of formal diagnostic criteria for this clinical presentation is long overdue. Historically, others have noted the similarity between the psychological mechanisms related to somatoform disorder, and the mechanisms related to prolonged postconcussion disorder (Mittenberg, DiGiulio, Perrin, & Bass, 1992; Putnam & Millis, 1994). Mittenberg et al. s (1992) classic paper found that non-injured community volunteer persons naïve to information regarding mild head injury and asked to imagine their symptoms following a brief vignette describing the occurrence of a mild head injury, endorsed the same cluster of symptoms as were endorsed by patients who had actually experienced such an injury. Moreover, the mild head injury patients consistently underestimated the premorbid prevalence of these symptoms compared with the base rate in non-injured control subjects. Mittenberg et al. concluded that symptom expectations appeared to share as much variance with post-concussion syndrome as head injury itself, suggesting an etiological role for expectation. These authors explained the persistence of post-concussive disorder by selective attentional bias of the patient to benign emotional, physiological and memory symptoms, with misattribution of these symptoms to their mild head trauma, referencing mechanisms similar to those proposed by Barsky and Klerman (1983), and Mechanic (1972), to explain the physical symptom complaints characteristic of somatoform disorders. Putnam and Millis (1994) made similar points, observing that the physical (fatigue, dizzy spells), emotional (anger, impatience) and cognitive (memory, concentration) symptoms that comprise post-concussion syndrome occur frequently in the normal population (MMPI-2 normative data, cf. Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989; Lees-Haley & Brown, 1993). The ubiquitous nature of these symptoms, referred to by Lees-Haley, Williams, and Brown (1993) as the physiological and psychological noise associated with everyday living, provides the opportunity for misattribution of these everyday phenomena to perceived physical, cognitive and emotional impairments. In other words, the tendency of a person prone to overly focus on their symptoms and to misattribute these to their injury

3 G.J. Larrabee / Archives of Clinical Neuropsychology 22 (2007) interacts with the high frequency of occurrence of these symptoms in daily life, to reaffirm their diagnosis. Putnam and Millis drew from Mittenberg et al. s research, as well as the literature on psychological mechanisms offered to explain development of and maintenance of somatoform disorder (Mechanic, 1972; Watson & Pennebaker, 1989), to propose that persisting somatic complaints after mild traumatic brain injury (mild TBI) could best be conceptualized as a type of somatoform disorder. Delis and Wetter discuss these earlier seminal papers as part of the justification for their newly proposed diagnostic criteria. They also point out the danger of itatrogenesis (treatment caused disorder), consequent to misdiagnosis of brain dysfunction by health practitioners, in the absence of adequate medical or psychometric evidence for such a diagnosis. Delis and Wetter contend that this factor, and the presence of external or interpersonal incentives, interacts to support the beliefs of Cogniform patients in the authenticity of their symptoms. Recent work by Suhr and Gunstad (2002, 2004) on diagnosis threat, supports iatrogenesis as a mechanism in promoting persistent post-concussion syndrome. Specifically, in students with history of mild TBI, those who thought they were being examined due to their history of TBI performed more poorly on neuropsychological tests (though not in patterns suggestive of malingering) than did students with history of mild TBI who were tested under neutral instructions. Delis and Wetter have clearly gone beyond earlier investigators in proposing a diagnostic framework for considering cognitive symptoms and atypical cognitive performances as a variant of the somatoform disorders. Their considerable discussion of the problems inherent in establishing intent, and use of this as one of the major reasons to justify the need for the Cogniform diagnoses, does cause some concern. Slick et al. (1999) specifically avoided the establishment of intent in their diagnostic criteria for malingered neurocognitive dysfunction (MND). These MND criteria (also relied upon, in part, by Delis and Wetter in establishing their own Cogniform criteria) require the presence of a substantial external incentive, presence of evidence of multiple sources of invalid test performance (referred to as response bias; which can also include symptom exaggeration) in the absence of any neurological, psychiatric, or developmental condition that can fully explain the patient s symptomatology. In other words, if there is substantial external incentive, combined with significant evidence of invalid test performance/complaints, with no other viable neurological, psychiatric or developmental explanation, then what else can this be other than malingering? Delis and Wetter specifically acknowledge the value of worse-than-chance performance on a two-alternative forced choice test in establishing the intent characteristic of malingering. Pankratz (in Pankratz & Erickson, 1990) has characterized worse-than-chance performance as the smoking gun of intent (p. 385). Worse-than-chance performance is also recognized as the criterion for establishing definite negative response bias, which provides the psychometric evidence for the diagnosis of definite MND in Slick et al. (1999). Larrabee, Greiffenstein, Greve, and Bianchini (2007) reviewed data showing that persons identified by worse-than-chance performance did not differ in level of invalid test performance from non-injured persons attempting to simulate neuropsychological impairment in an imagined personal injury scenario, further supporting the association of worse-than-chance performance with intentional performance impairment. Evidence is beginning to appear that shows equivalence of test performance of persons identified as probable MND (i.e. by Slick et al., 1999 criteria showing multiple findings of invalid test performance, but not worse-than-chance) to that produced by persons identified as having definite MND. This is also reviewed in Larrabee et al. (2007). Of particular interest is the paper by Larrabee (2003), which utilized derived or embedded symptom validity indicators developed from standard clinical tests, to discriminate persons with definite MND from patients with moderate/severe TBI, and cross-validated these measures for discriminating persons with probable MND from psychiatric and neurological patients. When the definite and probable MNDs were compared to one another, they did not differ in level of performance on any of the five derived or embedded SVTs, nor did they differ on sensitive measures of word fluency, processing speed, verbal or visual memory; rather, the only difference was on the two-alternative forced choice task. This study and the other investigations reviewed by Larrabee et al. (2007) suggest that persons identified by the Slick criteria as having probable MND are exhibiting intentional response distortion similar to that manifested by persons demonstrating definite MND. The Cogniform Disorder and Cogniform Condition criteria have implications for categories of MND in the Slick et al. (1999) criteria, and for diagnoses in patients manifesting persistent post-concussion disorder. Regarding the Slick et al. criteria, patients with the diagnosis of possible MND may also meet criteria for the presence of Cogniform Disorder or Cogniform Condition. Per the above discussion and Larrabee (2003), it is unlikely that these new diagnostic criteria would be appropriate for persons meeting Slick et al. criteria for probable MND. Last, the criteria, as specified, would certainly not be appropriate for persons meeting the definite MND criteria.

4 686 G.J. Larrabee / Archives of Clinical Neuropsychology 22 (2007) The new diagnostic criteria for Cogniform Disorder and Cogniform Condition are potentially appropriate for patients manifesting persistent post-concussion syndrome. Binder, Rohling, and Larrabee (1997), employing meta-analytic techniques, estimated a 5% base rate of chronic, persistent cognitive impairment following a single, uncomplicated mild TBI. In an accompanying article, Binder (1997) reported that 7 8% of uncomplicated mild TBI had persistent symptomatic complaints. Assuming that there is overlap of the persistent impairment and persistent complaint groups, this suggests that 2 3% of subjects have persistent complaints in the absence of impairment, and this particular group would be appropriate to consider for one of the Cogniform diagnoses. The majority of mild TBI, however, make full and complete recoveries. The percentages of impairment reported above change when persons with mild TBI are encountered in forensic settings. Rutherford, Merrett, and McDonald (1978) reported a higher percentage of patients with chronic symptoms following minor head trauma, 14.5%, than later reported by Binder (1997), however, 8 of the 19 symptomatic patients were involved in law suits, and 6 had been suspected of malingering 6 weeks after their accident. In a subsequent review of his earlier work, Rutherford (1989) noted that the presence of litigation resulted in more than doubling the long-term symptom rate following mild TBI. Separate investigations by Mittenberg, Patton, Canyock, and Condit (2002), and Larrabee (2003) identify a malingering base rate of approximately 40% in litigants alleging mild TBI. These studies suggest that a significant percentage of mild TBI litigants would qualify for a diagnosis of probable or definite MND, with the remainder most likely representing Cogniform Disorder or Cogniform Condition, and some smaller percentage manifesting persistent neuropsychological dysfunction (note that more recent meta-analytic studies that incorporated data from sports concussion research, such as the investigation of Schretlen and Shapiro (2003), suggest that the 5% chronic persistent impairment determined by Binder et al. (1997), is an overestimate). In closing, Delis and Wetter have proposed new diagnostic categories of Cogniform Disorder and Cogniform Condition, that apply to those cases of non-malingering persons manifesting atypical or exaggerated cognitive symptoms, who heretofore did not fit in any meaningful diagnostic category. These criteria should see increasing clinical acceptance, not only for cases of persistent post-concussion syndrome, but for other medically unexplained conditions as well, including such conditions as silicone breast implant illness, fibromyalgia, chronic fatigue syndrome, multiple chemical sensitivities, and toxic mold and sick building syndrome (see Binder & Campbell, 2004). These criteria can also be used to inform research on the mechanisms underlying Cogniform symptom presentations, such as the work of Mittenberg et al. (1992) and Suhr and Gunstad (2002, 2004), and directed at those features that distinguish these disorders from the intentional response distortion characteristic of malingering. References Barsky, A. J., & Klerman, G. L. (1983). Overview: Hypochondriasis, bodily complaints, and somatic styles. American Journal of Psychiatry, 140, Binder, L. M. (1997). A review of mild head trauma. Part II. Clinical implications. Journal of Clinical and Experimental Neuropsychology, 19, Binder, L. M., & Campbell, K. A. (2004). Medically unexplained symptoms and neuropsychological assessment. Journal of Clinical and Experimental Neuropsychology, 26, Binder, L. M., Rohling, M. L., & Larrabee, G. J. (1997). A review of mild head trauma. Part I. Meta-analytic review of neuropsychological studies. Journal of Clinical and Experimental Neuropsychology, 19, Bush, S. S., Ruff, R. M., Troster, A. I., Barth, J. T., Koffler, S. P., Pliskin, N. H., et al. (2005). Symptom validity assessment: Practice issues and medical necessity. Archives of Clinical Neuropsychology, 20, Butcher, J. N., Dahlstrom, W. G., Graham, J. R., Tellegen, A., & Kaemmer, B. (1989). Minnesota multiphasic personality inventory. 2. Manual for administration and scoring. Minneapolis: University of Minnesota Press. Delis, D. C., & Wetter, S. R. (2007). Cogniform disorder and cogniform condition: Proposed diagnoses for excessive cognitive symptoms. Archives of Clinical Neuropsychology, 22, Larrabee, G. J. (2003). Detection of malingering using atypical performance patterns on standard neuropsychological tests. The Clinical Neuropsychologist, 17, Larrabee, G. J., Greiffenstein, M. F., Greve, K. W., & Bianchini, K. J. (2007). Refining diagnostic criteria for malingering. In G. J. Larrabee (Ed.), Assessment of malingered neuropsychological deficits (pp ). New York: Oxford University Press. Lees-Haley, P. R., & Brown, R. S. (1993). Neuropsychological complaint base rates of [170] personal injury claimants. Archives of Clinical Neuropsychology, 8, Lees-Haley, P. R., Williams, C. W., & Brown, R. S. (1993). The Barnum effect and personal injury litigation. American Journal of Forensic Psychology, 11, Mechanic, D. (1972). Social psychologic factors affecting the presentation of bodily complaints. New England Journal of Medicine, 286,

5 G.J. Larrabee / Archives of Clinical Neuropsychology 22 (2007) Mittenberg, W., DiGiulio, D. V., Perrin, S., & Bass, A. E. (1992). Symptoms following mild head injury: Expectation as etiology. Journal of Neurology, Neurosurgery, and Psychiatry, 55, Mittenberg, W., Patton, C., Canyock, E. M., & Condit, D. C. (2002). Base rates of malingering and symptom exaggeration. Journal of Clinical and Experimental Neuropsychology, 24, Pankratz, L., & Erickson, R. C. (1990). Two views of malingering. The Clinical Neuropsychologist, 4, Putnam, S. H., & Millis, S. R. (1994). Psychosocial factors in the development and maintenance of chronic somatic and functional symptoms following mild traumatic brain injury. Advances in Medical Psychotherapy, 7, Rutherford, W. H. (1989). Postconcussion symptoms: Relationship to acute neurological indices, individual differences, and circumstances of injury. In H. S. Levin, H. M. Eisenberg, & A. L. Benton (Eds.), Mild head injury (pp ). New York: Oxford University Press. Rutherford, W. H., Merrett, J. D., & McDonald, J. R. (1978). Symptoms at one year following concussion from minor head injuries. Injury, 10, Schretlen, D. J., & Shapiro, A. M. (2003). A quantitative review of the effects of traumatic brain injury on cognitive functioning. International Review of Psychiatry, 15, Slick, D. J., Sherman, E. M. S., & Iverson, G. L. (1999). Diagnostic criteria for malingered neurocognitive dysfunction: Proposed standards for clinical practice and research. The Clinical Neuropsychologist, 13, Suhr, J. A., & Gunstad, J. (2002). Diagnosis threat: The effect of negative expectations on cognitive performance in head injury. Journal of Clinical and Experimental Neuropsychology, 24, Suhr, J. A., & Gunstad, J. (2004). Further exploration of the effect of diagnosis threat on cognitive performance in individuals with mild head injury. Journal of the International Neuropsychological Society, 11, Sweet, J. J. (1999). Malingering: Differential diagnosis. In J. J. Sweet (Ed.), Forensic neuropsychology (pp ). Lisse, The Netherlands: Swets and Zeitlinger. Watson, D., & Pennebaker, J. W. (1989). Health complaints, stress, and distress: Exploring the central role of negative affectivity. Psychological Review, 96,

Exaggerated MMPI-2 symptom report in personal injury litigants with malingered neurocognitive deficit

Archives of Clinical Neuropsychology 18 (2003) 673 686 Exaggerated MMPI-2 symptom report in personal injury litigants with malingered neurocognitive deficit Glenn J. Larrabee Suite 202, 630 South Orange