Assessing Neuro-Cognitive Complaints after Brain Injury: Distinguishing Fact from Fiction in Civil and Criminal Litigation

TASA ID: 2434

Plaintiffs and other petitioners often sue for damages due to reported cognitive or emotional impairment.  These cognitive impairments are often said to be the result of traumatic brain injury suffered in accidents, toxic exposures or medical procedures. Emotional impairments take the form of alleged depression or "traumatic" anxiety following such events, or those involving employment, business or similar affairs. Such impairments can often be subtle, not easily understood by nonprofessionals, but still claimed to have changed a person's life.

In such cases, clinical psychologists and clinical neuropsychologists are retained as experts to provide plaintiff or defense attorneys with an opinion on the validity, or truthfulness of the alleged injury.   In other words, is Mr. Smith really a victim who deserves compensation, a person whose condition is due to pre-injury factors, or a "malingerer" who is pulling a fast one? 

This article presents a brief overview of malingering assessment and symptom validity testing so that defense and plaintiff attorneys are better informed on how psychological experts can help them in their litigation. It also outlines the exact roles that experts can provide on these important matters. 

Malingering, or the exaggeration and/or fabrication of deficits in the pursuit of external gain, is a typical response by persons with compensable claims following injury or malpractice.  Clinical studies conducted in the past fifteen years estimate that the prevalence (or base rate) of malingering varies greatly; studies document rates from less than 10% to 50% for certain civil and criminal cases. In civil cases, the evidence includes documented instances of brain injury plaintiffs reporting impairment levels that do not fit with the known site of the injury. In criminal cases, the evidence includes defendants who exaggerate psychopathology during pre-trail assessment (i.e., "I was hearing voices at the time I committed the act"). These figures do not mean that half of every defense firm's case load includes malingering plaintiffs. It does mean that attorneys should perform "due diligence" and recognize the reality of malingering in civil and criminal cases. 

Malingering is defined in the Diagnostic and Statistical Manual of the American Psychiatric Association (1994 Washington, DC: American Psychiatric Press) as the intentional production of false or grossly exaggerated physical or psychological symptoms motivated by external gain. Yet as any savvy attorney will tell an ivory tower psychologist, scientific theory and courtroom evidence are often not the same. That is, making the determination that a person intentionally produces symptoms is often difficult to prove.  Plaintiff attorneys can argue that the burden of proof resides with the defense. That is, the psychologist must demonstrate with medical probability that the patient's neuro-cognitive symptoms are not due to other factors.   

A common and provable case occurs when a person denies a history of alcohol abuse, claims memory impairment due to accident, performs poorly on tests of cognitive functioning, and also has a documented medical or criminal history of alcohol abuse. In this instance, the psychologist's expert opinion is that the plaintiff is spinning two yarns; he is denying his criminal past and claiming current impairment. Unfortunately, few cases are that simple for psychologists to offer an opinion. 

When called upon to offer an opinion, clinical psychologists strongly suspect malingering when any of the following are documented in the records or evident on examination:

• Symptom exaggeration - pre-existing mild symptoms are inflated in their severity during examination
• Fabrication - Creation of false deficits where none exist, or the creation of deficits that are not associated with known pathology of brain dysfunction.

Expert psychological opinion on malingering also includes an understanding that there is no "typical" presentation of a malingerer.  That is, plaintiffs can exaggerate problems on assessment, by area of deficit (motor, cognitive, emotions), or by misreporting the evidence. 

In assessment, psychologists find evidence of the behavior that we call "response bias." That is, a less than below chance (< 50%) performance on forced choice measures (i.e., Yes or No) of cognitive functions, such as verbal or visual memory.  In other words, if a person just guessed at the answer (Yes or No), he/she should get at least 50 percent correct.   Any score far below chance suggests poor effort on the part of the plaintiff. 

Clinicians also assess bias when a person's performance is at odds with known pathology of brain dysfunction.  For example, a person may exaggerate motor deficits such as strength, stamina or speed in relation to orthopedic injuries. 

Finally, suspected malingerers also engage in misrepresenting psychological/emotional dysfunction in the area of mood (depression) and thinking (hallucinations).   They can appear emotionally distraught on the witness stand, or report depression on simple self- report questionnaires.  To assess those reported symptoms, psychologists use more precise and sophisticated objective tests such as the Minnesota Multiphasic Personality Inventory.  When assessing Spanish-speaking individuals of Mexican origin in such cases, the expert psychologist must use the official Spanish version of the MMPI, offered by the test's publishers and endorsed by the American Psychological Association, in order to provide reliable conclusions on the emotional functioning of that population.

While this information educates attorneys on the science of malingering assessment, there remains the question of how reliable the doctor's evidence or subsequent testimony is.  In other words, what is the evidentiary value of an expert's ability to differentiate a person with and without a specific disorder, such as PTSD or Cognitive Dysfunction following mild traumatic brain injury?  In addition, what is the probability or likelihood that a person's claims of neuro-cognitive dysfunction are not true, and may suggest malingering?

In malingering assessment, psychologists employ test instruments that have high rates on the statistical properties known as "sensitivity" and "specificity."  Sensitivity refers to the percentage of "true" malingerers predicted by a test.  That is, the likelihood of positive test scores in a person who is actually faking.  If a person with mild traumatic brain injury can immediately recall only three digits in succession from the Digit Span subtest, how likely does that suggest malingering?  

Regarding the issue of sensitivity, psychologists have accumulated considerable scientific evidence to indicate that persons with a variety of conditions (clinical depression, mild traumatic brain injury, bona fide malingerers, and "normal" controls) perform differently on symptom validity tests.  Hence, a plaintiff's performance can be compared to these groups, and the psychologist can begin to assess for the presence of malingering or inadequate effort.

Among the arsenal of tests that psychologists use in this expert role, "symptom validity tests" have become routine elements in a forensic assessment. Two types of symptom validity tests are used - specially designed tests of effort on discrete neuro-cognitive dysfunctions (simple counting ability or fine motor speed), or routine neuropsychological tests that have been adapted for the purposes of measuring the "truthfulness' of the person's test performance.   Symptom validity tests do not only use items that record simple Yes or No responses, but also measure continuous behaviors such as performance time, number of completions, recognition memory, etc. 

In contrast to a test's ability to "find a faker," specificity refers to the percentage of false malingerers, or actual patients, who perform on a test.  Or, how likely will a person who is not a malingerer still perform poorly on a test?  A person can perform poorly on a verbal list learning test, but it does not mean s/he is faking.  Such a person may have a learning disability, attention deficit disorder, or just be fatigued at the time of assessment.  

With this data in hand, psychologists may or may not be able to make a diagnosis of malingering. Yet, in our role as an expert on symptom validity, we can offer an admissible opinion on the matter by concluding that the person's history and performance indicate that a psychiatric diagnosis is "deferred."  This means that there is not sufficient or reliable evidence to substantiate the claim of neuro-cognitive dysfunction or emotional trauma.  Such evidence makes for a compelling argument in court room testimony. 

Finally, in our expert role on the validity of a plaintiff's reported complaints, we provide attorneys with the following services:

• Undeclared expert - A psychologist can serve as an expert who is not declared in proceeding, and hence be shielded from deposition, court room cross examination, etc. In this case, the psychologist or neuropsychologist offers expert opinion "behind the scenes" by providing an attorney with opinion on a plaintiff's medical records, or prior assessment.
• Formal assessment - A complete psychological and neuropsychological assessment, along the lines outlined above, can be performed on the plaintiff, claimant, or accused. As part of such assessments, psychologists routinely first inform the person that tests of effort and ability will be administered during the assessment. This serves the dual purpose of potentially offering added weight to findings of poor effort should they occur and blunting the plaintiff attorneys' argument that their client was tricked.

Plaintiff attorneys can counter defense claims of malingering when the evaluating psychologist makes the diagnosis based on too little data. Plaintiff attorneys should also inform their clients to truly "give their best effort." Just because the injured parties perform with great skill on certain cognitive measures, does not mean that their injury claims are invalid, or that the psychologist will not find evidence for impairment.

In conclusion, psychologists who conduct forensic assessments along the lines outlined in this article are best positioned to be effective experts in the assessment of plaintiffs' claims to neuro-cognitive or emotional impairments.

This article discusses issues of general interest and does not give any specific legal, medical, or business advice pertaining to any specific circumstances.  Before acting upon any of its information, you should obtain appropriate advice from a lawyer or other qualified professional.

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