(424) 209-2992
2080 Century Park East, Suite 507 Los Angeles, CA 90067
Get in Touch

Before the Scores Mean Anything

Why neuropsychologists assess effort and symptom validity in every evaluation, and why a single failed validity test is not a verdict.

A neuropsychological evaluation produces a lot of numbers. Memory scores, processing speed, attention, problem-solving – each one compared against people of similar age and, often, similar educational background. Those numbers can shape a diagnosis, a treatment plan, a disability determination, or a jury’s understanding of what an injury cost someone.

But before any of those scores mean anything, a more basic question has to be answered: do the results actually reflect how this person’s brain works?

That question is what validity assessment is for, and it is one of the least understood parts of the field.

The first step in interpretation

The National Academy of Neuropsychology’s position paper on the subject puts it plainly. A primary step in interpreting the information and data obtained during an evaluation is to determine whether the data are valid – that is, did the examinee give a complete and accurate portrayal of symptoms and history, and did the examinee put forth appropriate effort on the tests? The same paper concludes that clinicians should be prepared to justify a decision not to assess symptom validity, and that in forensic contexts, where the incentive to mislead is higher, more extensive assessment is required.

The American Academy of Clinical Neuropsychology’s 2021 consensus statement reached a similar position: the validity of each test result should be evaluated proactively and thoroughly, in all clinical and forensic examinees – not only the ones who arouse suspicion.

This is not a matter of assuming the worst about people. It is the same logic that leads a laboratory to run controls alongside a blood sample.

Why it matters

The proportion of examinees who exaggerate or fabricate cognitive problems is not trivial, and it varies enormously by setting. A 2020 review in Archives of Clinical Neuropsychology summarizes published estimates ranging from under 10% in medical populations without external incentives, up to roughly 40% in personal injury and disability evaluations, and higher still in some Social Security, criminal, chronic pain, and ADHD-accommodation contexts.

Those numbers cut in two directions, and both matter. If validity is never assessed, genuinely invalid data can be presented as evidence of brain injury. But it also means that in ordinary clinical settings – a memory clinic, a stroke follow-up – most people are giving their honest best, and validity testing is what allows a clinician to say so with confidence. Well-documented effort is a finding that protects the patient.

What a failed validity test does and does not mean

Here the nuance is essential, and it is frequently lost in litigation.

Failing a validity measure is not the same as lying. A commissioned review prepared for the National Academies documents failure rates of roughly 11% to 30% among patients with independently established conditions such as multiple sclerosis, schizophrenia, epilepsy, and traumatic brain injury – people with no meaningful secondary-gain motive. In several of those studies, the validity measure appeared to be picking up a real feature of the disorder, such as impaired drive, motivation, or executive function, rather than deception. The same review notes that a patient could be deemed valid or invalid depending on which measure happened to be administered.

This is why the profession’s formal criteria for malingering are multidimensional. The 2020 update to the widely used Slick, Sherman, and Iverson framework requires an identified external incentive, converging evidence across sources, compelling inconsistencies, and – critically – explicit exclusion of alternative explanations. The NAN guidance similarly recommends a multi-method approach rather than a multi-test one, and cautions that performance slightly below a single cutoff may not justify any conclusion of biased responding at all.

A single below-cutoff score is a data point. It is not a verdict.

For patients

If you are scheduled for an evaluation, none of this should worry you. As Cleveland Clinic’s patient guidance notes, some tasks will feel easy and others hard, no one is expected to get everything right, and no one “fails.” Sleep well, take your usual medications, bring your glasses and hearing aids, and work as hard as you can throughout. That is genuinely all that is asked – and it is what makes the results useful to you.

The Brain Psychologist conducts comprehensive neuropsychological evaluations for clinical and forensic referrals, with validity assessment integrated throughout, in keeping with current professional standards.

Sources