Reliance on performance validity tests administered by psychiatrists

 

Commentary

This is a very important judgment for psychiatrists and psychologists who employ validity testing when assessing litigants. There were two experts, both psychiatrists. One employed validity tests. The other did not and she professed no experience of their use. The psychiatrist who employed them was a registered user of the tests for the administration of which he had been trained and had paid for a licence.

Reliance on the results of validity testing was called into question for a number of reasons:

• There were contextual limitations specifically regarding psychological and physical health variability, the potential for bias, a possible overemphasis of malingering detection and a potential lack of holistic assessment.

• The defendant sought to advance expert evidence as that of a neuropsychologist, which the defendant’s expert was not.

• The use of so many tests within a medico legal context, particularly when administered by a defendant psychiatric expert may have led to a lack of holistic assessment.

• The claimant’s performance could have been impacted by his dyslexia.

• The validity testing results was evidence that was not admissible as expert evidence.

• If it was admissible, permission to adduce this particular form of expert evidence, given that qualification as a psychiatrist does not automatically provide the expertise necessary to administer the tests, should not have been granted.

• If it was admissible, it was unfair and should be treated with caution or disregarded.

• There had been unjustified and inappropriate non disclosure of the tests and answers given.

• This evidence did not, because the expert was neither a psychologist or neuropsychologist, have the ability to explain fairly the range of opinion on the subject of validity testing in compliance with CPR 35 PD (6): where there is a range of opinion on the matters dealt with in the report –(a) summarise the range of opinions.

• Not putting the tests into the public domain impacts upon the evidential and probative value of the outcome of the tests within an adversarial court setting.

• The claimant's legal representatives had been limited to the extent to which they had been able to probe, question or challenge that opinion evidence, again, because they had been denied sight of, or an understanding of, the underlying material upon which it was based.

• An expert's report must give details of any literature or other material which has been relied on in making the report which can be considered to include the questions and answers that Claimant gave.

• In the absence of an application for permission to rely upon this type of expert evidence, there was a risk of disadvantage to the other party, particularly when that was combined with the limited disclosure of the tests and responses given by the Claimant.

• There was, at least, a real possibility that there were different views as to consensus as to the reliability of validity testing in the UK, albeit that it is more widely used in North America.

Psychologists have more experience of administering validity tests and a further commentary on this case is being sought from an experienced psychology expert. Advice for psychologists is to be found in Guidance on the assessment of performance validity in neuropsychological assessments (https://cms.bps.org.uk/sites/default/files/2022-07/Guidance%20on%20the%20assessment%20of%20performance%20validity%20in%20Neuropsychology%20assessments.pdf )

In the meantime, psychiatrists who intend to use validity testing are advised to inform their instructing solicitors in order that they can consider advising the adverse party and / or the court. This will provide the opportunity for the court to consider whether such evidence is admissible and, if it is, ensure that the adverse party, if it wishes to do so, can instruct a neuropsychologist or suitably qualified psychiatrist.      

Learning point

• When assessing a subject, have regard to and be prepared to explain the possible effects of the subject feeling rushed, feeling the assessment oppressive, or considering questions inappropriate or intrusive.

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