Faking in Competency to Stand Trial Evaluations: Professionals' Practices and Detecting Bias in Examiners' Reports.

• Author: Rubenzer, Steve

"There may be great fraud in this matter... (the judge) may do well to inquire... whether it (incompetence) be real or counterfeit." (Hale, 1736) (1)

A national survey of competency examiners estimated that 24% of defendants were feigning, and a further 10% were not presenting validly in other ways. (2) Feigning is a general term that means "faking bad" without specifying a motive. Malingering is the intentional production or gross exaggeration of symptoms for a tangible benefit. There are several other conditions (Factitious disorder, Somatoform disorders, Conversion disorder) that also imply invalid responding. Lack of full cooperation, without a clear motive and deliberate intent to perform badly, is also a major concern because tests and procedures psychologists use assume full engagement and effort on the part of the test-taker.

In the Oxford Best Practices series book on assessing competency to stand trial (CST), the author states, "Malingering must always be considered by any evaluator working within the forensic context" (p. 124). (3) This statement remains in force for defendants who have a legitimate mental condition, because even examinees with schizophrenia, (4) serious head injury, (3) and intellectual disability (6) can exaggerate their disabilities. There are only a few diagnoses that strongly imply impairment to the point of incompetence, such as delirium and moderate to severe dementia or intellectual disability.

Feigning can take many forms, some of which have not been previously emphasized in the professional literature. (7) These are shown in Table 1 on the following page.

Unsophisticated defendants often fake multiple issues and conditions, including psychosis, amnesia for the crime, intellectual limitations, and ignorance of the court system. More sophisticated malingerers will often portray a more specific condition, such as dementia or severe depression, and often have medical records that are superficially supportive. There is a myth among less sophisticated examiners that malingerers are easy to identify. This may be true of the feigners they have caught, but this may be a small fraction of those they encountered. As in most endeavors, it is a mistake to underestimate ones opponent.

MEANS OF ASSESSING NEGATIVE RESPONSE BIAS

Validity Testing

Validity testing refers to instruments and procedures designed to assess whether the examinee is presenting in a reliable, valid manner. There are two basic types of validity tests: Those that rely on the examinee's answers when asked about symptoms and problems, and those that rely on the examinee's performance on motor, cognitive or knowledge tasks.

1. Symptom Report Tests

   Many readers may already be familiar with the Minnesota Multiphasic Personality Inventory-2 (MMPI-2), (8) which is a 567-item true-false questionnaire about psychiatric symptoms. There are now two newer versions, the MMPI-2-Restructured Form (MMPI-2-RF) (9) and MMPI-3, both of which are over 200 items shorter and contain other changes from the prior version. All the MMPI variants are bristling with excellent response style scales that detect inconsistent responding, over-reporting, exaggeration, and defensiveness, and these scores are often not presented in reports. Scores on scales indicating exaggeration may be ignored or glossed over by unscrupulous experts. They should be more agreeable to releasing them to a psychologist designated by the prosecutor.

   Structured interviews resemble tests like the MMPI-2, but the items are read to the examinee and the examiner records and scores each response, and some observations are also recorded and scored. The Structured Inventory of Reported Symptoms (SIRS) (10) can identify about half of feigners with a low false positive rate (about 5%). (11) It was recently updated and revised (12) after findings that it was prone to false positive errors in some patient groups. New interpretive rules and categories were added, but these significantly reduced sensitivity so that only about one third of feigners are identified. (13) The Miller Forensic Assessment of Symptom Test (M-FAST) (14) is marketed as a screening test, but simply using a higher cutoff score (e.g., >11), the M-FAST can provide substantial evidence of over-reporting/exaggeration. (15)

2. Performance Validity Tests (PVTs)

   These tests require the examinee to "do" something, such as remember pictures or words, then provide answers that are objectively right or wrong. Memory testing is a common approach. One of the earliest, quickest, and most used performance validity tests (PVT) is...