Commentary: Competently Assessing Competence to Stand Trial Can Be Trying

Competence to stand trial (CST) has historically been a difficult problem to grapple with, if only for the reason that it is a subjective question being decided in a forum where objectivity is viewed as the ideal. This has doubtless been partly why there have been numerous attempts to make the process of assessing CST more objective, spawning several instruments in the process. Pinals et al.¹ briefly review these previous attempts and rightly highlight the deficiencies of the “first generation” of instruments. Their paper principally relates to one of the “second-generation” instruments, the MacArthur Competence Assessment Tool-Criminal Adjudication (MacCAT-CA) and attempts to take it out of the rarefied atmosphere of the research world and into the real world of clinical practice.

It is noteworthy that this study involved no distinction between the clinical evaluator of CST and the administrator of the MacCAT-CA. There may be a potential for bias in both assessments that could affect the generalizability of the finding, something the authors have been careful to acknowledge. This possibility assumes significance, however, when one realizes that the same reasons that preclude individual defendants from completing the MacCAT-CA might also make them incompetent to stand trial (severe thought disorganization, pressured speech, cognitive limitations). Also, previous research² has addressed some of the limitations raised in this article, such as language difficulties and ease of administration.

What is intriguing about the article by Pinals and her colleagues is the way it seeks to highlight the strengths and weaknesses of the MacCAT-CA as an instrument for use in clinical practice. It may well help to elicit useful information from paranoid defendants and to assist in the detection of malingering, but this aspect needs more research, particularly taking into account the effect of the extent of previous contact with the criminal justice system. James et al.³ described an inability to give valid instructions to counsel as being one of the two most likely reasons for defendants’ being incompetent to stand trial, and Pinals and her colleagues¹ properly identify the MacCAT-CA’s difficulty in adequately detecting this inability as a weakness in its use in clinical practice. Encapsulated delusions are also mentioned as an area in which the MacCAT-CA has limitations as a clinical tool, but all these points reinforce an even more fundamental truth, which is also recognized by the authors: none of these instruments should be viewed as an alternative to rigorous clinical assessment. Case 3 perhaps best illustrates why this is so. The resolution of florid psychotic symptoms may not lead to an improvement in MacCAT-CA scores, which in turn does not necessarily imply a lack of CST. Previous work relating to a derivative of the MacCAT-CA² has shown that global score on instruments such as the Brief Psychiatric Rating Scale (BPRS) may not be the best way of correlating severity of symptoms with CST, and that subscale scores might be more helpful.

A key question, relevant to further research, is the extent of the effect that residual cognitive difficulties arising from severe mental illness have on determining CST, as opposed to the effect of the symptoms of the illnesses themselves. It would also be useful to speculate on whether it is possible to distill instruments such as the MacCAT-CA to fewer items, making it easier to administer, without losing its construct validity, psychometric properties, and predictive utility. Finally, Pinals and her colleagues conclude with the sage advice that “evaluators of all disciplines would do well to maintain an awareness of developments in this area and to understand the strengths and limitations of these measures” (Ref. 1, p 187).

• American Academy of Psychiatry and the Law