Competency to stand trial research: Guidelines and future directions

Abstract

The adjudicative competency literature has been growing consistently since the early 1960s; however, there has been great variability in the research methods employed by researchers and the way in which findings have been presented. We recently conducted a meta-analysis which included 68 studies published between 1967 and 2008 comparing competent and incompetent defendants on a number of demographic, psychiatric, and criminological variables. The findings from our meta-analysis are presented elsewhere (Pirelli, G., Gottdiener, W.H., & Zapf, P.A. (2011). A meta-analytic review of competency to stand trial research. Psychology, Public Policy and Law. Online First Publication, January 17, 2011. doi: 10.1037/a0021713; however, based on our findings, we developed 13 competency research guidelines intended toserve as a reference for those conducting research in the area. The guidelines represent an effort to effectuate consensus in terms of methods utilized and comparability in terms of results presented. We also set forth three areas deemed promising for future study. The guidelines and future directions presented in this manuscript are not intended to be exhaustive, but rather a much needed point of consensus among researchers leading to the commencement of a new line of competency research.

Keywords:

• competency to stand trial
• capacity to stand trial
• adjudicative competency
• fitness to stand trial
• trial competency
• forensic mental health assessment
• forensic psychology

Notes

1. The terms competency to stand trial, adjudicative competency, and fitness to stand trial are used interchangeably throughout the manuscript to reflect the various terms employed across jurisdictions within the United States as well as among various countries (e.g. the United Kingdom and Canada).

2. A new assessment measure was published after the present meta-analysis was completed and this manuscript was written: the Inventory of Legal Knowledge (ILK; Musick & Otto, 2010). According to the description on the Professional Assessment Resources (PAR) Website, ‘The ILK is not a test of adjudicative competence. It is solely a measure of response style; more specifically, it is a measure of a defendant's approach to inquiries about his or her legal knowledge.’

3. It seems likely that Nicholson and Kugler (1991) incorporated these data into Table 7 of their meta-analysis, whereby they presented statistics on the proportion of defendants ‘passing’ or ‘failing’ the CST and three additional competency measures (i.e. GCCT, CAI, IFI), in which case a cumulative effect size was calculated without acknowledging that the combined studies employed dissimilar methods.

4. Nicholson and Kugler (1991) reported data on mental health professionals as a whole, but they believed ‘correlates of competency might vary as a function of the source of the competency determination’ (p. 367). Sources of the competency criterion used across studies were delineated in the present meta-analysis to include mostly psychiatrist(s) decisions (29%); followed by a combination of various individual decisions, or mixed, (25%); a mental health professional ‘team’ (21%); the court (19%); psychologist(s) (3%); not reported (3%). Source of competency decision was not found to be a significant moderator in the present meta-analysis; however, limited data were available and further research is needed in this regard.