MacArthur Competence Assessment Tool (MacCAT-CA)
The Basics: The MacCat-CA was designed specifically to test a defendant’s psychological abilities relevant to competence to proceed. The test is a broader inquiry into competency issues including insight into rational thinking, understanding and recognition of relevant information. The test consists of 22 questions and takes about 30 minutes to complete. The first 16 questions are based on a defendant’s understanding of a short story of two men who get into a fight. The last 6 questions are specifically geared to test a defendant’s understanding of his own circumstances.
Strengths and Weaknesses: Unlike other competency tests, the MacCAT-CA includes a distinction between the defendant’s current legal knowledge and his capacity to obtain such knowledge.
Critical Issues: Because the reasoning scale is based on a hypothetical story, the defendant may be more or less reasonable when the outcome affects him directly. It’s important to determine whether or not a defendant’s competency extends to hypothetical situations, as well as his own. (text from wordpress.com)
Dr. Marvin Acklin comments; “The MacCAT-CA, developed by the MacArthur Foundation Research Network on Mental Health and the Law, is the queen of CST instruments. The 22-item measure assesses three Dusky-derived competence-related abilities: understanding, reasoning, and appreciation. The instrument was normed on adult defendants. Defendant’s capacities are assessed through responses to a series of vignettes. Scores for each vignette are summed and compared to three groups of defendants (N = 729), including unscreened jail inmates, jail inmates receiving mental health services, and hospitalized incompetent defendants. Normative interpretation of MacCAT-CA scores include minimal/none, mild, and clinically significant impairment. The psychometrics of the measure is well detailed in the manual. Although the vignette methodology has received some criticism, in this reviewer’s opinion, the primary strength of the measure is the opportunity to evaluate the quality of the defendant’s reasoning: the basis for decisional competency. The open response format seems particularly sensitive to the infiltration of impaired reasoning. The professional manual provides a conceptual background for the instrument and detailed exposition of norms, reliability, and validity information. The administration time typically requires 25–45 minutes.” Marvin W. Acklin, Ph.D. (December 13, 2010. www.hawaiiforensicpsychology.com)