The MacArthur Competence Assessment Tool for Treatment (MacCAT-T) is an instrument designed to assess decision-making capacity. Designed as part of the MacArthur Competence Treatment Competence Study, a multiyear, multisite effort named for the well-known philanthropic foundation, the tool operationalizes established elements of competent decisions. The semistructured instrument, which can be completed within 20 to 30 minutes, guides clinicians through the discussion of a specific treatment decision and scores responses on four separate scales.

Structured disclosures assess patients’ understanding, reasoning, appreciation, and choice, the four elements of decision making established in reviews of the established legal and ethical literature. For understanding, patients are tested on their comprehension of the nature of their illness, recommended treatment, alternatives, and risks and benefits. Reasoning evaluates patients’ problem-solving ability when faced with a specific treatment choice. Appreciation assesses acknowledgment of illness and the potential value of treatment, while choice determines whether patients make a selection consistent with their reasoning.

Intended for the comparison of patient groups, the MacCAT-T has been tested in a variety of populations, including patients diagnosed with schizophrenia, psychosis, dementia, and depression. It has shown strong interrater reliability and good agreement with the assessment of clinicians.

The MacCAT-T has been instrumental in demonstrating important correlations between symptoms,cognitive variables, and decision-making capacity. In a number of studies, it has underscored the relevance of specific variables such as thought disorganization and attention while demonstrating that patients with mental illness nonetheless overlap with control populations in many of their abilities.

Criticized for its reliance on a cognitive-based assessment of capacity, the instrument does in fact go beyond cognition in its assessment. The appreciation standard, for example, is more than a simple cognitive standard, including, as it does, the treatment’s significance and relevance to the patient. Moreover, even emotional capacity relies on cognition to assess the meaningfulness of a situation. Indeed, in one direct comparison of capacity assessment tools, the MacCAT-T was clearly found to address the common construct underlying different competence standards.

One of a number of semistructured interviews to come out of the MacArthur studies, the MacCAT-T is now part of an entire generation of commonly used tools assessing specific decision-making capacities.


  1. Appelbaum, P. S., & Grisso, T. (1988). Assessing patients’ capacities to consent to treatment. New England Journal of Medicine, 319(25), 1635-1638.
  2. Grisso, T., Appelbaum, P. S., & Hill-Fotouhi, C. (1997). The MacCAT-T: A clinical tool to assess patients’ capacities to make treatment decisions. Psychiatric Services, 75(11), 1415-1419.
  3. Vollmann, J., Bauer, A., Danker-Hopfe, H., & Helchen, H. (2003). Competence of mentally ill patients: A comparative empirical study. Psychological Medicine, 33(8), 1463-1471.

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