Updated May 2004
In recent decades, the laws of the United States, United Kingdom, and many other nations have affirmed that people with mental disorder have the right to give or withhold consent for their treatment. Only if their decision-making abilities are seriously impaired may they be declared legally incompetent to make such decisions, which then will be made for them by courts or others appointed to decide on their behalf.
Little has been known, however, about the extent to which mental disorders may impair people's abilities to make treatment decisions. To the extent that they do, two concerns are raised. One is the danger that some people's poor decisionmaking abilities may cause them to refuse treatments that they need and that they would have wished to obtain if they had had the capacity to comprehend the treatment's benefits. The other concern is that disabilities in decision-making might cause some people to accept certain treatments that they might otherwise refuse if they were capable of comprehending the treatment's implications.
In the absence of reliable information, some professionals and policy makers have claimed that mental disorders invariably impair decisionmaking sufficiently to consider people with mental disorder legally incompetent to make treatment decisions. Some patient advocates, on the other hand, have argued that people with mental disorders are as capable as people without them to make legally enforceable treatment decisions.
The MacArthur Treatment Competence Study, supported by the Research Network on Mental Health and the Law of the John D. and Catherine T. MacArthur Foundation, was designed to provide information to policy makers and clinicians to help them address questions about the decision-making capacities of people who are hospitalized with mental illness. During its initial phase, beginning in 1988, the project developed interview procedures to measure abilities that the legal system has identified as relevant to decisionmaking competence. The four legally-relevant abilities that we addressed were the abilities to state a choice, to understand relevant information, to appreciate the nature of one's own situation, and to reason with information.
Following this pilot testing, the full-scale study was conducted with 498 participants recruited from three sites: Worcester, MA, Pittsburgh, PA, and Kansas City, MO. These included several groups: patients recently hospitalized with mental illness (either schizophrenia or major depression) or medical illness (ischemic heart disease: "unstable angina"); and non-patients recruited from the community for comparison purposes. Patients' decisionmaking abilities were assessed between two to seven days after their admission to hospitals.
The following findings were among the study’s most important results:
These results have several important implications for policy makers and clinicians:
During the final phase of the MacArthur Treatment Competence Study, we developed and tested an easy-to-use interview for assessing patients' decisionmaking abilities. Called the MacArthur Competence Assessment Tool-Treatment (MacCAT-T), this procedure is flexible enough to be applied by clinicians in day-to-day care of patients with varied disorders, yet is sufficiently standardized to provide ratings of patients' capacities of all four of the legally-relevant abilities examined in the earlier research study. The manual for the MacCAT-T is now available from: Professional Resource Press, P.O. Box 15560, Sarasota, FL 15560 (1-800-443-3364; www.prpress.com), in addition to interview and rating forms and a demonstration videotape.
The format of the MacCAT-T has been adapted for the assessment of decisionmaking capacity in other contexts, as well. The most frequently used of these is the MacCAT-CR, designed to assess potential subjects' capacities to consent to participation in clinical research. Preliminary studies have indicated that considerable impairment may exist in subjects with schizophrenia, but may be greatly ameliorated by special efforts to convey the material needed for an acceptable consent. Moderately depressed subjects, in contrast, have not demonstrated substantial impairment with the instrument.
The MacCAT-CR is being used in many sites for screening research subjects and for further investigation of subjects' capacities to consent to research participation. It is also available from Professional Resource Press.
Other versions of instruments based on the MacCAT format
have been developed, including measures for assessing the capacities
of persons to complete a health care proxy, to complete a psychiatric
advance directive, and to make decisions about continuing to drive
(especially relevant for the elderly).
Appelbaum, P.S., & Grisso, T. (1995). The MacArthur Treatment Competence Study: I. Mental illness and competence to consent to treatment. Law and Human Behavior, 19, 105-126.
Grisso, T., Appelbaum, P.S., Mulvey, E., & Fletcher, K. (1995). The MacArthur Treatment Competence Study: II. Measures of abilities related to competence to consent to treatment. Law and Human Behavior, 19, 127-148.
Grisso, T., & Appelbaum, P.S. (1995). The MacArthur Treatment Competence Study: III. Abilities of patients to consent to psychiatric and medical treatment. Law and Human Behavior, 19, 149-174.
Appelbaum, P.S., & Grisso, T. (1988). Assessing patients' capacities to consent to treatment. New England Journal of Medicine, 319, 1635-1638.
Appelbaum, P.S., & Grisso, T. (1997). Capacities of hospitalized medically ill patients to consent to treatment. Psychosomatics, 38, 119-125.
Berg, J., Appelbaum, P.S., & Grisso, T. (1996). Constructing competence: Formulating standards of legal competence to make medical decisions. Rutgers Law Review, 48, 345-396.
Grisso, T., & Appelbaum P.S. (1994). Comparison of standards for assessing patients' capacities to make treatment decisions. American Journal of Psychiatry, 152, 1033-1037.
Grisso, T., & Appelbaum, P.S. (1991). Mentally ill and non-mentally ill patients' abilities to understand informed consent disclosures for medication: Preliminary data. Law and Human Behavior, 15, 377-388.
Grisso T., & Appelbaum, P.S. (1995). MacArthur Treatment Competence Study. Journal of American Psychiatric Nurses Association, 1, 125-127.
Grisso, T., & Appelbaum, P.S. (1996). Values and limits of the MacArthur Treatment Competence Study. Psychology, Public Policy, and Law, 2, 167-181.
Grisso, T., & Appelbaum, P.S. (1997). The MacCAT-T: A clinical tool to assess patients' capacities to make treatment decisions. Psychiatric Services, 48, 1415-1419.
Grisso, T., & Appelbaum, P.S. (1998). Assessing Competence to Consent to Treatment: A Guide for Physicians and Other Health Professionals. New York: Oxford University Press.
Appelbaum, P.S., & Grisso, T. The MacArthur Competence Assessment Tool for Clinical Research (MacCAT-CR). (2001). Sarasota, FL, Professional Resource Press.
Grisso, T., & Appelbaum, P.S. (1998). MacArthur Competence Assessment Tool for Treatment ( MacCAT- T). Sarasota, FL: Profes sional Resource Press.
Grisso, T., & Appelbaum, P.S. (1993). Thinking Rationally About Treatment. Worcester, MA: University of Massachusetts Medical Center.
Grisso, T., & Appelbaum, P.S. (1992). Understanding Treatment Disclosures. Worcester, MA: University of Massachusetts Medical Center.
Appelbaum, P.S., & Grisso, T. (1992). Perceptions of Disorder. Worcester, MA: University of Massachusetts Medical Center.
Studies Using the MacCAT-T
Appelbaum, P.S., Grisso, T., Frank, E., O’Donnell, S., & Kupfer, D.J. (1999) Competence of depressed patients for consent to research. American Journal of Psychiatry, 156, 1380-1384.
Palmer, B.W., Nayak, G.V., Dunn, L.B., Appelbaum, P.S., & Jeste, D.V. (2002) Treatment-related decision-making capacity in middle-aged and older patients with psychosis: a preliminary study using the MacCAT-T and HCAT. American Journal of Geriatric Psychiatry, 10,207-211.
Gilman, R.B., & Billick, S.B. Assessing capacity instruments in inpatient legal proceedings. (2003). American Journal of Forensic Psychiatry, 24, 45-52.
Lapid, M.I., Rummans, T.A., Poole, K.L., Pankratz, S., Maurer, M.S., Rasmussen, K.G., Philbrick, K.L., & Appelbaum, P.S. Decisional capacity of severely depressed patients requiring electroconvulsive therapy. (2003). The Journal of ECT, 19, 67-72.
Tan, J., Hope, T., & Stewart, A. Competence to refuse treatment in anorexia nervosa. (2003). International Journal of Law and Psychiatry, 26, 697-707.
Vollman, J., Bauer, A., Danker-Hopfe, H., & Helmchen, H. Competence of mentally ill patients: a comparative empirical study. (2003). Psychological Medicine, 33, 1463-1471.
Lapid, M., Rummans, T., Pankratz, S., & Appelbaum, P.S. Decisional capacity of depressed elderly to consent to electroconvulsive therapy. (2004). Journal of Geriatric Psychiatry and Neurology, 17, 42-46.
Studies Using the MacCAT-CR
Carpenter, W.T., Gold, M.J., Lahti, A.C., Queern, C.A., Conley, R.R., Bartko, J.J., Kovnick, J., & Appelbaum PS. (2000). Decisional capacity for informed consent in schizophrenia research. Archives of General Psychiatry, 57, 533-538.
Kim, S.Y.H., Caine, E.D., Currier, G.W., Leibovici, A., & Ryan, J.M. (2001). Assessing the competence of persons with Alzheimer’s disease in providing informed consent for participation in research. American Journal of Psychiatry, 158 , 712-717.
Kim, S.Y.H., Cox, C., Caine, E.D. Impaired decision-making ability in subjects with Alzheimer’s disease and willingness to participate in research. (2002). American Journal of Psychiatry, 159, 797-802.
Karlawish, J.H.T., Casarett, D.J., & James, B.D. Alzheimer’s disease patients’ and caregivers’ capacity, competency, and reasons to enroll in an early-phase Alzheimer’s disease clinical trial. (2002). Journal of the American Geriatric Society, 50, 2019-2024.
Moser, D.J., Schultz, S., Arndt, S., Benjamin, M.L., Fleming, F.W., Brems, C.S., Paulsen, J.S., Appelbaum, P.S., & Andreasen, N.C. Capacity to provide informed consent for participation in schizophrenia and HIV research. (2002). American Journal of Psychiatry, 159, 1201-1207.
Kovnick, J.A., Appelbaum, P.S., Hoge, S.K., & Leadbetter, R.A. Competence to consent to research among long-stay inpatients with chronic schizophrenia. (2003). Psychiatric Services, 54, 1247-1252.
Casarett, D.J., Karlawish, J.H.T., & Hirschman, K.B. Identifying ambulatory center patients at risk of impaired capacity to consent to research. (2003). Journal of Pain and Symptom Management, 26, 615-624.
Moser, D., Arndt, S., Kanz, J.E., Benjamin, M., Bayless, J.D., Reese, R.L., Paulsen, J.S., & Flaum, M.A. Coercion and informed consent in research involving prisoners. (2004). Comprehensive Psychiatry, 45, 1-9.
(1) The Working Group responsible for conducting this research consists of Paul S. Appelbaum, M.D., and Thomas Grisso, Ph.D. Requests for further information should be sent to either author at the Department of Psychiatry, University of Massachusetts Medical School, Worcester, MA 01655 (e-mail: AppelbaP@ummhc.org; Thomas.Grisso@umassmed.edu).