The MacArthur Treatment Competence Study. I

This is the first of three papers reporting the results of the MacArthur Treatment Competence Study, a project designed to develop reliable and valid information with which to address clinical and policy questions regarding the abilities of persons with mental illness to make decisions about psychiatric treatment. Four commonly applied legal standards for determining decision-making competence are described: abilities to communicate a choice, understand relevant information, appreciate the nature of the situation and its likely consequences, and rationally manipulate information. Previous research related to the capacities of persons with mental illness in relation to these standards is reviewed and critiqued. The principles underlying the design of the MacArthur Treatment Competence Study are described.This work was supported by the Research Network on Mental Health and the Law, John D. and Catherine T. MacArthur Foundation. The authors, are grateful to the members of the Network for their assistance in the conceptual development of this project and for their, comments on an earlier draft of this paper: Shirley Abrahamson, Richard Bonnie, Pamela Hyde, John Monahan, Stephen Morse, Ed Mulvey, Loren Roth, Paul Slovic, Henry Steadman, and David Wexler.