Book excerpt: The MacArthur Competence Assessment Tool for Treatment (MacCAT-T) is the product of an 8-year study of patients' capacities to make treatment decisions. It is a semi-structured interview that assists clinicians in assessing a patient's competence to consent to treatment. The process provides a patient with information about their medical/psychiatric condition, the type of treatment being recommended, its risks and benefits, as well as other possible treatments and their probable consequences. During this process, the MacCAT-T prompts the clinician to ask questions that assess the patient's understanding, appreciation, and reasoning regarding treatment decisions.The MacCAT-T Manual is a large-format, examiner-friendly field manual for conducting actual competency assessments. The MacCAT-T Record Form is well designed for recording, rating, and summarizing patient responses. The training videotape, Administering the MacCAT-T, demonstrates an actual administration of the test with discussion, comments, and annotations by Drs. Grisso and Appelbaum.The book, Assessing Competence to Consent to Treatment, describes the place of competence in the doctrine of informed consent, analyzes the elements of decision making, and shows how assessments of competence to consent to treatment can be conducted within varied general medical and psychiatric treatment settings. Includes numerous case studies.