Relationship Between Cognitive Functions and Decision-Making Capacity in Older Institutionalized Patients with Schizophrenia: A Preliminary Study

Norio Sugawara,1– 3 Norio Yasui-Furukori,1,3 Sonoko Yamada,3 Mei Aoki,3 Yoshitaka Takeuchi,1,4 Kensuke Miyazaki,5 Kazutaka Shimoda1 1Department of Psychiatry, Dokkyo Medical University School of Medicine, Tochigi, Japan; 2Department of Clinical Epidemiology, Translational Medical Center, National Center of Neurology and Psychiatry, Tokyo, Japan; 3Department of Neuropsychiatry, Hirosaki University, School of Medicine, Aomori, Japan; 4Shiseikai, Takizawa Hospital, Tochigi, Japan; 5Department of Neuropsychiatry, Hirosaki-Aiseikai Hospital, Aomori, JapanCorrespondence: Norio Sugawara, Department of Psychiatry, Dokkyo Medical University School of Medicine, 880 Kitakobayashi, Mibu, Tochigi, 321-0293, Japan, Tel +81-28-287-2153, Fax +81-28-286-5187, Email nsuga3@dokkyomed.ac.jpBackground: Decision-making capacity for patients with psychiatric disorders is an important and controversial issue in clinical care settings. The aim of this study was to (1) evaluate the level of decision-making capacity of older institutionalized patients suffering from schizophrenia and (2) determine whether their diminished capacity is associated with specific aspects of cognitive impairment.Methods: Using a cross-sectional design, we recruited 48 older institutionalized patients (mean age ± standard deviation: 60.0 ± 14.0 years) who were diagnosed with schizophrenia. Participants underwent the assessments by the MacArthur Competence Assessment Tool for Treatment (MacCAT-T) and the Japanese version of the Brief Assessment of Cognition in Schizophrenia (Japanese-BACS).Results: The understanding summary scores of the MacCAT were found to have a significant positive correlation with the attention and verbal fluency subscale scores of the Japanese-BACS and negative correlations with age and duration of illness. In addition, the appreciation and reasoning summary scores had a significant negative correlation with age. In a linear regression model with a stepwise selection procedure, age, sex, and verbal fluency subscale scores were ...