Evaluation of decision-making capacity in patients with Alzheimer's disease and Dementia with Lewy bodies

BACKGROUND: Decision-making capacity is a high executive function which refers to make sensible choices. Dementia is known as a syndrome which mainly affects executive functions. When it comes to clinical research, there are not enough researches investigates decision-making capacity in dementia. OBJECTİVES: To evaluate the capacity to consent in patients with early stage Alzheimer's Disease (AD) and early stage Dementia with Lewy Bodies. METHOD: 54 subjects with early-stage Alzheimer's Disease (n=23) and early stage Dementia with Lewy Bodies (n=15) and healthy controls (n=16) were included in this study. "Clinical Insight Rating Scale (CIRS)" was used for assessment of insight in patients with early-stage AD and early stage DLB. "Addenbrooke Cognitive Evaluation-Revised (ACE-R)" was applied to assess patients and healthy controls cognitive functions and "MacArthur Capacity To Consent-Clinical Research (MacCAT-CR)" was applied to assess capacity to consent. Dunn's Posthoc Multiple Comparisons Test was used to compare cognitive functions tests and capacity to consent for statistical analysis. Correlation between the scores of all tests and MacCAT-CR were investigated with the Spearman Correlation Analyses method. RESULTS: Based on MacCAT-CR, the decision-making capacity was found correlated with ACE-R scores and subtests of ACE-R (attention and orientation, memory and visual-spatial functions) in the AD group. ACE-R scores and subtest scores of ACE-R (attention and orientation, verbal fluency and language) also were found correlated with MacCAT-CR scores in the DLB group. However, there was no statistical significance between the AD group's and the DLB group's MacCAT-CR scores. Furthermore, there was also no correlation between AD group's and the DLB group's MacCAT-CR scores and CIRS scores. DISCUSSION: Decision-making capacity of clinical research was impaired both in early-stage AD and early stage DLB. Furthermore, this impaired decision-making capacity was found related to the deficiency in attention and orientation, memory, verbal fluency and visual-spatial functions.