The ability of persons with Alzheimer disease (AD) to make a decision about taking an AD treatment

Objective: To examine the severity of impairments in the decision-making abilities (understanding, appreciation, reasoning, and choice) and competency to make a decision to use an Alzheimer disease (AD)-slowing medication in patients with AD and the relationships between these impairments, insight, and overall cognition. Methods: Semistructured in-home interviews were conducted with 48 patients with very mild to moderate AD and 102 family caregivers of patients with mild to severe AD recruited from the Memory Disorders Clinic of an AD center. The interview measured performance on the decision-making abilities and three expert psychiatrists' judgment of competency based on their independent review of the patient interviews. Results: There was considerable variation in patients' performance on the measures of decision-making abilities. Three expert raters found 19 of 48 (40%) of the subjects competent. Competent patients were more likely to show awareness of their symptoms, prognosis, and diagnosis. A sensitivity analysis suggests that a MMSE score is helpful in discriminating capacity from incapacity only when below 19 or above 23. Conclusions: Persons with mild to moderate Alzheimer disease (AD) have notable impairments in their ability to make an AD treatment decision, especially persons with moderate AD and persons who lack awareness of symptoms, prognosis, or diagnosis.