OBJECTIVES:Optimizing the research consent process simultaneously fosters respect for autonomy and protection of those with diminished capacity for autonomy. This study evaluated the effectiveness of an enhanced research consent procedure, employing multimedia disclosure and corrective feedback, in improving decisional capacity among 114 people with mild-to-moderate Alzheimer's disease (AD) and 134 non-psychiatric comparison (NC) subjects. METHODS:Participants were randomized to consent type (routine versus enhanced) and protocol type (lower versus higher risk). Outcomes included a 5-item questionnaire assessing immediate comprehension, MacArthur Competence Assessment Tool for Clinical Research assessing four components of decision-making capacity, and categorical decisional capacity (based on a cut-score established in reference to expert judgments for a subset of participants). RESULTS:There was no significant effect of the enhanced consent procedure, relative to routine consent, on immediate comprehension or decisional capacity. CONCLUSIONS:Multimedia tools do not appear to be the solution to better consent for AD research. CLINICAL IMPLICATIONS:Given the ethical primacy of informed consent and issues of justice for impaired populations who might be harmed by an absence of research-based treatment advances, continued search for ways to more meaningfully engage people with AD in the consent or assent process is warranted.