The association of specific neuropsychological deficits with capacity to consent to research or treatment

Informed consent is key to ethical clinical research and treatment, but partially rests on the ability of individual patients or research participants to use disclosed information to make a meaningful choice. Although the construct of decisional capacity emerged from legal and philosophical traditions, several investigators have begun examining the relationship of specific neuropsychological abilities to decisional capacity. This line of research may foster development of better consent procedures, as well as aid in refining the construct of decisional capacity toward a form that better reflects the underlying neurocognitive processes. We conducted a systematic search of the published literature and thereby identified and reviewed 16 published reports of empirical studies that examined the relationship between specific neuropsychological abilities and capacity to consent to research or treatment. Significant relationships between neuropsychological scores and decisional capacity were present across all the reviewed studies. The degree to which specific neuropsychological abilities have particular relevance to decisional capacity remains uncertain, but the existing studies provide a solid basis for a priori hypotheses for future investigations. These ongoing efforts represent an important conceptual and empirical bridge between bioethical, legal, and neuropsychological approaches to understanding meaningful decision-making processes.