The competence of cognitively vulnerable participants to consent to biomedical research.

Enhanced knowledge of the nature and causes of mental disorder and the neurogenetic basis of many conditions of youth and old age have led increasingly to a need for the recruitment of ‘cognitively vulnerable’ participants in biomedical research. These include adults with mental disorder or mental retardation and healthy adolescents whose decisional competence often falls in the ‘grey area’ between obvious competence and obvious incompetence. As a result, they may not be recognised as having the legal capacity to make such decisions themselves. At the core of the debate surrounding the ethics of participation of cognitively vulnerable participants in research is when, if at all, we should judge them decisionally competent to consent to or refuse research participation on their own behalf and when they should be judged incompetent in this respect. In this thesis, I develop a theoretical framework for making judgments about decisional competence to consent to biomedical research on behalf of five discrete groups of cognitively vulnerable individuals. I call this a framework a theory of precautionary task or decisional competence judgment (PTDCJ). It derives from precautionary moral reasoning informed by Alan Gewirth’s Principle of Generic Consistency (PGC) and is supported by empirical studies in psychiatry. Using this framework, I argue that we can make morally defensible judgments about the competence or incompetence of a potential participant to give contemporaneous consent to research by having regard to whether a judgment of competence would be more harmful to the generic rights of the potential participant (and any other agents concerned) than a judgment of incompetence. I also use this argument to justify an account of supported decision-making in research. I end the thesis by applying this framework to evaluate the extent to which this approach is evident in existing legal provisions and ethical guidelines in England and Wales and the United States.