Informed consent from cognitively impaired persons participating in research trials: comparative law observations.

This article addresses the ethical requirements to be considered when conducting clinical trials involving human subjects whose mental condition limits their ability to understand the information and to express fully autonomous and informed consent. It does not address other categories of vulnerable persons, such as children, or advanced directives concerning end-of-life care. There are many ethical issues entailed in clinical trials involving subjects with mental disabilities: how to obtain informed consent, balancing risks and benefits, balancing individual benefits with collective scientific and social interests, legal representation and many more. This article focuses on the issues surrounding the concept of minimal risk and the relationship between informed consent and risk. These issues are addressed with particular emphasis on the regulations adopted by the European Union and the federal government of the United States of America. The conclusion proposes a list of working criteria.