In fact, they should go out of their way to address potential misunderstandings. Individuals with severe cognitive or psychiatric disorders that interfere with decision-making capacity generally cannot take part in research without consent from an appropriate agent or legally authorized representative. When dealing with such individuals as research participants, it is essential that the informed consent process include procedures for determining their ability to consent to participate. These determinations must be made in writing by someone not involved in the research. Deception or withholding information is rarely acceptable.
Informed consent requires that the potential participant understand what is to be done in the study.
Under most circumstances it is inappropriate to hold back information, and it is always wrong to mislead subjects in order to get them to participate. Occasionally, some minor deception might be needed to prevent bias in results. This can be acceptable with prior approval of the IRB, but subjects must be fully debriefed after participation. When deception is to be used, the consent form will have somewhat different information than the research protocol and this must be clearly explained in the research protocol. A clear specification of risks and benefits is needed.