An issue of ongoing concern to clinical investigators, medical ethicists, and institutional review board members is the problem of obtaining informed consent in research that involves people with mental illness as research participants. Although the presence of a mental disorder per se does not render a person incapable of giving informed consent, some individuals afflicted with significant cognitive impairment, formal thought disorder, substantial anxiety or depression, or a variety of other symptoms may be impaired in their capacity to comprehend consent (...) disclosures and therefore to exercise consent to research participation in a competent manner.The stakes surrounding this informed consent issue are significant. On the one hand, the inclusion in research of participants who are not capable of giving informed consent may result in their exposure to unwarranted risks and significant harm. These concerns may be exacerbated in certain clinical trials in which patients are required to discontinue their medications during “washout periods” at the onset of a study, or are randomly assigned to a placebo treatment and remain off medication for extended periods. (shrink)