Abstract: Mental disorders may compromise sufferers'capacity to understand the information presented and their ability to make a reasoned decision about participating in clinical research.Regarding clinical research in-volving individuals who by reason of mental disorders are not capable of giving adequately informed consent, Institutional Review Board should ensure that, such persons will not be subjects of research that might equally well be carried out on persons whose capacity to give adequately informed consent is not impaired;the purpose of the research is to obtain knowledge relevant to the particular health needs of persons withmental disorders;the consent of each subject has been obtained to the extent of that person's capabilities, and a prospective subject's refusal to participate in research is always respected, unless, in exceptional circumstances, there is no reasonable medical alternative and local law permits overriding the objection;and, in cases where prospective subjects lack capacity to consent, permission is obtained from a legally authorized representative in accordance with applicable law.

Key words: Ethics Committee, ethic review, disadvantaged groups, clinical test, cognitively impaired