This article discusses research in the field of mental health, examining the ethical is sues involved and the use of Informed Consent. In order to achieve these objectives two main approaches were used: (1) a brief history of the different treatments and research with patients with mental illness or disability; (2) theoretical and conceptual analysis of the main problems concerning the mental health field, namely the notion of vulnerability, responsibility and autonomy and the use of placebo control groups. Two main questions prompted the reflection on whether the patient with a mental disorder can sign an Informed Consent, and whether the use of a placebo is acceptable. The existence of antagonistic and contradictory positions indicates that mental health research is hampered by biases that are difficult to overcome. Ethical investigation that may contribute to the healing of mental disorders should not however be overlooked merely because of the difficulties involved in its implementation. It must be borne in mind that changes occurring in the context of Psychiatric Reform in Brazil are gradually altering archaic concepts about what constitutes mental illness and how this group should be understood and treated.
Bioethics; Research on vulnerable subjects; Mental disorders; Mental illness; Use of a placebo; Autonomy