Informed Consent appears to used only within the Health Care context and LDAPWiki sees this as at least closely related to Express consent
An Informed Consent can be said to have been given based upon a clear appreciation and understanding of the facts, implications, and consequences of an action. To give Informed Consent, the individual concerned must have adequate reasoning faculties and be in possession of all relevant facts. Impairments to reasoning and judgment that may prevent Informed Consent include basic intellectual or emotional immaturity, high levels of stress such as PTSD or a severe intellectual disability, severe mental illness, intoxication, severe sleep deprivation, Alzheimer's disease, or being in a coma.
Some acts can take place because of a lack of Informed Consent. In cases where an individual is considered unable to give Informed Consent, another person is generally authorized to give Informed Consent on his behalf, e.g., parents or legal guardians of a child (though in this circumstance the child may be required to provide Informed Consent) and conservators for the mentally ill.
In cases where an individual is provided insufficient information to form a reasoned decision, serious ethical issues arise. Such cases in a clinical trial in medical research are anticipated and prevented by an ethics committee or Institutional Review Board.