The Mental Capacity Act requires that legally authorized representatives provide consent for individuals with diminished capacity.
While the regulations allow for legally authorized representatives to make substituted decisions for individuals who need assistance, researchers should obtain consent from the participants as far as possible. For individuals who may be only temporarily or intermittently incapacitated (e.g. due to injury or medications), researchers should attempt to approach these individuals at a time when they do have the capacity to consent to research. If a participant regains the capacity to consent to research after the research has begun, researchers should obtain the participant's informed consent before continuing his or her participation in the project.