In most cases, a mentally disabled person has an appointed guardian authorized to make medical decisions and give informed consent for that individual. Medical providers need to make sure that when they obtain informed consent for incompetent individuals, they have obtained it from the correct person or persons.
In most situations, parents can give informed consent for treatment for their minor children. However, some states allow young adults under eighteen to play a more active role in their medical care and treatment, including the process of informed consent. Not every teenager is capable, however, of making informed consent decisions under these laws. Instead, most states focus on “mature minors” capable of understanding the nature and consequences of treatment. In those states, such young adults may be able to provide consent without consulting with their parents. For example, some states have passed specific laws that allow for minors to consent, without parental knowledge or approval, to health care treatments related to substance abuse, mental health and sexual activity.