If a person under the age of 18 refuses to consent to treatment, it is possible in some cases for their parents or the courts to overrule their decision. However, this right can be exercised only on the basis that the welfare of the young person is paramount. In this context, welfare does not simply mean their physical health. The psychological effect of having the decision overruled would have to be taken into account and would normally be an option only when the young person was thought likely to suffer "grave and irreversible mental or physical harm". Usually, when a parent wants to overrule a young person's decision to refuse treatment, health professionals will apply to the courts for a final decision.