Cruzan v. Director, Missouri Dept. of Health is a landmark U.S. Supreme Court case from 1990 that addressed the right to die and the withdrawal of life-sustaining treatment for individuals in persistent vegetative states. The Court ruled that while individuals have a right to refuse medical treatment under the Due Process Clause of the Fourteenth Amendment, states may require clear and convincing evidence of a patient's wishes regarding life support before allowing withdrawal of such treatment.