A state cannot constitutionally confine a non-dangerous individual who is capable of surviving safely in freedom by themselves or with the help of willing and responsible family members or friends. Decided June 26, 1975 (argued January 15, 1975). Opinion of the Court: Potter Stewart → go there Applied: the Fourth Amendment → go there Applied: the Fourteenth Amendment → go there Topic: Restrictions on involuntary commitment. O'Connor v. Donaldson, 422 U.S. 563 (1975), was a landmark decision of the US Supreme Court in mental health law. It ruled that a state cannot constitutionally confine non-dangerous individuals who are capable of surviving safely in freedom by themselves or with the help of willing and responsible family members or friends. Since the trial court jury found, upon ample evidence, that petitioner did so confine respondent, the Supreme Court upheld the trial court's conclusion that petitioner had violated respondent's right to liberty. The case was important in the deinstitutionalization movement in the United States. Wiki link