OBJECTIVES: The authors examined Americans' opinions about financial and treatment competence of people with mental health problems, potential for harm to self or others, and the use of legal means to force treatment. METHODS: The 1996 General Social Survey provided interview data with a nationally representative sample (n = 1444). Respondents were given a vignette based on diagnostic criteria for schizophrenia, major depression, alcohol dependence, or drug dependence, or a "control" case. RESULTS: The specific nature of the problem was the most important factor shaping public reaction. Respondents viewed those with "troubles," alcohol dependence, or depression as able to make treatment decisions. Most reported that persons with alcohol or drug problems or schizophrenia cannot manage money and are likely to be violent toward others. Respondents indicated a willingness to coerce individuals into treatment. Respondent and other case characteristics rarely affected opinions. CONCLUSIONS: Americans report greater concern with individuals who have drug or alcohol problems than with persons who have other mental health problems. Evaluations of dangerousness and coercion indicate a continuing need for public education. (Authors)