Americans are becoming more miserable, and lack of health insurance is one reason why, according to a survey by the University of Chicago’s National Opinion Research Center. The center interviewed 1,340 Americans for a report entitled “Troubles in America: A Study of Negative Life Events across Time and Sub-Groups,” as part of its semiannual General Social Survey. Subjects were asked whether they had experienced trouble in any of 58 categories within eight domains such as health, work and finances. Participants could also volunteer woes that did not fit into the questionnaire.