How was optimism related to mortality before the rise in “deaths of despair” that began in the late 1990s? We show that as early as 1968 more optimistic people lived longer (using the Panel Study of Income Dynamics). The relationship depends on many factors including gender, race, health, and education. We then evaluate these and other variables as determinants of individual optimism over the period 1968-1975. We find women and African Americans were less optimistic at the time than men and whites (although this has changed in recent years). Greater education is associated with greater optimism and so is having wealthy parents. We then predict optimism for the same individuals in subsequent years, thus generating our best guess as to how optimism changed for various demographic groups from 1976-1995. We find people with less than a high school degree show the greatest declines in optimism, which along with their long-run links to premature mortality and deaths of despair, highlights the importance of better understanding optimism’s causes and consequences.