Risk factors for the onset of depression in middle age and later life.

Using prospectively gathered data to study first-time occurrence of major depression rather than its persistence, this inquiry tested whether the risk of major depression might be elevated among middle-aged and older adults who were not currently working for pay and among those with less than 12 years of schooling. Diagnostic interviews were administered 1 year apart to identify incident cases of major depression among 7,737 continuing participants of the Epidemiologic Catchment Area Program aged 40 years and older. After all subjects were sorted into risk sets by age and residence census tract, and after persons with a prior history of major depression were excluded, in 162 risk sets, there were 180 incident cases as well as 960 subjects at risk for future occurrence of major depression. The estimated risk for persons not currently working for pay was not reliably greater than the level of risk for those currently working for pay [estimated relative risk (RR) = 1.48; 95% confidence interval (CI), 0.85-2.56]. Compared with adults who had 12 or more years of schooling, those who had less schooling were at increased risk (RR = 2.22; 95% CI, 1.42-3.46). Compared to men with more than 12 years of schooling, women with less schooling were at especially increased risk for major depression over the course of the 1-year follow-up interval (RR = 3.26; 95% CI, 1.78-5.95).