This study prospectively examined shift work and change in depressive symptoms over a three-year period in 70 randomly selected police officers. The Center for Epidemiological Studies Depression (CES-D) scale was used to measure depression. Shifts were measured using data from daily payroll records over a five-year period prior to examination. Officers were classified by shift (day, afternoon, or night) based on the hours worked per shift. The association between shift work and change in CES-D scores was analyzed by analysis of variance. Mean age of the sample was 40.4 years; 61.4% were males. Officers working the day shift exhibited a trend toward greater mean increases in depressive symptoms (3.6+/-9.0) than those on afternoons (0.6+/-5.9) and nights (0 .9+/-4.5), p=0.287. Unmarried officers on day shifts had a larger increase in mean CES-D (7.9+/-9.7) compared to afternoon (1.6+/-4.0) or night (0.2+/-4.3) shifts, p=0.128. After adjustment for age, gender, and smoking status, the results were only slightly attenuated: day (7.1+/-2.3), afternoon (3.1+/-3.6), and night (0.9+/-4.0), p=0.413. In contrast, the mean change in CES-D was similar across shifts for married officers. Contrary to expectations, officers working day but not night shifts had an increase in depressive symptoms over time. Marital status appears to influence this association. Further research is needed to clarify additional factors associated with day shift work that may exacerbate depression.
American Journal of Epidemiology. Abstracts of the 42nd Annual Meeting society for Epidemiologic Research Anaheim, California, June 23-26, 2009