Purpose: The purpose of the study presented is to evaluate the association between pesticides and depressive symptoms among a population exposed to chemicals as a result of agricultural use. Chronic sequelae of acute pesticide poisoning from organophosphate compounds may include anxiety and depression. In some states, farmers have been reported to have higher rates of depression than other population groups. Little work has been done to describe the effects of exposure to organophosphate compounds and depressive symptoms among the farming population.
Methods: Data for this study came from a cross sectional survey of farmers and their spouses conducted in an eight county area in northeastern Colorado. Personal interviews were conducted with the study participants. Depressive symptoms were assessed using the Center for Epidemiologic Studies-Depression (CES-D) scale. Pesticides applied on the farms were assessed using self-reported questionnaires. Conditional logistic regression was used to model the relationship between depression and pesticide-related illness in a stratified analysis.
Results: Between 1992-1997, 761 individuals were enrolled in this cross sectional survey. Adjusting for a number of potential confounders, the odds ratio for depression associated with pesticide-related illness was 5.87 [95% confidence interval (CI) = 2.56-13.44].
Conclusions: Exposure to pesticides at a high enough concentration to cause self reported poisoning symptoms was associated with high depressive symptoms independently of other known risk factors for depression among farm residents.