A Colorado State University study says farmers who used a specific kind of pesticide were almost six times more likely to suffer from depression than other farmers.
The pesticides are called organophosphates. They're related to nerve gas developed in World War II.
The study didn't suggest an underlying cause for the depression. Study co-author Lorann Stallones says many questions still need to be answered.
Alan Foutz of the Colorado Farm Bureau says there may be other causes of depression among farm families. He says they're under a lot of stress because of four years of drought.
The study was done by Stallones and Cheryl Beseler
They studied 761 northeast Colorado farmers and their spouses between 1992 and 1997.