Study shows a link between frequent exposure to insecticides and a higher risk of depression and anxiety in Ecuadorian teenagers

The study was conducted in Ecuador by Dr. Jose Suarez-Lopez, an assistant professor at the University of California-San Diego. He and colleagues “have been tracking the development of children living near agriculture in the Ecuadorian Andes since 2008,” a university press release said. “Ecuador is the world’s third-largest exporter of roses, with much of the flower production located near the homes of participants. Like many other agricultural crops, flowers are routinely sprayed with organophosphate insecticides, which are known to affect the human cholinergic system, a key system in the function of the brain and nervous system.”

Researchers measured blood levels in 11- to 17-year-olds of an enzyme that is inhibited by organophosphates. Studies in mice had shown that reduced levels of the enzyme were linked to “behaviors of anxiety and depression in mice, and a few existing studies in humans have also suggested such a link,” the release says. “However, pesticide exposure assessment in past studies had been only established by self-report of exposure and not using biological measures.”

The study found that teens who had reduced enzyme levels, suggesting greater exposure to , showed higher-than-normal symptoms of depression. “The association was stronger for girls, who comprised half of all participants, and for teens younger than 14,” the release says. It quotes Suarez-Lopez:  “Agricultural workers and people in these communities have long offered anecdotal reports of a rise in adolescent depression and suicidal tendencies. This is the first study to provide empirical data establishing that link using a biological marker of exposure, and it points to a need for further study.”