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Biomarker of pesticide exposure tied to depressive symptoms among teens

Study findings published in International Journal of Hygiene and Environmental Health indicated a link between a biomarker of pesticide exposure and youth depression symptoms.

Teenagers in agricultural communities whose acetylcholinesterase activity indicated greater exposure to cholinesterase inhibitor pesticides had greater depression symptoms than those with less exposure, the results showed.

Prior research has shown a positive association between exposures to pesticides and depression among agricultural workers and residents living in agricultural areas in Latin America, Europe and the U.S., Jose Suarez-Lopez, MD, PhD, MPH, of the University of California San Diego, and colleagues wrote.

“To our knowledge, no human studies have used biomarkers to assess pesticide exposures in relation to depression and anxiety,” they wrote. “Consequently, the absence of precise measures may result in exposure misclassification, threatening the validity of findings.”

The researchers examined acetylcholinesterase (AChE) activity using a finger-stick samples from 529 youth aged 11 to 17 years from agricultural communities in the Ecuadorian Andes. Symptoms of depression and anxiety were assessed using the Children’s Depression Inventory (CDI-2) and Multidimensional Anxiety Scale for Children (MASC-2), where greater scores indicated greater internalizing symptoms.

Suarez-Lopez and colleagues found that lower AChE activity, which indicated greater cholinesterase inhibitor pesticide exposure, was linked to higher depression symptoms (difference per standard deviation reduction in AChE: beta = 1.09; 95% CI, 0.02-2.16).

This association was stronger among girls (beta = 1.61) vs. boys (beta = 0.69) and among younger youth (beta = 1.61) compared with older youth (beta = 0.57), according to the results. In addition, girls aged older than 14 years (the median age) exhibited the strongest association between pesticide exposure and depressive symptoms (OR for greater symptoms per standard deviation reduction in AChE = 2.58; 95% CI, 1.26-5.27).

However, the researchers found no associations between lower AChE and increased anxiety symptoms.

"Agricultural workers and people in these communities have long offered anecdotal reports of a rise in adolescent depression and suicidal tendencies," Suarez-Lopez said in a press release. "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." – by Savannah Demko

Disclosure: The authors report no relevant financial disclosures.