Prenatal lead exposure linked with increased risk of depression in adulthood
Prenatal exposure to lead—especially during the third trimester—may lead to significantly higher risk for major depressive disorder and anxiety symptoms in later adulthood, according to a new study led by Harvard T.H. Chan School of Public Health.
The study was published Oct. 22 in JAMA Psychiatry and was the subject of a Nov. 3 Medscape article.
Although it’s known that early lead exposure is associated with psychological issues in childhood—such as behavioral problems and delayed development—less is known about whether lead-related issues may persist into adulthood. To learn more, researchers measured lead exposure in baby teeth that had been collected from the 1950s to 1970s as part of the Saint Louis Baby Tooth – Later Life Health Study. Teeth were analyzed using a technique in which a small portion of a tooth is vaporized by a laser and then ionized so that its elements can be detected by a mass spectrometer. In this way, researchers were able to determine the amount of lead exposure and when it occurred. They looked at a single tooth from each of 718 participants and asked those individuals—at that point in their 60s—to answer survey questions aimed at measuring symptoms of depression and anxiety.
Among the participants, those who were in the highest quartile of exposure to lead during the third trimester of pregnancy had more than a 50% higher risk of major depressive disorder than those in the lowest quartile of exposure. Women faced a higher risk than men. Late prenatal and postnatal lead exposure were also associated with greater anxiety symptoms in later adulthood, the researchers found.
“Our findings suggest that early lead exposure may have lasting implications on mental health well beyond childhood and adolescence,” Joyce Lin, postdoctoral research fellow and lead author of the study, told Medscape. “These results, considered alongside findings from other follow-up studies, suggest that public health interventions to reduce lead exposures, even before birth, could deliver mental health benefits that last well into adulthood.”
Other Harvard Chan authors of the study included MPH student Ruby Hickman, PhD student Justin Farmer, postdoctoral research fellow Michael Leung, former research associate Ian Tang, research assistant Kaleigh McAlaine, and Marc Weisskopf, Cecil K. and Philip Drinker Professor of Environmental Epidemiology and Physiology.
Read the Medscape article: Prenatal Lead Exposure Tied to a Significant Risk for Major Depression
