Lead exposure may put children at risk of depression

Low-levels blood lead concentrations in children are associated with the presence of depressive symptoms in later childhood, according to a study.

The study included 218 caregiver-child pairs (children: mean age 12.4 years, 55.5 percent female, 35.8 percent Black) who were followed up from the second trimester to age 12 years. Serial blood lead concentrations in children were measured at ages 1, 2, 3, 4, 5, 8, and 12 years. Child depressive and anxiety symptoms at age 12 years were assessed using the Behavioral Assessment System for Children–3 (BASC-3), Children’s Depression Inventory–II (CDI-II), and Screen for Child Anxiety Related Disorders (SCARED).

The median within-child mean blood lead concentration was 9.6 μg/L. Blood lead concentrations declined from 12 to 144 months of age, with the greatest variability observed in early childhood.

Each doubling in mean childhood blood lead concentrations was associated with a greater likelihood of elevated child-reported depressive symptoms on the BASC-3 (relative risk [RR], 1.90, 95 percent confidence interval [CI], 1–3.66; p=0.05) and child- and caregiver-reported child depressive symptoms (RR, 1.76, 95 percent CI, 1.12–2.78; p=0.02).

Blood lead concentrations showed no associations with self-reported depression measured on the CDI-II or anxiety measured on the SCARED. Sex and race did not influence the associations.