Lead is a ubiquitous neurotoxicant, and adverse cognitive and behavioral effects are well documented in children and occupationally exposed adults but not in adults with low environmental exposure.
To investigate the association of current blood lead levels with three common psychiatric disorders, major depression, panic, and generalized anxiety, among young adults.
Cross-sectional epidemiologic survey.
Representative sample of non-institutionalized United States adults.
A total of 1,987 respondents of age 20–39 years to the National Health and Nutrition Examination Survey conducted from 1999 to 2004.
Main Outcome Measures
Twelve-month DSM-IV criteria-based diagnoses of major depressive disorder, panic disorder, and generalized anxiety disorder assessed by the Composite International Diagnostic Interview.
Mean blood lead level was 1.61 μg/dL (SD 1.72, range 0.3–37.3 μg/dL). Increasing blood lead level was associated with higher odds of major depression (p for trend 0.05) and panic disorder (p for trend 0.02), but not generalized anxiety disorder (p for trend 0.75), after adjustment for sex, age, race/ethnicity, education, and poverty-income ratio. Persons with blood lead level in the highest quintile had 2.3 times the odds of major depressive disorder (95% CI 1.13 – 4.75) and 4.9 times the odds of panic disorder (95% CI 1.32 – 18.48) as those in the lowest quintile. Cigarette smoking was associated with higher blood lead level and the outcomes, but models excluding current smokers also resulted in significantly increased odds for major depression (p for trend 0.03) and panic disorder (p for trend 0.01) with higher blood lead quintile.
In this sample of young adults with low levels of lead exposure, higher blood lead was associated with increased odds of major depression and panic disorder. Exposure to lead at levels generally considered safe could result in adverse mental health outcomes.