New research suggests an intriguing link between the amount of lead found in a person’s blood and their likelihood to be diagnosed with depression, anxiety disorder or panic disorder in younger adults.
“Our findings support previously reported associations of mood and anxiety disorders with high occupational lead exposure and less well-documented association with lower environmental levels of exposure in older men,” noted the researchers.
The study, led by Maryse F. Bouchard at the University of Montreal, examined 1,987 adults aged 20 to 39 years old who responded to the National Health and Nutrition Examination Survey (1999-2004). A structured, diagnostic interview was used to obtain mental health diagnoses of the subjects.
The researchers found that increasing blood lead levels were associated with higher odds of major depression and panic disorder, but not generalized anxiety disorder after adjusting for other variables, including gender, age, race/ethnicity, education status, and poverty-to-income ratio.
Subjects with the highest blood lead levels had 2.3 times the odds of major depressive disorder and 4.9 times the odds of panic disorder as those with the lowest blood lead levels.
“We observed that increasing blood lead levels were associated with a significantly higher risk of [depression] and [panic disorder] in young adults in the United States,” wrote the researchers.
Cigarette smoking was associated with higher blood lead levels and increased likelihood of being diagnosed with a mental disorder, but models that excluded current smokers also resulted in significantly increased odds of major depression and panic disorder with higher blood lead levels.
“These findings suggest that lead neurotoxicity may contribute to adverse mental health outcomes, even at levels generally considered to pose low or no risk,” the researchers concluded.
“These findings, combined with recent reports of adverse behavioral outcomes in children with similarly low blood lead levels, should underscore the need for considering ways to further reduce environmental lead exposures.”
The study appears in the December issue of the Archives of General Psychiatry.
Source: Archives of General Psychiatry