Lead Exposure May Affect Mental Health
As levels increase, so does depression, anxiety and panic disorder, study finds
TUESDAY, Dec. 8, 2009 (HealthDay News) -- Young adults with elevated levels of lead in their blood might be at increased risk for major depression and panic disorders, a new study suggests.
Researchers analyzed information on 1,987 adults, aged 20 to 39, who took part in the U.S. National Health and Nutrition Examination Survey between 1997 and 2004. Of those participants, 134 (6.7 percent) had major depression, 44 (2.2 percent) had panic disorder and 47 (2.4 percent) had generalized anxiety disorder. The average level of lead in the blood among all participants was 1.61 micrograms per deciliter.
The 20 percent of participants with the highest lead levels (2.11 micrograms per deciliter or more) were more than twice as likely to have major depression and nearly five times more likely to have panic disorder than the 20 percent of participants with the lowest blood lead levels (0.7 micrograms per deciliter).
The study is published in the December issue of the Archives of General Psychiatry.
"These findings suggest that lead neurotoxicity may contribute to adverse mental health outcomes, even at levels generally considered to pose low or no risk," wrote Maryse F. Bouchard, of the University of Montreal and the Harvard School of Public Health. "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 researchers theorized that low-level lead exposure disrupts brain processes associated with depression and panic disorders, triggering their development in people predisposed to the conditions, making the conditions more severe or reducing the response to treatment.
The U.S. Agency for Toxic Substances and Disease Registry has more about lead.