Decades of lead exposure from car exhaust altered the mental health of millions of Americans, making them more prone to depression, anxiety and ADHD, a new study claims.

Decades of leaded gasoline exposure in the United States linked to mental health conditions such as depression, anxiety, ADHD and neurotic behavior.

Writ large, across the population, we’ve shifted the curve away from normal, healthy functioning and towards greater rates of mental illness,” says Aaron Reuben, a study co-author and clinical neuropsychologist at the University of Virginia,

New research estimates that lead exposure from gasoline has significantly affected Americans' mental health for the worse during the 20th century.