New research shows there is a strong correlation between water fluoridation and the prevalence of Attention Deficit Hyperactivity Disorder, or ADHD, in the United States.
It's the first time that scientists have systematically studied the relationship between the behavioral disorder and fluoridation, the process wherein fluoride is added to water to prevent cavities.
The study, published in the journal Environmental Health, found that states with a higher portion of artificially fluoridated water had a higher prevalence of ADHD. This relationship held up across six different years examined. The authors, psychologists Christine Till and Ashley Malin at Toronto's York University, looked at the prevalence of fluoridation by state in 1992 and rates of ADHD diagnoses in subsequent years.