Studies have linked spanking children to everything from developmental delays, to aggressive behavior to true crime. Now, add mental illness to that long list.

A new Canadian study, just published in the journal Pediatrics, examines the relationship between physical punishment and a wide range of mental disorders. The team used data from a U.S. survey done from 2004 to 2005.

Harsh physical punishment such as pushing, grabbing, shoving, slapping or hitting was associated with increased odds of mood disorders, anxiety disorders, alcohol and drug abuse, and several personality disorders. Researchers found 2 percent to 7 percent of mental disorders were attributable to harsh physical punishment.

Banned in some countries, studies show that spanking has declined in the United States since the 1970s. However, many parents still believe it's an acceptable form of punishment. A 2010 study revealed that nearly 80 percent of preschool children in the United States are spanked.

I'm Dr. Cindy Haines of HealthDay TV, with the latest breakthroughs from the world of medicine.