Forty percent of depressed men said they spanked their 1-year-old child in the last month.

Dads feeling blue are more likely to spank their young children than dads in good spirits, US researchers have found. Forty percent of depressed men said they had spanked their kids in the last month, compared to only 13 percent of men without symptoms.

The researchers analyzed data gathered between 1999–2000 from 1,746 fathers from 16 US cities. Men were questioned about depression symptoms, spanking and interactions with their 1-year-olds. They weren’t, however, asked why they spanked or if a spanking resulted in any harm to the child.

Depression among fathers is strongly tied to unemployment, both of which are higher now than they were a decade ago. Although spanking can result in both physical and mental harm on a child, many people believe spanking is sometimes necessary. In a 2008 survey, 77 percent of men and 65 percent of woman said a child sometimes needs a “good hard spanking.” The new study doesn’t necessarily prove that depression leads to spanking in itself, but it does prove that dads feeling down were four times more likely to hit their children.