"Dads that were depressed were nearly four times more likely to spank their one year old children," said Dr. Neal Davis, a pediatrician with Intermountain Healthcare.
Davis is the lead author on the study, found in the March 14, 2011, journal "Pediatrics."
He says postpartum depression affects one in 10 fathers in America.
The study shows of the 1,746 fathers surveyed nationally, about 40 percent said they spanked their kids age 1 and under.
"This young dad came in and he was interested in getting help for his depression because he had a 4-month-old daughter," said Davis. "He recognized that he was having those symptoms and he didn't want that to affect his relationship with his daughter."
It's a scenario that's been around for some time, Davis said, but it's just now coming to the surface.
"For men that can be symptoms of sadness or lack of interest in doing things they like to do," said Davis. "Or in particular, irritability or frustration."
Men typically don't like to admit they suffer from depression, which tends to fuel the problem.
"Men frequently don't get depressed like we would see it, you know, sleeping all day and crying.
It's not a masculine thing to do, is get tearful," said Martha Burkett-Fallis, Licensed Clinical Social Worker with the Utah Domestic Violence Council. "It represents itself more in anger."
It's a scenario that social workers like Burkett-Fallis are seeing a lot of these days.
"I'm feeling stressed and low and I don't really want to do much so I'll get angry," said Burkett-Fallis. "And if I get angry, I'm motivated and I can get things done. And that just kind of splashes out on everybody in the vicinity."
One of the main risk factors for a dad who will beat his newborn, says Dr. Davis, is a father who is out of work.
One coping strategy for men dealing with postpartum depression is to talk about their symptoms and feelings with their child's pediatrician.
"If men are honest with themselves," said Davis. "They can realize that they may be having some of those symptoms and then don't be afraid to talk about it."
Also, experts suggest taking a break from the situation and seeking help from others around you who can help ease the load of caring for a newborn.
"Take a break. Get some sunshine. Depression and sunshine aren't very good friends," said Burkett-Fallis. "The more sunshine you get the happier you seem to be. Get some exercise. Sleep. Sleep doesn't really come with infants. That's one of the things you lose the most of."