The researchers re-analyzed 43 studies on this subject involving 28,000 men.
They say as many as 10 percent of men could suffer from depression sometime during pregnancy or during the first year after birth.
Rob Sandler was very exited to have a boy, but then came emotions he hadn't expected.
INTERACTION: WHAT DO YOU THINK?
"It was just a feeling of really complete sadness, really deep sadness." said Sandler. He adds, "I cried a lot. Sometimes uncontrollably and didn't sleep very well."
Rob said he felt disconnected from his newborn, and slammed with new responsibilities.
He was overwhelmed, and felt guilty, ashamed for feeling that way. It all started to spiral out of control.
"And I was thinking, God, this is never going to get any Better," adds Sandler.
Rob Sandler was suffering from Postpartum depression.
"Men's Postpartum Depression is surprisingly common," said Dr. Will Courtenay, Psychotherapist. He adds, "In fact a mans risk of Depression doubles in the 9 months after his child is born."
About 10 percent of new mothers experience severe postpartum depression. But men can experience it too.
Dr. Courtenay is a Psychotherapist in Berkeley, California whose researched it extensively, but was not involved in the study.
"Just like women men go through hormonal changes," Dr. Courtenay adds.
Men may have increased estrogen and decreased testosterone levels after birth.
Biologists believe this may be nature's way of keeping men around to care for the baby, but those hormone changes can also cause the blues.
Suddenly a new dad is left feeling more like an emotional wreck than the emotional rock society expects of him.
For Rob, he luckily sought help, with support from his wife.
"If there's something wrong, you-- you need to get help for it," said Traci Sandler.
Rob says he wasn't embarrassed by his condition. "There's nothing to be ashamed about. I think it takes a bigger man and a stronger man to go and realize that something's wrong, to get help than to let it fester and ruin your abilities to be a good father," he adds.
The study found that the most difficult period for men is when their newborn is 3 to 6 months old. And when mother's have Postpartum depression, there is a slight chance the husbands could too. And of course, depression also can affect the children.
The researchers who published the study say much more needs to be understood about this issue so we can better provide early identification and treatment.
The report published in Tuesday's journal of the American Medical Association was done by James Paulson, PH.D and Sharnail D. Basemore, MS at the Eastern Virginia Medical School in Norfolk.