New baby depression is not exclusive to women, but can affect men as well, according to New Zealand research.
While pre-natal and post-natal depression has been examined extensively in mothers, fathers were often left out in the cold, an Auckland University study says.
The study, published in the Journal of the American Medical Association Psychiatry, investigated depression symptoms in more than 3500 New Zealand men.
Researchers found that 2.3 per cent of fathers had experienced depression during the pregnancy, rising to 4.3 per cent nine months after the birth.
Men most at risk of depression symptoms either felt stressed or were in poor health.
Additional post-natal risks included a history of depression, unemployment and - the strongest predictor - no longer being in a relationship with the child's mother.
Study author Dr Lisa Underwood says there is a growing awareness of the influence that fathers have on their children's psychosocial and cognitive development.
"Given the potential for paternal depression to have direct and indirect effects on children, it is important that we recognise and treat symptoms among fathers early," she said.
"Arguably, the first step in doing this is to raise awareness about factors that lead to increased risks among fathers themselves."