Although it occurs most often in mothers, fathers can also suffer postnatal depression and it can influence their children's early behavior, British researchers said on Friday.
Baby boys seem to be particularly affected by depressed dads and have twice as many behavioral problems in their early years as other children.
"Our findings indicate that paternal depression has a specific and persisting detrimental effect on their children's early behavioral and emotional development," said Dr Paul Ramchandani of the University of Oxford.
In a report published in The Lancet medical journal, Ramchandani and his team studied behavior and mental health of 12,800 couples in the first few weeks after the birth of their child and shortly before the children's second birthday.
They also assessed their children's emotional development and behavior when they were 3 years old from questionnaires filled out by the mothers.
"The relationship between boys' behavioral development and depression in their fathers is striking," Ramchandani said.
"It may be that boys are specifically sensitive to the effects of parenting by fathers, perhaps because of different involvement by fathers with their sons," he added.
Postnatal depression is a well-known phenomenon, affecting 13 percent of all new mothers. Its symptoms range from mild to severe.
An earlier study had found that about 3 percent of fathers showed signs of depression after the birth of a child.
"The influence of fathers in early childhood might have been underestimated in the past," said Ramchandani.
"Although our findings need to be confirmed and expanded, we believe that after the birth of a child, depression in fathers, as well as depression in mothers, should be actively considered," he added.
