Parents often say their children bring them joy but most research suggests kids cause financial worry, stress and anxiety.
However, the latest research suggests children do actually make people happier - but only once they've left home.
Researchers led by Christoph Becker at Heidelberg University in Germany found people whose children have flown the nest have greater life satisfaction and fewer signs of depression. This is because they rely on their children to help them out financially and provide care, which outweighs the stress of raising them.
The team looked at 55,000 people over the age of 50 living in 16 European countries and asked them to rate their life satisfaction from 0 (completely dissatisfied) to 10 (completely satisfied).
Scientists found that adults with grown-up children scored between 0.02 and 0.56 points higher on the scale.
Dr Becker told The Independent: "That is, of course not an extremely big difference, but it comes from a data set with thousands of respondents. Hence, while children might not be the biggest driver of life satisfaction and happiness it has on average still a significant influence."
They found that adults who have regular contact with their children are happier than parents who still live with their children or never had them.
Dr Becker said: "We build on a lot of pre-existing literature and rather than finding some completely unique new result for children, we lend further evidence to the literature suggesting that children correlate with higher happiness under specific circumstances."
Researchers also found that marriage was "consistently positively correlated with wellbeing and lack of depressive symptoms".
The findings show social networks are also an important determinant for well-being and happiness - it is not just about being married or having children but having people to share feelings and thoughts with too.
"Taken together, our results suggest that social networks may be important for wellbeing and mental health in old age. Spouses, partners and children are often the basis of long-lasting social networks, which can provide social support to elderly people," according to the study, published in Plos One.
"While results on parenthood might be controversial and depend on the age of the studied population, there is widespread agreement that social support is associated with higher life satisfaction, and that social networks are an important factor for wellbeing."