LOS ANGELES (CBSLA) — Apparently only one thing can make you happier than having children — kicking those kids out of the house.

According to a new study led by researchers at the Heidelberg University in Germany, parents are happier than non-parents as they reach old age, but only if their children have grown up and moved out.

The study asked 55,000 people age 50 and older about their mental health and found that parents are happier because the stress of balancing childcare and work is replaced with a form of social support.

Researchers say that change is crucial to our happiness.