It was 50pc lower among women who adopted, the study published online in the Journal of Epidemiology and Community Health showed.
Rates of death were around twice as high among men who did not become parents, either biologically or through adoption. Rates of mental health problems were similar between couples with or without children of their own, with the exception of those with drug and alcohol problems.
But the prevalence of mental illness in couples who adopted children was around half that of other parents.
"Mindful that association is not causation, our results suggest that the mortality rates are higher in the childless," the authors, from Aarhus University in Denmark concluded.
"Rates of psychiatric illness do not appear to vary with childlessness, but the rate of psychiatric illness in parents who adopt is decreased."