Men's physical health probably improves because of their partner's positive influence on their lifestyle and "the mental bonus for women may be due to a greater emphasis on the importance of the relationship", they write.
But the journey of true love does not always run smoothly, maintain the authors, pointing to evidence that relationships in adolescence are associated with increased adolescent depressive symptoms.
And not all relationships are good for you, they add, referring to evidence that single people have better mental health than those in strained relationships.