http://well.blogs.nytimes.com/2015/10/26/the-ambivalent-marriage-takes-a-toll-on-health/
The New York Times, Tara Parker-Pope reports that the health benefits of marriage are linked to how supportive and understanding the relationship is. Ambivalent, unhappy relationships cause stress and have a negative impact on cardiovascular health. While the studies are not conclusive, they do demonstrate that something as simple as a happy couple holding hands had the calming effect of pain relieving drugs.