In a 2002 study done at SUNY Albany, 293 college women answered questionnaires about their sexual histories and took the Beck Depression Inventory (BDI), a commonly used criterion for gauging depression symptoms. Women who always had sex with men without using condoms had significantly lower levels of symptoms of depression than those who never or infrequently had unprotected sex, as well as those who abstained from sex entirely. There was no noticeable difference in depression between condom users and people who didn’t have sex, indicating that intercourse itself wasn’t the mood-boosting factor.
“A February, 2011 article on mating written by the president of the American College of Surgeons made the 2002 study relevant again. Read more here.”
Article source: Popular Science online