Now We Know Why Lesbians Are So Grumpy

Courtesy of this story from Psychology Today:
The finding that women who do not use condoms during sex are less depressed and less likely to attempt suicide than are women who have sex with condoms and women who are not sexually active, leads one researcher to conclude that semen contains powerful—and potentially addictive—mood-altering chemicals.

Study author Gordon G. Gallup, Ph.D., a psychologist at the State University of New York in Albany, also found that women who routinely had intercourse without condoms became increasingly depressed as more time elapsed since their last sexual encounter. There was no such correlation for women whose partners regularly used condoms.

Gallup's survey of 293 college women also found that those who did not use condoms were most likely to initiate sex and to seek out new partners as soon as a relationship ended. "These women are more vulnerable to the rebound effect, which suggests that there is a chemical dependency," says Gallup.

Semen contains hormones including testosterone, estrogen, prolactin, luteinizing hormone and prostaglandins, and some of these are absorbed through the walls of the vagina and are known to elevate mood.
Quick thoughts: These days, unless her partner has tested negative for STDs including HIV, any woman who is having unprotected sex is at best ignorant of the risks she is taking and at worst not-quite-bright (even if she is a college student). We won't even throw the risk of pregnancy into the mix, since there are other alternative methods of birth control, but none of them protect against STDs. If ignorance is bliss, then it's no wonder that the no-condom girls are blissfully happy.

And for the guys, before you go out and start making girls "happy" without a love glove, remember that if the little wigglers catch, you're on the hook for child support until the kid is grown. Her mood will be elevated; yours won't.