ErosBlog has done jokey and unserious posts before on various supposed medical effects of semen; see, e.g., Swallow, It’s Good For The Baby and Anal Sex: It DOES Make Your Butt Bigger. Now, however, I’m linking to research psychologist Jesse Bering’s blog post at Scientific American about completely serious (possibly wrong of course — science is ever fraught with peril — but still completely serious) research into the antidepressant effect on women of vaginal exposure to seminal fluid. It looks real and substantial, even leading to a measurable effect on suicide rates:

Semen has a very complicated chemical profile, containing over 50 different compounds (including hormones, neurotransmitters, endorphins and immunosupressants) each with a special function and occurring in different concentrations within the seminal plasma. Perhaps the most striking of these compounds is the bundle of mood-enhancing chemicals in semen. There is good in this goo. Such anxiolytic chemicals include, but are by no means limited to, cortisol (known to increase affection), estrone (which elevates mood), prolactin (a natural antidepressant), oxytocin (also elevates mood), thyrotropin-releasing hormone (another antidepressant), melatonin (a sleep-inducing agent) and even serotonin (perhaps the most well-known antidepressant neurotransmitter).

Given these ingredients–and this is just a small sample of the mind-altering “drugs” found in human semen–Gallup and Burch, along with psychologist Steven Platek, now at the University of Liverpool, hypothesized that women having unprotected sex should be less depressed than suitable control participants. To investigate whether semen has antidepressant effects, the authors rounded up 293 college females from the SUNY-Albany campus, who agreed to fill out an anonymous, written questionnaire about various aspects of their sexual behavior. Recent sexual activity without condoms was used as an indirect measure of seminal plasma circulating in the woman’s body. Each participant also completed the Beck Depression Inventory, a commonly used clinical measure of depressive symptoms.

The most significant findings from this 2002 study, published with criminally modest fanfare in the Archives of Sexual Behavior , were these: even after adjusting for frequency of sexual intercourse, women who engaged in sex and “never” used condoms showed significantly fewer depressive symptoms than did those who “usually” or “always” used condoms. Importantly, these chronically condomless, sexually active women also evidenced fewer depressive symptoms than did those who abstained from sex altogether. By contrast, sexually active women, even really promiscuous ones, who used condoms were just as depressed as those practicing total abstinence. In other words, it’s not just that women who are having sex are simply happier, but instead happiness appears to be a function of the ambient seminal fluid pulsing through one’s veins.

And it gets better. A smaller percentage (4.5 percent) of the sexually active women who “never” used condoms were less likely to have attempted suicide than were those who “sometimes” (7.4 percent) and “usually” (28.9 percent) and “always” (13.2 percent) used condoms.

The usual scientific disclaimers, especially those about correlation, causation, and confounding factors, do apply and have not been neglected; whether they’ve been adequately considered is beyond my scientific skill to discern. Of somewhat greater concern is the fact that this knowledge, if knowledge it be, is potentially dangerous if thoughtlessly put to use in your sex life. As Jesse Bering put it:

[A]lthough the data and information … oozes with the promise of dramatically improving virtually every aspect of your wellbeing, it can also be abused with tragic–even fatal–consequences. This is so much the case, in fact, that I debated the merits of popularizing this material and do so here only with great circumspection and caution. So please be wise in digesting this semen-related knowledge, and be wiser still in applying it to your own sex lives.

[K]nowing that the penis is capable of dispensing a sort of natural Prozac … without also considering the viral arms race involving sexually transmitted infections, can lead to very tragic decisions indeed and many undocumented high-risk private bedroom “experiments.” But here’s just one reason to put the brakes on such plans: The HIV-virus, which evolved long after these adaptive antidepressant factors, has apparently come to pirate human semen, such that certain protein factors in seminal plasma, particularly a protein called prostatic acid phosphatase , make HIV up to 100,000 folds more potent than it is outside of the plasma.

Verbum sapienti satis est.