That %&#@$%$ Semen-Antidepressant Study

Attention ladies!

Every once in a while, this story comes back into the news cycle and, every time, it just gets worse. In brief: some researchers conducted a study where they looked at the sexual practices and moods of female college students – 293 of them – and found that those women who were having unprotected sex were less depressed. From this, they concluded that semen has antidepressant properties.

I first read something about this study several years ago when a story about it appeared online in Psychology Today. The date on the Psychology Today article implied that this was groundbreaking, new research, but the original research was actually from 2002. Looking for that article the other day, I found this brand new one, where the author, Michael Castleman, admits a fascination with the “chemical complexity of semen”, but fails to mention how old the study is. Nor did he seem to check to see if anyone has tried to replicate it. I’m guessing he didn’t read it. He does include this unhelpful bit of advice, though:

Now, I’m not advocating that reproductive-age people shun condoms to elevate women’s mood at the risk of unplanned pregnancy. But this effect might come in handy for women over age 50, who are experiencing menopausal blues.

Because unplanned pregnancy is the only worry here? Here’s a hint. Women over 50 can get disease just as easily as the younger, fertile ladies. In fact, they can be at higher risk. And, no, they are not all married or in monogamous relationships. And, he’s suggesting women over 50 try this to cure their depression on the basis of a single, preliminary, nine year-old, unreplicated study involving less than 300 women of college-age?

This is not the same as suggesting someone try eating more fish or getting more exercise to stave off depression. Yet, even then, you may be warned to discuss any changes in lifestyle with your doctor. Only one fifth of women report ever discussing sex with their doctor after they’ve turned 50. This guy is dispensing health advice – that is not benign – to a group of people who are known to not discuss this sort of thing with their doctors.

Consider that 10% of all new AIDS cases occur in adults over 50. It is estimated that by 2015, half of the people in the U.S. living with HIV/AIDS will be over 50 (in many ways, this is good news, as it reflects, in part, that people with the disease are living longer). However. most older adults are not diagnosed until a later stage of the disease, which means they may have been infected and potentially have been infecting others for a long time without knowing. Age-related changes in the vaginal walls put older women at a higher risk of infection during intercourse than younger women.  And you can find more information here.

I’d also like to point out that Psychology today links to the story “Semen is an Antidepressant” under “Combination Therapy” on their “Psych Basics: Antidepressants” page which presumably is the sort of “basics” page geared towards consumers.

The study’s authors, Gallup, Burch and Platek, are quite clear that it is preliminary,

It is important to acknowledge that these data are  preliminary and correlational in nature, and as such are only suggestive. More definitive evidence for antidepressant effects of semen would require more direct manipulation of the presence of semen in the reproductive tract and, ideally, the measurement of seminal components in the recipients blood.

Did Castleman read this? Has anyone at Psychology Today read it? Are they basing all of their – repeated – stories on this topic on a single press release from way back when? It’s not a health story. If it was any kind of story at all, it would be an interesting evolutionary one. But let’s go ahead and investigate a bit more why someone might not think it’s a story at all.

There are some other caveats with regards to the study. First, the study utilized self-report questionnaires – people filling out these questionnaires may not answer truthfully, they may not remember things correctly and they certainly can’t be used to show causation. The study was also only done on students. A sample of college students is often considered a “convenience sample”.  The results may not necessarily extend to a larger population. Often in these cases, researchers can point to other studies that found similar results in different or more diverse populations. Although, there don’t seem to be any other studies out there focusing on semen and depression, in this study, a lack of condom use was considered an indirect measure of semen in the reproductive tract. So, really what they were measuring was condom use. There are plenty of studies looking at condom use and mental disorders and these tend, overwhelmingly, to suggest that not using condoms (and, indirectly, getting semen) is associated with depression and other mental health issues. For example, in Relationship Between Mental Disorders/Suicidality and Three Sexual Behaviors: Results from the National Comorbidity Survey Replication:

Never married participants who rarely/never used condoms were more likely than those who always used condoms to experience any mood, substance use, and any mental disorder, and suicide attempts.

These results came from a representative sample of adults – not just college students – numbering 5,692 – not 293.

In the authors’ discussion of alternate explanations for the results, they consider the possibility that the type of women who don’t use condoms are more likely to be happy anyway and then discount it, but they don’t consider whether the type of women who do use condoms are less likely to be happy anyway. Perhaps they worry more. I don’t have any idea whether this is true or not, but it is an alternate explanation that they did not consider in the  paper.

In yet another Psychology Today article on this topic from 2002 (because they just can’t get enough of this story over there), the author indicates that Gallup

has since replicated the findings with a sample of 700 women and will examine whether “semen withdrawal” places women at an  increased risk for depression when they are premenstrual, menopausal or  have just given birth, as many women abstain from sex during these periods.

But I looked through Gallup’s CV and can’t find a follow-up study anywhere. I even went to the library after work where I read a chapter co-written by two of the authors from the original study, Burch and Gallup, on the Psychobiology of Human Semen. Here, they do cite their unpublished results – frequently. However, since they are unpublished, it’s hard to really say anything about them. The rest of the chapter is just a bunch of theories with very little evidence to support anything. It seemed as if half of all statements included “…it is possible that semen could…” At a certain point, this kind of thing gets out of hand and it’s time to actually do a useful, concrete study looking at how much of these substances are in semen, how much ends up in the bloodstream through vaginal delivery and whether a change of that amount can cause the effects they are claiming it “could” cause.

On the other hand, once I got to the part where they began talking about men “developing a homosexual orientation as a consequence of an early same-sex sexual encounter among males” being somehow dependent on whether there was any semen exchanged, I began to realize that my attempts to take this seriously were, perhaps, misguided.

And the thing is that the idea itself is not crazy. If people feel good after having sex, they are going to seek out more of the same.  So, if the semen in certain men led women to feel happier after sex, then these men might have ended up being more popular and may have produced more offspring thereby increasing the happy-semen trait in the population. The idea isn’t bad, it’s just that this smallish, decade-old study doesn’t really prove anything and is easily dwarfed by a good deal of better quality evidence that contradicts it. The repeated, smirking suggestions that sad ladies might try to solve their problem by getting some man-juice is not helpful. It’s so bad, it’s making me want to use ALL-CAPS.

Journalists – and this surgeon  -  need to be aware that not all information is created equal. It needs to be presented truthfully. They might as well be lying if they leave important information out. That this is a preliminary study that was never followed up and contradicts a great deal of other, better evidence is important. So, important, that it kind of implies that the study isn’t worth writing about.

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Burch RL, Gallup, GG Jr  Psychobiology of Human Semen. In: Platek SM, Shackelford T, editors. Female Infidelity and Paternal Uncertainty. Cambridge University Press; 2006. P. 414-72.

Gallup GG Jr, Burch RL, & Platek SM (2002). Does semen have antidepressant properties? Archives of sexual behavior, 31 (3), 289-93 PMID: 12049024

Golub SA, Tomassilli JC, Pantalone DW, Brennan M, Karpiak SE, & Parsons JT (2010). Prevalence and correlates of sexual behavior and risk management among HIV-positive adults over 50. Sexually transmitted diseases, 37 (10), 615-20 PMID: 21305717

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