In the prologue to my soon-to-be-published book The Wisdom of Whores, I give an example of the different ways nerds like me look at cause and effect in health. When I was writing it, I made up an example out of the air — something that I thought that people would relate to and be amused by, but not take too seriously. I hit upon the link between sex and depression.
Now, guess what? Australian researchers have gone and done the study. With results I wouldn’t have expected.
The passage in The Wisdom of Whores read:
In the first lecture, we ”reviewed” all the major study types. For example the case-control study, where you find a group of people with a disease, and then look for people who are much the same but without the disease. You compare the two groups to see if they have different risks. It’s a relatively cheap method, but it doesn’t tell you much about the order in which things happen. I can’t remember all the examples used in the lecture, but let’s say you want to look at causes of depression in women. You start with 600 depressed women, find another 600 who match them on age, ethnicity and educational status, and then ask them all about their lives. Let’s say you find out that women who are depressed are six times more likely not to have had sex in the last year as women who are cheerful. That means if you’re not having sex you get depressed, right? But hang on, couldn’t it be that women who are moping around looking miserable don’t get laid much?
Perhaps you’d be better off with a cohort study. You start off with several thousand women who are perfectly happy. Then you follow them over time, recording their behaviours, and see which of them get depressed. If you find that women who have sex are less likely to become depressed than women who aren’t getting any, it suggests it is the lack of sex that causes the depression, not the depression which stops you getting laid. You can throw out the “misery guts” theory and recommend more good sex as an intervention to promote mental health.
The Australian research, led by Sabura Allen, isn’t published in full yet. But according to an AAP report, they found that depressed women have more sex than happy women, at least in Melbourne where the study was conducted. I’m looking forward to seeing the full paper. But I’d be prepared to bet that these results come from a cross-sectional study, not one that follows women over time. If I’m right, we’re still left with the question, which come first, the depression or the sex?
As Melbourne stalwarts Rob Moodie and Gabriel Gate say in their wonderful new book “Recipes for a Great Life”, “We want to be held,kissed, caressed. It’s why we seek relationships”. To this extent, they seem to agree with Allen, who advances the theory that women who are a bit miserable go looking for sex because it makes them feel better. But the Melbourne Life Cooks recipe for better sex? “Have Fun”. Which leaves me with an alternative hypothesis about the link between sex and sadness for women. Perhaps they’re not having fun. Perhaps men in Melbourne are just not very good at sex. That would be depressing…